file: fox97.html
collected by: [email protected]
02 Jan 1997
Brian
fordnatics
The following is from Mustang Performance Handbook II by William R. Mathis:
Recommended Backspacing and Offsets
Front Tire - Given tire section width of 255mm for stock mustang
5.75" on 10" wheel
5.50" on 9.5" wheel
5.25" on 9" wheel
4.75" on 8" wheel (minimum width)
or and offset of 3/4" negative camber
Generally 245/45ZR16 on a 9" wheel is the limit on stock front end.
Rear Tire - Given tire section width 275mm (with rear fender and wheel well
modifications [roll fender lip.])
5.25" on 10" wheel
5.50" on 9.5" wheel
5.75" on 9" wheel
or and offset of .25" negative camber.
This is generally for road racing, since drag cars eventually go to slicks and
tubs. But you get the picture.
30 Jan 1997
"K.M. Sen-Roy"
fordnatics
Recently, Jeffrey Engel wrote:
> I haven't a clue about the '94+ Mustangs, but the Mathis book says
> the T'bird arms are 13 3/4" (3/4" longer) than the Mustang control
> arms.
>
> Has anyone tried using them on a Mustang? How did they work?
I've tried them, and measured them. I don't know where Mathis got his numbers,
'cause they're wrong. The T-Bird arms are closer to 1.25" longer. That's
really too much extra track for most setups to deal with, either alignment-
wise or tire/fender clearance-wise. On the other hand, the extra track makes a
very noticeable difference in front end grip.
31 Jan 1997
[email protected]
fordnatics
Last fall. I fabricated some adjustable tie-rod ends for my '86 Mustang and
have been meaning to do this write-up for a while.
There are drawings and a descriptions of how to make these in Mathis' "Mustang
Performance Handbook 2". I used that for a starting place. He specs 7/8" OD,
.188" wall, 4130N tubing, a machineable CrMo steel, for the sleeves. None of
small local steel suppliers carried it so that left me calling the larger
industrial suppliers of tubing. Their price schedules stop at 20' lengths,
meaning that 1' cost the same a 20'. That left me with a 1' piece for $160.
No thanks. Instead, I decided to get a 1" OD piece of mild steel rod for $7. I
figured the extra thickness would make up for any loss of strength from not
using 4130N. The both the Griggs and Baer Racing kit use aluminum so this is
probably overkill but I'm more comfortable with overkill than marginally
strong enough. After I was finished, a friend told me that Aircraft Spruce
sells 4130N tubing in small quantities.
The fact that I had bought rod instead of tubing would require an extra step.
Obviously, that would mean boring out the center. So, I went in after work one
night and borrowed a lathe for a few hours. The tie-rod end is a 9/16-18
thread while the Heim joint end is a 5/8-18 thread. So, first I drilled out
entire rod for 33/64" and then went back and counter drilled the outer end for
37/64" hole 1" deep.
Tapping the outer end was easy since it isn't very deep. I simply used a 5/8-
18 bottoming tap and ran it in. On the other hand, the inner threads needed to
go almost 3" deep. This meant that a standard length tap would not reach the
bottom. So, I bought long tap from Rutland Tool (a great place to buy machine
tools). This didn't quite work either since its shaft expanded immediately
above the cutting threads. I had to take a bench grinder to my brand new tap
and reduce its shaft to an appropriate diameter.
Next, I used a milling machine to cut two flats on the inner end. This is so I
can get a 15/16" wrench. Otherwise, there would be no way to remove the sleeve
once it was in place.
Now came the part I was most worried about. The steering arms on the spindles
needed to be drilled and reamed out. The stock tie-rod ends use a tapered stud
where I used a bolt. It is critical that the clearance between the bolt and
hole be very tight. Most people recommend <.005". The AN10 bolts I used have a
spec of .620/.624 min/max OD First, I used a 39/64" drill to get close then, a
.6240" reamer to make the final cut. When all was said and done that gave me
.002-.003 of clearance. A .6220" reamer would have been even better but that's
all right. That was it for the machining.
Mathis specifies Aurora PRM-10T spherical rod ends. Frey Racing, a local race
shop, didn't have those in stock but had some AM-10T. We looked it up and the
only difference was that the AM-10T didn't have a stainless steel inner race.
Since I didn't feeling like waiting for an order, I picked up the AM-10Ts.
Either of these will run around $50/each. While I was there, I picked up a
pack of Coleman spacers (part #808-900) for $9.
At this point, I wasn't sure what length bolt to use. Instead of guessing, I
used a cheap grade 8 bolt temporarily. After all the bumpsteer measurements
were done, I bought two AN10-27 bolts from Coast Fabrication (714) 842-2602.
BTW, these guys are really good for AN and NAS fasteners.
I was doing this along with changing my front ball joints so my suspension was
already apart. I temporarily reassembled everything without the springs in
place. Both Herb Adams and Carroll Smith have good descriptions of how to
measure bumpsteer. I used an idea derived from these methods that Scott
Griffith came up with. I took a 50 caliper amo box with its lid tilted near
vertical and attached a magnetic stand for a dial indicator. The leading edge
of the stand was placed on the front edge of my brake rotor. Then, the dial
indicator was placed against the trailing edge. I recorded the dial indicator
reading at static ride height and then moved the suspension 1" into bump with
a floor jack. It was simply a matter of trying different spacer stacks to
minimize the toe change.
The obvious question is were there any improvements in handling. To be honest,
not much. That's primarily due to the fact that my previous setup ('90-'93
tie-rod ends), had very nearly the same outer pivot point that I have now. At
Sears Point, the track between turns 5 and 6 is pretty rough. My car tracked
slightly better through there. Bumpsteer is a subtle problem to start with and
the improvements are subtle too.
A couple of notes:
I haven't looked at my all notes yet so many of these dimensions are from
memory. That almost guarantees that some of them are wrong!
Also, I've got a couple of pictures of these on my web page:
http://www.stanford.edu/~kbrandt/mustang.html
18 Feb 1997
[email protected] (Jim Dingell at Performance Parts, Inc.)
fordnatics
The "original" 1995 Cobra "R" model wheel's part number was actually F5ZV-
1007-A. The wheels were designed by Australian wheel manufacturer A-Mold and
cast in Japan. Ford in actuality owns the design now. A-Mold continues to
produce the wheels for Ford Motorsport in the -M179 and -R58 offsets. JD
18 Feb 1997
Cole Reif
fordnatics
Report on installation of my Griggs subframes. First, thanks to all who sent
me comments when I asked for thoughts just before Christmas, and particularly
for the help with my "dumbo" weld and melt the convertible lines. It is all
together now and works great!
I called Griggs one Friday at 4pm and talked to Jon Gleason about doing the
install myself. He agreed it was feasable, said they do it in _1_ day, and
charge in the area of $700. I read him my card # and had a box on the
doorstep the following Monday!
To start I jacked the car as high as I could, super solid boxes under the
wheels will work, I used stands on rear axles and front control arms.
Measured frame to floor (checked first that floor was flat and level) per
section 47-04-20 of my '89 factory (Helms) manual, and consistently as I cut
and welded verified that the doors opened and closed _easily_. For comments
on subframes see Skod's BTPP Phase 5. For pictures of a Griggs type install
see Mathis', "Mustang Performance Handbook 2", ISBN 1-55788-202-9, on pages
29-31. Mathis shows subframes fabricated a bit different than the Griggs
units, but the concept is similiar.
2nd step is gut the interior, took me 6 hours to get seats, console, radio,
carpet, etc out.
Throughout, remember my convertible line experience and wrap your brake lines,
fuel lines, fuel vapor lines (nylon), etc with several layers of soaking wet
towels.
Mark location of lower subframe connectors, these are 2"x1" rectangular tube
with both ends closed, on the bottom of the subframes. Then remove the paint
from the area to be welded. Since I have a convertible there are plates from
the rocker panel braces pop riveted to the subs in these areas - 1st
annoyance! So clean up the edges of subs-to-plates and weld them on, then
grind off the rivets so the connectors lay flat against them and mark areas of
connectors to be welded. Paint connectors in unwelded areas and use 3M weld
thru on areas to weld. Weld the bejeezus out of it all. After welding each
side (on your back and collecting any sparks on your belly), take a break to
stand up, take advantage of the heating of the floor pan, and scrape of the
sound insullation in the drivers and rear seat footwells.
Clean of the rear bulkhead, this is the back of the rear footwells, and weld a
reinforcement brace flat onto the bulkhead. After the sound insulation is off
the front seat footwells you can see the spot welds for the subframes. The
2"x2" square tube lays into the front subs and buts to the rear bulkhead, to
get there you cut a trough through the floor pan and lay the tube in and weld
it up. I found that to locate the exact inner edges of the subs, I could cut
1.5" squares out with a die grinder and cutoff wheel, then mark lines and cut
with a recip saw (Cut Saw, Sawzall, etc). Mathis shows the cuts done with a
torch, the guy must have been a glutton for welding up a sloppy cut, I liked
the precise edge the cut saw gave me.
Lots of painting and stuff and reinstall of interior, all told it took me 5
days, could probably do another in 3. I used my Hobart Handler 120, C25
(75%CO2, 25%argon), 0.024" wire, voltage levels 1 &2, wire feed from 1 to 4.
The metal thickness varies greatly, the subs are pretty heavy, #2 voltage, 3.5
wire feed, the floor pan is pretty thick, #1 V and 1.5 wirefeed when chasing
"holes" : ) oops....
This is a superb stiffness increase with the 2" sq inside and the 1x2
underneath. The weight added by all of this is about 25#. My car
(convertible) was a bit tweaked (yeahh, Skod warned me in phase 5, "do
subframe connectors _before_ you do R tires" but did I listen . . . noooo) so
I put a house jack under the lower subs and "adjusted" the frame before
welding 'till the doors once again opened/shut easily.
As car projects go not a bad one to do, and I got to play with my new welder,
which paid for itself with this one project!
21 Feb 1997
Chuck Fry
fordnatics
>[email protected] (Ed Mulligan)
>I'm getting frustrated with the front end alignment on my 1992 LX5.0 hatch
>Mustang. 76K miles, suspension is as the factory made it. It has done this
>since day one. I've had it aligned by different shops, both dealer and
>independent. It consistently wears the inner 1inch of the front tires much
>faster than the rest of the tire - I can see it happening in 6000 miles on
>my new tires.
In 1990 the front end alignment specs were changed on Mustangs. The new specs
call out a degree or so of negative camber, which causes excessive wear on the
inside of the front tires when driven on highways.
A very real contributing factor is the Fox chassis's lack of Ackermann in the
steering. 100% Ackermann causes the inside front wheel to turn more sharply
than the outside front, so that the paths of the two tires describe the same
radius. This is ideal for minimizing tire wear and maximizing traction in
low-speed maneuvering on the street.
Larger slip angles complicate this discussion. Racers dispute how much
Ackermann is enough, with some believing in zero (parallel steer) and others
adjusting this at the track til they find the optimum setting. I won't get
into this argument here; see Carroll Smith's excellent "Engineer To Win" for
specifics.
By some accounts the Fox steering setup has negative Ackermann -- that is, the
inside front wheel turns *less* sharply than the outside front, pointing to
the outside of the turn. This is an unfortunate fault of the front-steer
geometry. And when combined with negative camber, it tends to cause excess
wear on the inside of the tire, as the lightly loaded inside front is dragged
across the pavement. Reducing the negative camber will help spread the wear
across the tread, but doesn't really solve the problem.
There are a couple of common approaches to getting more Ackermann in a front-
steer chassis. One is to move the steering rack rearward in the chassis.
Another complementary approach moves the outer end of the A-arms forward,
which increases caster as well. A third is to bend the spindle's steering arm
further outward, but the brake rotor limits the amount of movement.
To move the rack rearward, replace the rubber bushings that mount the steering
rack with plastic or aluminum bushings, and mount the rack flush against the
K-member. For more Ackermann, mill about 1/4" off the rack mount ears, so
that the ears are flush with the body of the rack, which then rests against
the K-member.
The Griggs Racing modified (and tubular) K-members relocate the pivot axis of
the A-arms, bringing the outer end forward. I hope to get my hands on one
soon.
Bending the spindles is not recommended, unless you know a good heat-treating
specialist. The act of heating the spindles to bend them ruins the factory
heat treatment, and so this has to be redone. The bending is also very
precise work.
Speaking of steering geometry, I have heard from someone who should know that
the steering rack in Fox Mustangs does not actually mount level --one mount is
higher than the other, due to compromises for manufacturing reasons. So if
you want to get picky about bump steer, you'll need to take this into account.
I don't know if this applies to the SN95 Mustangs too. -- Chuck
21 Feb 1997
Teddy Chen
fordnatics
> The shop
> recommended a device that fits on the strut and allows increased camber
> adjustment. This part replaces the top strut bolt and does the
> equivilent of slotting/elongating the strut/spindle holes. A bolt with
> a slightly smaller OD replaces the top strut bolt along with some other
> fanglage (sorry kp) that alows you do dial in some additional camber.
if i understand you right, you are talking about replacing the top strut-to-
spindle bolt. am i right?
my reaction to this device is: run away!
those bolts are under a hell of a lot of load, which is why ford made them so
beefy in the first place. even with mine reefed down to 200 lb-ft, they still
shift in the strut mounting bracket holes (which are slotted) after a day at
the track. i'm going to be fixing that shift soon, but the point is that
there's enough force in there to make a 200 lb-ft torqued bolt (loaded only in
shear) shift.
maybe if you're just driving the car around on the street, it's ok. but i
wouldn't want that thing on my car at the track.
> The tires do not wear out prematurely on the insides any
> longer, but the handling got worse. It's a shame that we have to choose
> between good handling and good highway tire wear on a Mustang but it's
> something we all unfortunately have to live with. From what I hear,
> using the SN95 spindles help this situation somewhat, but then you have
> to go to 5-lugs. The toe was set to 1/16 inch positive I believe
> (toe-in).
one of the main causes of the inner edge wear is the Mustang's poor Ackerman
steering characteristics. in a corner, the inside tire doesn't turn into the
corner enough, and ends up fighting the outside tire.
the SN95 spindles have relocated steering arms which improve the Ackerman to
some extent. milling the steering rack mounting bosses 1/4" will help, too.
23 Feb 1997
Jeffrey Engel
fordnatics
Some time ago I got tired of my teensie little 10" front disk brakes. Using
Mathis' book as a guide - yes, I know - I installed the 11" brakes and
spindles from an '83 Lincoln.
Everything went pretty much as planned until I tried to put the rotors onto
the spindles. The control arm hits the inside of the rotor. A couple of
options present themselves:
1. Assume something is assembled wrong.
Very possible. Everything except the control arm and fasteners is new. The
bushing to adapt the Mustang ball joint to the Lincoln spindle spaces the two
apart quite a ways. It was difficult to get the cotter pin into the top of
the ball joint.
2. Reform the end of the control arm.
My blacksmithing skills are nothing to write home about. I also would HATE to
weaken my control arm.
3. Machine the inside of the rotor so the control arm clears.
This seems to have the least negatives: cost, possibly the pad will hang over
the inside edge.
Does anyone have some experience with this setup? Any other ideas?
26 Feb 1997
"Theodore A. Chen"
fordnatics
>In preparation for driving in some open track events later this summer,
>I'm considering repacking the bearings on my (mostly stock) '94 Cobra
>with some good high temp synthetic grease. As I have not done this kind
>of service before, I was wondering how difficult a job it is to do. Will
>I need a hub puller? Is the bearing a press-fit into the hub? If so, do
>you clean and re-pack while still in the hub? How do you determine a
>correctly adjusted hub / bearing? What is the best lube for the job?
well, according to ford, the hubs are not user-serviceable and are to be
replaced "when necessary." the races are ground directly into the hub forging
itself, and once the bearings go away, that's it for the hub. so ford's right
in that respect, but you can still take them apart and repack them. get some
picks (my set was $7 at auto parts club) and use them to remove the expanding
c-clip that holds the two halves of the hub section together. watch out -
there are a lot of balls in there, and you don't want to lose any of them.
you can get at the outboard race and ball cage this way.
the inboard race and ball cage are another story. you have to remove the seal
to get at them, and according to skod, it's a unique part - no spares
available. in other words, trash this seal and you'll be buying a new one.
after trying for a few minutes to remove the seal, i decided to skip it. i
settled for injecting a lot of grease with a needle to force out the old
grease, and then sucking up some of the excess grease.
assembly, as they say, is the reverse of disassembly. there's no adjustment.
if they go out of adjustment, that's because the bearings or races are worn,
and you replace them. just like shimano's cartridge bearing bottom brackets
(for bicycles of the human-powered variety).
for grease, i'm using Mobil 1 synthetic. other people like redline CV-2,
particularly because it has moly in it (that's your last line of defense if
the grease melts).
you don't need a hub puller. all you need is a 35mm (note that i said 35, not
36, although people have been using 36 successfully) socket and a _big_
breaker bar. the 35 mm pack nut is supposed to be torqued to 250-300 lb-ft,
and it will take more than that to break it loose. your car may shift if it's
not properly supported, so do yourself a favor and make sure the wheels are
chocked, the parking brake is set, and the car is well supported on
jackstands.
note: when you remove the calipers (in order to remove the rotors in order to
remove the hub), do yourself a favor and replace the c-clip on the guide pin.
at the very least, make sure it seats properly. if the c-clip gets lost, the
guide pin will slide out until it starts hitting the spokes of the wheel. if
you're unlucky, the wheel will rip the pin out, causing the caliper to pop up
and do all sorts of nasty things to the caliper. this is the voice of
experience speaking.
>Secondly, I'm considering adding some caster / camber plates to give me
>more
>favorable alignment settings at the track. What would be a good setting
>to shoot for?
as much caster as you can get, as much negative camber as you can get, zero
toe to 1/4" toe-out.
>Do most caster/camber plates give you the same range of adjustment?
yes. CCM camber plates are a favorite among trackies. true, their
adjustability is limited, but you're going to be maxing out the caster and
camber anyway. and simplicity is a virtue in this case (fewer things to
break).
>If I
>change camber settings the toe-in setting
>will also have to change right? How would someone do this at the track?
the toe does change, but not a lot. i don't worry about it at all (maybe i
should). if you want to adjust the toe, you can figure out how much to turn
the inner tie rod to produce a 1/16" change in toe. then just do that when you
change camber settings.
01 Mar 1997
Teddy Chen
fordnatics
> Also, I hear the 90's and up have larger wheel
> wells. Is this correct?
yup, the leading edge of the front wheel openings have been trimmed back.
> Griggs Frame Kit
> Maier Racing Strut Brace
both good stuff.
> Central Coast 2 point G-Load Brace (maybe a KB 4 point)
i don't have a g-load brace, but everybody seems to think KB 4point is the way
to go.
> Eibach Street Rate Prog. Springs
> Koni Struts and Shocks
> Urethane Swaybar and Strut Mounts
> Griggs Modified Front K-Member
the best thing since sliced bread, according to skod.
> Caster/Camber Plates (no company yet)
CCM.
> Griggs Adjustable Height Arms
> HD LTD. Police Upper Arms
whoa, boy. all that money and stuff and you're going to stick with the 4-link
rear suspension? replace it with the griggs torque arm and panhard rod setup.
you'll need it if you want to put your 550 hp to the ground.
> Offset Drilled Aluminum Bushings
steering rack bushings, i assume. hold off on these until you know what the
bumpsteer measurement is. you'll want to add this to your list:
Adjustable tie rod ends
then you can tune out some of the bumpsteer.
> Baer 13"/12" (what about these 13-1/2"/13"'s I am hearing about?)
go with the M-2300-K brake kit. there's a lot of bang for the buck, and you
get the SN95 spindles and new axleshafts to boot. you'll have to go 5 lug,
but this is no big deal if you were buying wheels anyway.
you don't need crossdrilled fancy-shmancy rotors, in case that occurred to
you. braided steel brake lines are an excellent investment, though.
> ROH 17"/9"'s with some BF Goodrich Comp TA's
i take it you mean 17x9. how about Cobra R 17x9 wheels instead? they're
cheaper, for one thing.
> I am not really that concerned with price. I am more interested in building
> a super handling Mustang, which will give me control over the 550+ hp I plan
> to drop in. Well, for now, that is all I can think of. I probably missed a
> whole crapload of stuff, as I am very green to the subject of Mustang/Car
> handling and suspension. Let me know what you think...
actually, your list is pretty complete. you should consider adding a roll
bar/cage to your list, too.
04 Mar 1997
Robert Whitley
fordnatics
>Does anyone know of the spring rates and sway bar diameter of a 93 Cobra?
How does
>this compare to an 89 LX 5.0? I would like the numbers just so I can compare
>these to aftermarket springs and sway bars, in case I can get something
similar
>cheaper than the original Ford part.
>
93 Cobra
front springs 425-530 (variable: normal ride height, full jounce)
rear springs 160 (constant)
front bar 1.125
rear bar 0.83
93 Cobra R
front springs 750-850 (variable: normal ride height, full jounce)
rear springs 240-260 (variable: normal ride height, full jounce)
front bar 1.13
rear bar 0.83
89 LX
front springs 425-530 (variable: normal ride height, full jounce)
rear springs 200-300 (variable)
front bar 1.13
rear bar 0.83
04 Mar 1997
Chuck Fry
fordnatics
been there, done that. the problem is that on my CCM plates, the studs aren't
quite parallel, and it takes a bit of force to get the plates on.
That's not an issue with my set. If I were you, I'd either *make* the studs
parallel, or get CCM to do so.
the other problem is that you'd have to remove the nut on the strut shaft, and
i find it a pain to remove it and then tighten it back down (you have to hold
the shaft with pliers while using a combination wrench on the nut, and there's
a lot of back-and-forth required).
The Koni struts I'm using have flats cut in the top of the shaft for a 10 mm
open end wrench, so again this isn't an issue with my car.
i've never tried to measure the toe change as a result of changing camber
settings. i wouldn't expect it to be major. how much of a change in toe are
you seeing?
To be honest I haven't measured it either. Remind me to check the next time I
set the car up for the track.
The front-steer configuration means that making camber more negative (tipping
the tops of the wheels in towards the car) will tend to toe the front wheels
out; making camber less negative tends to toe them in.
04 Mar 1997
Teddy Chen
fordnatics
> the CCM units actually do offer some camber adjustment themselves:
> a race setting and a street setting. theoretically, you could adjust
> the camber without disturbing the position of the strut mounting plate
> (and thus the camber adjustment of the plate), but in practice i find
> that impossible to do, so i just leave them in the race setting and
> slam the plates all the way in for the track, all the way out for the
> street.
>
> I'll admit it's pretty tricky to do this without disturbing the mounting
> plate. But I routinely switch between the street and track holes. The
> trick is to jack up the front end just until the struts drop out of the
> camber plate. It really doesn't take that long, maybe 15 minutes tops.
> Of course then you have to redo the toe...
been there, done that. the problem is that on my CCM plates, the studs aren't
quite parallel, and it takes a bit of force to get the plates on. it was
worse before, but i used a hammer to more or less align the studs properly.
but it's still rather difficult to put the plates back on without disturbing
the alignment, and once the lower plate shifts, the alignment is gone.
the other problem is that you'd have to remove the nut on the strut shaft, and
i find it a pain to remove it and then tighten it back down (you have to hold
the shaft with pliers while using a combination wrench on the nut, and there's
a lot of back-and-forth required).
it's easier for me to loosen the three mounting plate nuts and use a crowbar
(or a really big screwdriver) to move the plates. that takes me about two
minutes, and i do it when i'm jacking up the car to change tires at the track.
the front suspension gets taken apart on a fairly regular basis, and my car
doesn't hold an alignment, anyway, so i just max out the camber and don't
worry about it.
i've never tried to measure the toe change as a result of changing camber
settings. i wouldn't expect it to be major. how much of a change in toe are
you seeing?
18 Mar 1997
George Najarian
fordnatics
As promised, here is a summary of the AFS Cobra 'R' Replicas I received last
night.
First, I want to commend AFS for their customer service. They kept me informed
of the status of their shipment, and I never felt like they were 'pulling the
wool over my eyes'.
Total cost - $695 + tax + $45 shipping (local). The box (!) weighed 105lbs.
Visual: The rims look the same as the 'R'. The markings are completely
different. A notable omission is the japanese certification mark 'jwl'
something that is cast next to the air hole. These rims have 17-9J and 1400lb
stamped on the insides of the spokes. There are no other external markings.
Measured values:
Weight 22lb
Rim width 9"
backspacing 6"
The dimensions and weight are identical with the Ford rim. Also, the machining
and color appear to be the same. There were cosmetic blemishes on the non-
visible parts of the rim (at least the 2 I have looked at so far).
26 Mar 1997
Teddy Chen
fordnatics
> Greetings. I've installed the M-2300-K brake conversion on my 1990 Mustang,
> with 17X9 wheels. But now extreme turns cause the front wheels to grind on
> the wheel wells. The rear fenders were rolled, but it's not really possible
> on the front. I've heard that there are limiters that you can install
> somewhere on the steering linkage that will stop you from turning the wheel
> too tight.
if the front wheels are rubbing the wheel wells, steering limiters aren't
really the answer. since you've got a '90 mustang, i'd bet the rubbing on the
wheelwells is at the leading edge of the wheel well. this edge was cut back
in '91-'93 mustangs for more clearance with the 16" wheels. i've got some
rubbing in that area on my '87.
i'd suggest flattening the fender lips up front and maybe pulling out the
leading edges of the wheelwells to try to increase clearance a bit.
if the front wheels are rubbing the control arms or k-member, then the
steering limiters will help. they do exist.
29 Mar 1997
Teddy Chen
fordnatics
> Does anyone have the recommended proceedure for
> opening up the hub.
the recommended procedure for opening up the hub is:
don't.
but you knew that.
> I had some mail from Scott Griffith, some time back,
> and can't seem to find it.
i've got it, but it's at home. i took apart my hubs and repacked them with
synthetic grease a while back, so i'll see if i can rehash:
> As I remember, he was using Dental type tools
> to pick at a seal, then a retaining ring, but be careful,
> because if you fudge up the seal you're fried, as there is
> no replacement.
the tools you need are picks. i used a set that i bought from auto parts club
for $7. had a straight pick, curved pick, hooked pick, right angled pick,
screwdriver, etc. you should be able to find picks at an auto parts store.
> Is the seal in question, the one that looks like a typical
> hub grease seal that faces the rotor, or is it the seal in the
> center of the bearing.
it looks like a typical hub grease seal, but it's on the inner side of the hub
if i remember right. i don't think there's a seal in the center of the hub.
> I plan on using Mobil 1 synthetic, and when I first installed
> the kit, I packed the the snout with grease and put on the
> dust cap per standard tapered roller bearing spec.
that's what skod uses, and that's what i used. skod says if it's good enough
for penske, it's good enough for us. if i didn't already have the mobil 1
grease, though, i'd probably have used redline CV2 (with the moly in it).
i don't understand what you mean about packing the snout with grease (it's
solid). you mean you just crammed grease into the area over the hub nut and
put the dust cap on? if you did that, that probably didn't help, but didn't
hurt either.
ok, first remove the hub with a 35mm socket and a big ol' breaker bar. be
careful, because with the composite nut torqued to 300 lb-ft, the car may
move.
the hub consists of two halves that are held together with an expanding
circlip inside them. the circlip has a channel section that is open toward its
outer circumference. the ends of the channels fit into grooves in the inner
circumference of the two halves. if you look at the inside of the hub (the
part that rides on the snout), you'll see the black circlip (i think you may
have thought it was a seal).
using the picks, lift the circlip out of the grooves. once you do that, the
wheel flange half of the hub will lift out with little effort. you'll see the
outer ball bearings. if i remember right, there's a plastic retainer. pull
it out and the bearings will come out easily. i don't remember a seal for the
outer bearings.
the other side is not so easy, because of that unique seal that you mentioned.
it's pretty large, and i tried to remove it, but the seal started to deform
and i decided not to mess with it. the seal is in there pretty tight. so, i
sucked out as much of the old grease with a needle as i could, and then pumped
in fresh grease.
not ideal, but i wasn't willing to risk messing up the seal and having to buy
a new hub. skod did remove the seal, but he made up some special tools.
seemed like too much effort for not much difference to me.
BTW, while you're doing this, check the hub immediately behind the wheel
flange. there's a thinwall section right next to where the races are
machined, and i've heard that the SN95 hub may crack here. as you can
imagine, separation of the wheel flange from the rest of the hub may have
severe consequences.
if there are any cracks, however small, replace the hub.
04 Apr 1997
technic
fordnatics
Carl Morris wrote:
>be stupid for "serious" track use, but I'm actually
>leaning toward the lighter duty "street" version.
>If I'm ever at the right place at the right time, I'll
>definitely take a couple of laps, but my real interest
>is drag racing and street performance. My exhaust
>is turned down right now, but I would prefer to keep
>the option of going back to stock type exhaust.
A good alternative for your situation is the Ford SVO/Global West Trac-Link
and lower control arms. You can find these in the Ford Motrosports SVO catalog
or direct from Global at 909-349-2090. I am in no way associated with them,
they just have ggod stuff.
The Trac-Link accomplishes the same goal as the Griggs torque arm, but you
leave the upper control arms in place and there is no problem running a full
rear exit exhaust system. The Trac-link plants the rear tires under
acceleration and prevents nose dive under braking just as described for the
Griggs arm so I won't repeat that here. You toss the quad shocks and brackets,
the pinion snubber and the differential weight (that huge chunk of cast iron
hanging under the pinion nose). This all weighs 20 pounds and the Trac-link 18
pounds so you save a net 2 pounds. You MUST keep the stock upper control arms.
You do NOT want to run anything stiffer than bone stock arms and bushings.
Otherwise you WILL experience suspension binding. Ford tested the product
before putting in the SVO vatalog under their name so you know that the
product works with the stock set-up very well.
If you can, I would diffintely put the Global West lower control arms also.
These too are offered in the Ford SVO catalog. They use a strong round steel
tube (basic engineering, round cross section tubing resists torque twisting
forces better than square cross section tubing. The only way to get an equal
amount of stiffness from square tubing is to significantly increase the wall
thickness and thus the weight) for the arms. Poly bushing at the axle location
points and aircraft spherical bushings at the body mount points. Why spherical
bushings instead of poly? For a car driven around corners (either street
driven or raod race) the control arms must be able to move in a twisting
plane. The distance between the axle and the car body is unequal in cornering.
The inside part of the body lifts away slightly and the outside is pushed down
slightly. Full poly bushings at both end bind the suspension, resisting this
twisting motion and resulting in poor handling. The only real solution is to
use a bearing that is spherical and allows as much rotation as is needed,
preventing any binding.
Used together, the Trac-link and lower arms from Global provide an excellent
solution for street driven cars. The rear end is solidly located, traction and
braking are dramatically improved, handling is improved with no binding
problems and you can run your full cat back exhaust with no interferrence
problems. Should work great for your application.
08 Apr 1997
Teddy Chen
fordnatics
> If you can, I would diffintely put the Global West lower control arms
> also. These too are offered in the Ford SVO catalog. They use a strong
> round steel tube (basic engineering, round cross section tubing resists
> torque twisting forces better than square cross section tubing. The only
> way to get an equal amount of stiffness from square tubing is to
> significantly increase the wall thickness and thus the weight) for the
> arms. Poly bushing at the axle location points and aircraft spherical
> bushings at the body mount points. Why spherical bushings instead of
> poly? For a car driven around corners (either street driven or raod race)
> the control arms must be able to move in a twisting plane. The distance
> between the axle and the car body is unequal in cornering. The inside
> part of the body lifts away slightly and the outside is pushed down
> slightly. Full poly bushings at both end bind the suspension, resisting
> this twisting motion and resulting in poor handling. The only real
> solution is to use a bearing that is spherical and allows as much
> rotation as is needed, preventing any binding.
and because the lower control arms have spherical bearings in them, they never
see any twisting force. so the round cross-section you cite has no advantage.
the lower control arms will be stressed in tension or compression (as the rear
axle tries to move forward or backward), and in bending (from the rear
springs), but not in torsion.
i don't consider the round cross-section to be an advantage. a better design
would be a rectangular cross-section or an I-beam. if you look at the Griggs
lower control arms, you'll see that their shape is pretty clearly intended to
resist bending loads from the springs, but not torsion.
i agree with what you say about needing to accommodate body roll and the
spherical bearings, but stock lower control arms with poly bushings at both
ends also work well. the stock control arms are made of stamped steel formed
in a channel section, and has enough torsional compliance to accommodate the
body roll.
tubular control arms, as you said, are very strong in torsion. they have
essentially zero torsional compliance and with poly bushings, you get a lot of
roll bind.
> Used together, the Trac-link and lower arms from Global provide an
> excellent solution for street driven cars. The rear end is solidly
> located, traction and braking are dramatically improved, handling is
> improved with no binding problems and you can run your full cat back
> exhaust with no interferrence problems. Should work great for your
> application.
hmm. i know some people who have had that setup and discarded it. i don't
think you can add another link to the suspension without increasing bind. the
question is whether the benefit of adding that new link is worth the added
bind.
i've been thinking about this - people add stuff that increases suspension
bind and makes them go slower, but they love the change and think it makes
them go faster. i suspect that this is due to the change in "feel". the
suspension feels tighter and more predictable, and that's what they pick up
on. but some of that slop they just got rid of was actually compliance that
helped the suspension keep the tires on the ground, and they end up with a car
that oversteers more and is slower out of the corners. they don't realize
that it's slower, but they know that it "feels better" because the rear end
isn't moving around all over the place any more. just because it's slop
doesn't mean getting rid of it will make the car faster.
here's an analogy. i had some bridgestone potenza RE71RAZ race tires, and
then i had some BFG Comp T/A R1s. the RE71s were vague and mushy as hell, and
i could never tell what they were doing. by contrast, the R1s felt razor
sharp, and communicated every bump, twist, and slip to the steering wheel.
they operated at low slip angles, and they felt much more precise. at Laguna
Seca a couple of months ago, i flatspotted the R1s and put my old RE71s back
on, and discovered that i was faster on the RE71s, even though the R1s "felt
better". (i actually discovered this before, but at the time i thought it was
because i didn't have tire pressures dialed in properly.)
i recently changed my setup from upper control arms with poly bushings at both
ends (previous owner put them on) to SVO uppers with rubber bushings, and poly
bushings in the differential. although the car feels a little sloppier, it
doesn't oversteer as much and it hooks up better in the corners. i'm
convinced that this change was for the better, even though i have more "slop".
i still continue to believe that poly bushings in 6 of the 8 locations in the
rear provide the best bang for the buck.
06 May 1997
Todd Glidden
fordnatics
About a month ago I posted a question about a wheel limiter that would keep my
front wheels from rubbing on hard turns, ever since the M-2300-K brakes were
installed. Many thanks to all who responded. Several emailed me, asking to
be notified of the results since they had the same problem.
Okay, I went to the local Ford dealer today, and they sold me part number
N804842-S, "Washer, AX 26". They are two white polyeurethane "C" clips, that
go on the linkage before the tie-rod ends. From the 1990 F (Mustang) shop
manual, page 14448, it calls it a "Travel Restrictor used on GT and handling
packages".
I haven't put them on yet, and probably won't have time for a while. I don't
know if they will work, but at $2, what the heck! Just be sure to ask the
dealer to photocopy the front suspension page from the shop manual, so you
know where to put the clips. When I get time, I'll see if the leading edge of
the front wheel wells can be moved out; when I get new tires, I'll move down
from 255's to 245's in the front.
19 May 1997
[email protected]
Ford
On May 19, turbinepower wrote:
> There has been so much kicked around these days about the various brake
> options for Fox cars that it is becoming confusing, so I'll try to ask about
> them in an organized format so that we can all get it straight (including
> myself).
>
> true or false: The common rear disc conversions from Ford Motorsports and
> Stainless Steel Brakes are Thunderbird Turbo Coupe brakes that have been
> adapted to retain the stock rear track width of the Fox Muxtangs.
True. They use an offset caliper bracket that locates the T-bird Turbo
Coupe 45mm caliper 3/4" inboard, so that the rotor can meet up with
the stock-width axle.
> Are the above kits available with 5-lug rotors but still able to keep the
> stock rear track width?
No- but rotors *are* available that will allow such a thing, if you
are willing to spend some time crawling through the parts catalogs
(there was some '90 or '91 Lincoln application with those calipers on
a 5-lug, if I remember correctly). Your problem, of course, is then to
find 5-lug axleshafts in the stock width. It can be done- it just
isn't, very often, since the change of wheels from 4-lug to 5-lug
offers the opportunity to adapt around the track change with less
drama.
> Are the rotors solid or vented?
Vented. And therein lise one of the great curiosities in the history
of Ford braking system design. The sorta-semi-bad news is that they
are cast with directionally vented internal finning: but in its
infinite wisdom Ford only ever cast *left-side* rotors (I believe that
they were lefts- it's been a few years since I held these in my
hands). There is only a single part number for both sides of the Turbo
Coupe and the '93 Cobra. So your brake temps in track use will run
about 200degF hotter on one side than the other. Some of the
aftermarket companies did do non-directional rotors for this
application (Autospcialty comes to mind), but Ford apparently felt
compelled to do this one strangely just to play with our minds...
Don't ask me why this is: it just _is_. Nobody I've ever talked to at
Ford could explain it, any more than they could explain why the Fox
K-member mounts the rack with the passenger's side 3/8" lower than the
driver's side, and screws up the bump steer so badly... Don't get me
started.
> What is their diameter?
10.16" OD x .945 thick.
> __________________________________________________________________
>
> Regarding SVO/Lincoln/Saleen REAR brakes:
>
> true or false: These are the ones that increase rear track width by 3/4" or
>so
The commonly available 5-lug axle shafts do increase the track width,
yes, since they originally came from the '83-83 Lincoln Continental.
SVO just pulled the Continental pieces off the shelf to make the SVO
Mustang. The rotors and calipers are set up to use a cheap, 1-piece
flat stamped bracket. If you were willing to make an offest bracket,
these calipers could also be used on a stock track width axle- but
you're on your own on the bracket. I personally used SVO Mustang
caliper brackets, modified them, and welded them to my axle housing to
allow me to run the odd combinations I wanted.
These calipers are the 54mm Varga calipers. They are also no longer in
production through regular Ford sources, although I believe that
Stainless Steel Brakes still imports fresh casting from the foundry in
Barzil for their own needs.
> t or f: They also have bigger calipers and rotors
True- 54mm versus 45mm for the caliper bore. The pad area is at least
50% greater. The rotors are 10.66" OD and .946" thick. And they are true
directional rotors, with differently canted fins for the right and
left side, and different part numbers.
> _____________________________________________________________________
>
> Some general questions on other brakes:
>
> Are Cobra brakes also PBR/Corvette brakes?
Yes, and no, depending on the year. The '93 Cobra got a wierdball
orphan version of the Fox brakes (3/4" greater offset on the rotor hat
section, but still iron 66mm calipers on an 10.91" x 1.06" rotor). The
'93 Cobra R got the PBR setup with 13" x 1.18" rotors (basically, it
got preproduction 'SN95 spindles, hubs, wheels, and so on). '94-up
Cobras and R's alike got the Corvette-like PBR pieces up front, since
they are a trivial bolt-on on the SN95 spindle. They get the
non-Corvette, strange little 38mm SN95 calipers out back, though. The
base SN95s use a teeny little thin solid rotor (something like 10" x
.375" thick), and the R's use a thicker, vented rotor with thinner
pads, as I understand it. I'm talking through my hat on this one,
though, since I've only ever held the base model parts in my hand- so
someone should correct me if I'm wrong.
> Or is it Cobra R brakes that are PBR/Corvette stuff?
Essentially, yes, for the '93 and later Rs. The caliper differs in
various details, such as the cast-in Cobra logo and some of the
reinforcing detail. The anchor ring is drilled for 14mm hardware for
the Corvette variant, and 12mm for the Ford. But you can use the same
slider pin, pistons, rebuild kits, and so on. If you graunch a caliper
on your Cobra brake setup at the track, truck over to a Chevy dealer
and just snag a replacement- it'll drop right onto your existing
anchor ring, and the brake line will bolt right up.
> I thought Baer Claws are PBR/Corvette brakes, but every now and then I read
> something that implies otherwise.
Hal Baer has sold about ninety different variants of his Baer Claws.
The vast majority have been PBRs. Some of the other really high-dollar
variants have used Brembo and Alcon 4-pots, which are a wholly
different kettle of fish. The biggest thing about Baer Claws in
general is that they were designed to work with a modified Fox
spindle. The Motorsport M-2300K kit includes SN95 spindles and hubs.
> Oh yeah, is it possible to have 12" instead of 13" rotors in a PBR/Corvette
> deal?
Sure. I did as 12.25" setup with the PBRs for a couple of seasons, to
protect my investment in a set of 16" wheels. It just takes some
design time, and the appropriate spindle modifications to relocate the
caliper radially. Baer also sells a 12"x1.1" PBR setup right off the
shelf, since that is the size required by the SCCA A-Sedan rules.
I'm popping last year's 13"x1.1" PBR setup on the front of Cindy's new
car. But I didn't have any hardware in hand for the rear that still
had a good, streetable parking brake mechanism. Since she commutes
into San Francisco every day, she finds a working parking brake to be
non-optional... So, never being one to shrink from an opportunity to
do something Sick with a new braking setup, I'm building up a
Corvette/PBR rear setup using the '88 Vette 40mm single-piston sliders
<<<>>>
mechanism, so I'll be able to adapt SVO Mustang parking brake cables
without too much pain, I think...
I do not know why Ford went with the little wierdball caliper on the
rear of the SN95s, instead of just using the obvious Corvette or
Camaro caliper that GM had already cost reduced for them. There's no
answer for that question, either.
20 May 1997
[email protected]
[email protected]
On May 19, Dave Williams wrote:
> Scott's motor had Ozzy Osbourne, Black Sabbath, ZZ Top, and Kiss.
> Dang thang oughta be able to sing "Shout It Out Loud" all by itself by
> now...
That's pretty amusing, because when it went into the car what was
playing was a good mix of Human Sexual Response ("I Wanna Be Your
Cow", especially), Wall of Voodoo, Primus, and a tad bit of good old
vintage Gang of Four, with some 1981-era Blue Nile mixed in for
mellowage.. It's gonna be one *confused* hunk o' iron. I'm not sure
that it knows quite what it's got itself into here, but on the
offchance that the Windzilla might actually have functioning ears, I'm
certain that it is getting pretty worried at the change of musical
pace right now.
The fit with the Canton roadrace pan and the 1" engine setback is what
you could call "snug". The pan will just barely clear the power
steering ram fluid line once the motor is in the car- but it just flat
will *not* clear it when you are putting it in and wrestling with it
to get the tranny mounted up. Crunch. Scratch one rack. Broke the boss
off, right flush with the ram body. No biggie, there are spares
readily available. But now I know that I should machine the rack mount
bushings to install the rack lower (by about 3/8-1/2") on the Griggs
tubular K-member. You'd have to do the exact same thing on a stock or
modified stock k-member, so beware if you are contemplating this
particular setup (1" setback, Canton pan). I also need to fabricate a
steering coupler shaft that is about 1/4" longer to make everything
match up properly with the lowered rack. No prob, the old one with the
Borgeson u-joints everywhere can just go on Cindy's car.
If the boss broke off that easily (and it did go _very_ easily- it
didn't even scratch the flat black paint that Dave shot the pan with,
nor did it bend the 8mm hard line!), my belief is that it was already
cracked. There was no leakage, but I can guarantee that I'll be
crack-checking that casting on the replacement. Just a word to the
wary: that rack was from an '87 GT parts car, and had over 100Kmiles
and a lot of track time on it. In the immortal words of Carroll Smith:
"There is no such thing as a part that can be bolted onto a race car
and then safely forgotten".
Had tons of fun working on the blue car (Cindy's new-to-us '89 5.0 LX)
on Saturday. It needed a fuel pump and a heater core, which is part
of the reason that we got it as such a bargain. I _love_ doing heater
cores on Foxes. Just freakin' _love_ it. Proper music for a Fox heater
core replacement has to be either the Dead Kennedys doing "Too Drunk
To F*ck", or Dean Martin doing "That's Amore'". Just one or the other
of those two songs according to your taste, played over and over and
OVER again, cranked up until the power amp is clipping, for the
duration of the project. Basically, this musical selection is simply
to underscore the fact that it feels so good when you *stop*...
The effort to get the red car ready for Laguna at the end of the month
has now been officially abandoned- when I find myself going to sleep
on the creeper, I know I've gone too far. The goal now is to get in
some good testing in July, and debut the car at Mini Nats on Labor Day
weekend. I'll spend the next few days while the red car is still off
at the exhaust shop plopping the 13" PBR/12" Corvette brake setup on
the blue car, so that we'll have something to drive at Laguna. Ahh,
the joys of prepping _two_ cars.
23 May 1997
Teddy Chen
Ford
> '94-up Cobras and R's alike got the Corvette-like PBR pieces up front, since
> they are a trivial bolt-on on the SN95 spindle. They get the
> non-Corvette, strange little 38mm SN95 calipers out back, though. The
> base SN95s use a teeny little thin solid rotor (something like 10" x
> .375" thick), and the R's use a thicker, vented rotor with thinner
> pads, as I understand it. I'm talking through my hat on this one,
> though, since I've only ever held the base model parts in my hand- so
> someone should correct me if I'm wrong.
never looked at the base SN95 rears, but i'll look next time. the '94+ Cobra
and '95 Cobra R have an 11.65" x 0.75" vented rear rotor. i didn't check to
see if the rotor was directional or not, but i vaguely recall that there were
left and right rotors so i assume the rotor is directional.
yes, they use thinner pads. base SN95s are D-627, and the Cobra/R gets D-
627A. some D-627 pads will work if they're thin (or worn) enough.
> If you graunch a caliper
> on your Cobra brake setup at the track, truck over to a Chevy dealer
> and just snag a replacement- it'll drop right onto your existing
> anchor ring, and the brake line will bolt right up.
yes. my car currently wears a Corvette PBR caliper on the left and
a Cobra PBR caliper on the right.
> So, never being one to shrink from an opportunity to
> do something Sick with a new braking setup, I'm building up a
> Corvette/PBR rear setup using the '88 Vette 40mm single-piston sliders
> on a 12" x .810" rotor. They have a forward-pull parking brake
> mechanism, so I'll be able to adapt SVO Mustang parking brake cables
> without too much pain, I think...
what about the Camaro rear PBR calipers? what size are the pistons?
this is something i'm going to change sometime, because the tiny little pads
just aren't cutting it right now and i'm tired of looking for good pads.
> I do not know why Ford went with the little wierdball caliper on the
> rear of the SN95s, instead of just using the obvious Corvette or
> Camaro caliper that GM had already cost reduced for them. There's no
> answer for that question, either.
probably had some existing requirements contract with the facility (Varga)
that made the caliper. not everything is driven by engineering.
27 May 1997
[email protected]
Ford
On May 24, Mike vanMeeteren wrote:
> I want to put 5 lug rotors up front.
> Anyways, I know that I have to swap the spindles. What spindles swap into
> an 89 LX? I'm assuming any of the 87-93 V8 Mustangs fit, but will spindles
> from, say a MarkVII or Lincoln continental fit?
Yes- but you probably won't care for the steering feel. The Lincoln
spindles have longer steering arms, which are a win for Ackerman but a
lose for the overall steering ratio. The steering will be noticeably
slower. I ran them for a little while, but couldn't stand the steering
feel. You might like it- but be aware. You would also need to get some
tapered spacers to adapt the larger ball-joint taper to the smaller
stud on your Fox balljoints.
> Once I have the spindles, where do I get 5 lug rotors? Is there a car that
> has the same rotor as the Mustang, except for 5 lug or is this an
> aftermarket rotor only deal.
Sure- the SVO Mustang, '82-83 Continental, the non-ABS Lincoln LSC...
Getting the front rotors is trivial. Just look up the SVO for the
part number. It'll drop right on your spindle, whether you use the 11"
Fox or the 11" Lincoln spindle.
> What about the calipers? Do the 4-cyl ones fit? I'm assuming not, so then
> does changing the caliper neccesitate a master cylinder swap as well?
I'd recommend that you do Carroll Smith's floatation test on those
calipers. Toss them in the nearest large body of water (after
carefully removing all traces of road spooge and brake fluid in an
appropriately environmentally-aware manner, of course...), and if they
float, *then* keep them. (;-)
You'll want to get the 28mm (1.125") master cylinder for the SVO
Mustang and non-ABS Lincoln LSC. You'll want to pick up some 73mm-bore
calipers from the same car, and you'll want to make sure that they
have steel pistons. Phenolic pistons are a crime against nature...
> BTW, Skod- are you still selling those spindles? I'm probably interested
> in them if you still have them.
There's one guy ahead of you who wants the whole wad. But if that
falls through, they're yours...
27 May 1997
[email protected]
Ford
On May 22, [email protected] wrote:
> I have an 85' Tbird TC I believe it to have 10inch front disk brakes.
> 87'-93' Fox frontsik brakes are 11 inches. Do I only need the Calipers and
> rotors (like Scott is selling)? Do I also need the 87'-93' spindles? All
> of these parts would add up to around $175, any hidden costs?
You'd also need to make up some spacers to adapt your struts to the
newer spindles. The older spindles have a much thicker mounting ear at
the joint between the spindle and strut. There is an ASCII text
diagram of the spacer that has been posted here many times, and that
can be made pretty easily with hand tools. You can find the diagram in
the archives, or contact Tom Stangler, its author, at
"[email protected]" to get a copy.
If you just go to the 11" 66mm Fox calipers, like the ones I am
selling, you can stay with your stock MC. If you choose to go to the
bigger 73MM Lincoln calipers, then you'd need an MC change. If you are
thinking about becoming a serious autocrosser, then you'll likely want
to go bigger on the calipers to be competitive- after all, I believe
that this change bumps you out of stock class anyway, does it not? I
don't keep track of autox rules, so I don't know.
If you buy my rotors, I'll be sure to include some usable wheel
bearings. I just discovered yet another cache of Fox wheel bearings
under the parts washer.
Your 10" flex lines won't work on the 11" calipers. I do not believe
in selling used brake flex lines, especially if they have 100kmiles on
them and have lived out here in the California ozone. I will not allow
the ones from the blue car to be used on a car that will see track
duty, so replacing them is a hidden cost. I'd recommend either buying
fresh OEM ones or upgrading to braided lines, I'll send out the parts
list to do so to anyone who wants it...
02 Jun 1997 09:21:59 -0700
[email protected]
Ford
In his series of books on race car preparation, Carroll Smith wrote
that there was no such thing as a part that could be bolted onto a
racing car and then safely forgotten about. We got a chance to
experience that firsthand this weekend at Laguna.
The '86 GT that we've been running for many years is still down, with
the new motor going in as part of its 10th-season ground-up rebuild. A
few weeks ago, Cindy and I found a very nice blue '89 5.0 LX hatch
with 112K miles on it for a song, so we bought it with an eye towards
making it her wet-weather commute car and also as a backup track car.
I spent the last week thrashing a bit to transplant Cobra 5-lug brakes
on it (since I can't bring myself to drive Laguna with stock brakes!)
and do a decent track prep, and off to the track we went. Since it was
to be the car's first-ever track event, we put on full-depth, non-sticky
tires, and went out with the idea of giving it a slowly-increasing
shakedown cruise, just to see how it would behave.
I was busy with driving instruction duties on Saturday, and wasn't
planning on driving much. I was out as instructor in the passenger
seat of another car in the third session, when coming down to Turn 10,
I saw the blue car pulled over on driver's right against the Armco in
a safe place past the apex of Turn 10, and Cindy standing beside it,
giving me the British royal "parade wave" (cup hand, rotate wrist a
little bit, use free hand to demurely hold the pearls in place in the
decolletage, although the presence of all that Nomex and the absence
of any pearls did tend to reduce the impact of that last bit
somewhat under the circumstances...).
Hmm.
Next lap through, I saw that the hood was concave, instead of being
convex like a Fox Mustang hood should be. And it was partway open.
Hmm.
Next lap, I saw that the windshield was comprehensively shattered, and
that Cindy had stopped giving the parade wave and was busy sending
hand signals to the cornerworkers to ask how long was left in the
session.
Uh-oh.
When we all convened in the paddock at the end of the session, it
started becoming more clear what had happened. As she came out of the
bottom of the Corkscrew and into Turn 9, the hood latch had failed.
The safety catch held the hood down for just a brief second or two in
9 (she described the feeling as "like hitting a big gust of wind"),
and then BANG- the hood folded promptly up over the top of the car,
leaving her with a nice view of shattered glass and the number "95" on
the hood, upside down. She did a wonderful job of getting the car
under control, whoa'd down, and off the track to a safe place, given
that she had no forward visibility.
The hood was comprehensively trashed, of course, by its encounter with
Bernoulli's wonderful Effect at near triple-digit speeds. The
windshield was obviously a goner (what is it with Griffiths and
windshields at track events, anyway?). The plastic air inlet grille
was in toothpicks, and the underlying windshield wiper support/cowl
panel was comprehensively punched in across its full width, fender to
fender. The hood hinges were twisted aft, and the cowl firewall where
they bolt on was wracked. When the hood was lowered, it sat almost 2"
aft of where it ought to be. The roof had three nice deep creases in
it- one on each side where the hood stamping embossed it, and one
right in the middle where it just buckled in under the load. It was
wrinkled back about halfway to the hatch gap. Believe this: let your
hood get loose at track speeds, and it will _comprehensively_ commit
Urban Renewal on the front end and top of your car.
We did what any properly insane trackies would do under the
circumstances, of course. We dived for the toolbox, and grabbed the
ball-pein hammer and the other metal-moving tools. After all, the
paint was chipped already, and there was another track day to go!
About 10 minutes of work with the hammer and my beloved 24" Craftsman
screwbar, and the hood was once again vaguely hood-shaped and more or
less back in its normal place, sort of. This took place accompanied by
much merriment and derision on the part of the Porsche people
paddocked on the other side of the fence (there were many comments
about "Ford bodywork" while I was wailing on the hood with the
hammer).
The hood was wracked back into place and anchored down with a
tastefully-matched blue ratchet tiedown strap to the bumper supports.
A call to A-1 Glass in Salinas got us a new windshield delivered and
installed right at the track, and by the end of the day we were up and
ready to go for Sunday. I even made a humongous Band-Aid out of some
orange duct tape and a folded up paper towel (using a magic marker to
fake the ventiliation perfs), and stuck it on over the middle crease
in the roof just for amusement value. Any stock-car team would have
been right proud of us, I should think. Many thanks to Cindy, and to
club members Jerry Brown, Marty Udisches, Borys Senyk, Scott Hung, and
others who undoubtedly helped a lot and whom I've forgotten.
Sunday passed without any great drama. I got some good seat time out of
it, got a big smile out of how much fun it is to drive a Fox Mustang
with hard tires and dead-stock suspension again, and all was well.
When we got home, I pulled the hood latch apart and found the problem.
The witness marks left on the metal by all those street miles indicate
that the latch striker blade had never had more than 3/16" of
engagement (overlap of the latch blade onto the hood reinforcement).
>From running the red car, we know that an unstiffened Mustang can see
3/8" or more of deflection due to twist in the front clip as you leap
off the apex of 8 and land on the left front corner at the turn-in for
8A in the Corkscrew. This deflection moves the radiator support to the
right with respect to the hood- exactly the right direction to release
the latch. As Cindy got going faster and loaded up the left front
progressively more, the resulting twist increased until finally the
deflection was sufficient to pull the latch blade off of the hood
reinforcement, and the die was cast.
Bang.
The hood latch should have at least 1/2" of engagement to really work
well on these cars. We didn't have anywhere close to that, but it had
surely never occurred to me to check it. After all, hood latches are
trivial parts that just always work, never require attention, and
never cause annoyance, right? Most people will never expose their
street cars to the kind of worst-case deflection that can be
experienced on a hot lap at Laguna. But we trackies do all the time,
and it'd be a shame to see this happen to a Shelby or a brandy-new
street car.
Wonder how many folks are going to go look at their hood latches after
<<<>>>
Meanwhile- I'll be installing a loop of aircraft cable and a pip pin
in double shear as a failsafe hood-retention mechanism for the blue
car, and I just doubled the number of hood pins I had in mind for the
red car. Who says that racing doesn't improve the breed? Most
amusingly of all, the pink slip for the blue car arrived from the DMV
in the Friday mail as we were loading it on the trailer. Just before
we left for the track, in fact. Foreshadowing? You make the call.
The downside is that the car is perhaps a little bit
appearance-challenged at the moment, even by my admittedly relaxed
standards. And, given that it *is* supposed to be Cindy's daily
driver, she has asked me to gather input on good body shops in the Bay
Area who are friends of the club and who understand that we're going
to do this repair out of pocket and charge us accordingly... Who's in
favor these days?
A call to Cervini's for a glass hood, a little hammer and dolly work,
a squirt of paint, and then back to the track wars! Hey, wait. Carbon
fiber hoods aren't _that_ much more expensive. Hmm...
13 Jun 1997
[email protected]
Ford
On Jun 12, Christopher Ferino wrote:
> My first major swap is going to be a Griffin radiator. It seems
> to be pretty much an in/out routine, but I'm concerned about the
> mounting of the radiator at the top, as the pictures I've seen of
> the Griffin radiators won't work well with the mounting brackets
> that are attached to the stock radiator.
You'll have to modify both the upper and the lower mounts slightly. The
uppers are quite easy. You simply have to trim the rubber a little bit
with an X-Acto knife, and spread the clamp fingers a bit. The tanks
are about 3/8" thicker for the Griffin, so you don't need to do much
stretching at all. You have to do the same stretching and trimming at
the bottom as well, but it is nothing that a person with two pairs of
pliers couldn't handle.
Just be sure that there are no areas where the steel bracketry
contacts the aluminum tanks without at least 1/16" of rubber between
them. This is a high-vibration application, and if the bracketry comes
in contact with the tank, it'll chew it up muy pronto...
I personally scrapped the factory rubber inserts, and made my own with
some fabric-reinforced belting I had around, since my application
involves track use and the radiator can be expected to _really_ get
slammed around. I also made my own lower brackets to improve the
security of the mounting, for the same reason. But very minor mods to
the stock bracketry will work just fine for street applications.
13 Jun 1997
[email protected]
Ford
On Jun 11, Rob Brown wrote:
> There part numbers are:
> SET 5 (Timken A-5) Outer (smaller) bearing w/ metal cage
> SET 12 (Timken A-12)Inner (larger)
>
> Watch out - the counter guy and I had a small arguement about these part.
> numbers. Seems their computer (and some other places computers) has
> SET 17 (A-17) for the inner bearing.
> Be sure to get the proper grease seals for the rotors. Seems the Bendix
> Rotors and the factory rotors have different grease seal diameters. I
> think the Napa computer has some reference to SVO parts.
> It all worked out in the end for my car (89 LX 5.0). The thing that
> still bothers me is the A-17 inner bearing thing. Anyone know why
> this is?? The A-17 is noticable smaller. (I should have seen it.)
They _still_ haven't corrected this? What a crock. This error dates
back to 1987. When the '87 GTs came out with the 11" brakes, many (if
not most) of the parts catalog companies *never updated* the entries
for the bearings and grease seals. The '86 and earlier cars, and all
the 4-cylinder cars with 10" brakes, use the A-17 for their inner
bearing, and use a smaller grease seal to fit the smaller bearing
bore. The SVO Mustang, the Lincolns, and all the '87-93 Mustangs with
the 11" brakes use the A-12 parts, even though the catalog databeese
seemed to all get this wrong way back.
So remember this: The aftermarket parts database is probably wrong. If
you have the 11" brakes, whether 4-lug or 5-lug, when you go to buy
bearings, tell them that you want the bearings and seals for the 1986
SVO Mustang. You will get the right parts. If you just tell them that
you want the parts for an '87-93 GT, you'll almost certainly get the
wrong ones.
I quit going to automotive parts outlets for these a long time ago, once I
discovered that the prices were 50% lower to buy the exact same pieces through
the industrial supplier channel (King Bearing, here in the SF Bay Area). But I
would have figured that they would have corrected that long-standing annoyance
by now- it's only been 10 years, after all...
08 Jul 1997
The Ernests
Ford
Greetings, everyone!
I picked up a new FMS clutch cable (actually, the kit that contains both
the teflon-lined cable and the heavy-duty fork) today. I went to the local
SVT dealer and asked for the stock, replacement cable; they quoted me $100!
I picked up my teeth, and asked how much the FMS kit was; the answer was
$36 (list is $45)! Not too shabby, and now I have a good fork, just in
case I feel the urge for a little forking... nyuk nyuk nyuk =8-D
10 Jul 1997
[email protected]
Ford
Regarding replacement fuel tanks for the fox body Mustang, the tanks
that are out of production are nearly twice the price of current
tanks ('94-'97) and are somewhat interchangeable. The differences
between the '86-'93 and the '94-'97 are that the newer tanks have
much stronger baffles around the pump (these commonly break loose
on pre-'94 tanks) and also the newer tanks use a four tang retaining
ring to clamp the fuel level sender and the fuel pump versus the three
tang retaining ring used for many years (back to the fifties, I think).
For a carbureted car you could use another fuel level sender in the
fuel pump hole (to block it off) and plug the vapor recovery hole.
10 Jul 1997
[email protected]
Ford
> I've read in both Don Alexander's "Performance Handling" and
> Herb Adams' "Chassis Engineering" that a larger or more effective
> rear swaybar can be used to tune out understeer.
>
> However, I've also heard that many Mustang autocrossers remove
> the rear swaybar. I've also never heard anyone have anything really
> positive to say about parts like Saleen's adjustable rear swaybar.
}[email protected] (Andre Molyneux)
}In a Fox Mustang with a mostly stock suspension, you might be able
}to get the car more neutral with a bigger rear bar. Unfortunately,
}this will likely be because you've decreased rear grip, not enhanced
}grip at the front any. The four-link rear suspension likes to bind
}up as it is, and anything that stiffens up the rear (poly bushings
}in more than one location, bigger bar, etc.) only increases the amount
}of bind. The end result is less grip at the rear, although it may be
}more predictable.
Aha! Someone that knows the truth. :) You can trick the Mustang into
"feeling" better, but usually at the expense of grip and times. Good job,
Andre.
I've experimented with this theory many times, with a variety of front and
rear swaybars on Fox-chassis Mustangs. On my '87 LX ESP Solo2 car, I tried
four different rear sway bars and three different front ones. They were all
stock Fox chassis ones, in various smaller diameters. The reason I tried
smaller ones was to try to dial out the understeer with cheap stock bars
(usually $10 each from the boneyard) and use increased spring rates to keep
the lean down.
I tried many combinations, down to a .55" diameter rear bar (from a
Fairmont, of course). Even -no- rear bar, for a good length of time. All
alone increased push (of course). With some smaller front bars (I think
.88" was a small as I dared to go), a neutral attitude could be had, as well
as monsterous turn-in. But the lean??? Yikes! It would take bone crushing
spring rates to dial the lean out - not an option for a real street car,
which was one of my requirements in my only street car, then.
The other local Fox chassis Solo2 gurus tried much stiffer spring rates and
various stiffer sway bar sizes, all at more horrific costs to ride quality
and sanity. The 1-3/8" front bar makes the car push like a pig, and the
stiffer rear bars (or add-on "adjustable" bars) ALWAYS reduce rear grip.
They cause the car to pick up the inside tire under hard cornering on race
tires, which "feels" good, but is not faster. Watch some close-up, slo-mo
video of the inside rear tire of a Mustang turning hard on race tires, with
big rear bars, and watch it get airborne... Watch some similar video of the
inside front tire, and it'll make you laugh! We even tried some "on car"
video, with the camera pointed right at the tire on Solo2 runs. UGH! Not
pretty.
For comparrison, my neurtal-as-all-hell 1LE Camaro uses a 1.410" hollow
front bar (its light AND mighty big), with a 910." rear bar (just went and
mic'd them). For some reason these monster bars work very well, on that
chassis. But it doesn't have the bind-o-matic rear suspension, like the Fox
4 link. ;)
I tried various rear springs rates on the Mustang, at some expense, only to
end up liking the softer than stock (which are 200-300#/in, variable) Global
West straight rate 220 #/in rear springs the best (I don't think they sell
these anymore?). I ended up with 700#/in fronts and the 220#/in rears, with
stock sized Mustang 5.0 bars again. Hmph.
Gave a kind of soft rear end, OK turn in, with decent power application
ability. No rear bar helps put down power better, but with horrific
understeer. Try it, and time the difference on a Solo2 course. This set-up
needed more front spring rate, but I hated the ride already, with metal
spherical bearing camber plates and poly bushed front control arms. It rode
like a damn garbage truck!
This final set-up, which I used for the longest time, still had a push.
This push somewhat went away with crazy camber settings (I liked -4.5
degrees the best - great race tire wear for Solo2!) and better caster. For
ESP legality (no more slotted strut holes) I ended up with about -3.2
degrees of camber, and way more push than I liked, especially at lower Solo2
speeds. And the camber hurt braking! Flatspotted inside front tires were
getting too common.
After getting tired of a push happy pig that still didn't brake or put power
down worth a damn (it only ran 13.3's, so about 270 HP max), and after
driving several of the stock 3rd gen Camaros that were starting to punish me
badly, I gave-in and turned traitor. :-O I immediately got faster in a
stock/slow 3rd gen cheby, but that's another story that no Mustang lover
likes to hear. :(
Andre summed up the stock Fox chassis problems and solutions better than
I've seen in a while. He was realistic and honest, which is good to see.
:) Fixing the Fox-chassis is not easy. There is no magic set-up that
removes all the Mustang suspension woes. No expensive super duper magic
kits to make the Fox chassis on par with the "other guys" stock suspensions.
Its weird, but not even the mega buck Grigg's buggies I've driven handle as
well "those other cars", especially when you consider the often times less
than ideal street manners of these fully custom suspension Mustangs.
Before you start to see red, I'm sorry if these anti-Mustang suspension
statements anger the died-in-the-wool Mustang fanatics, but it is a reality.
I've driven too many of both Ford and Chevy's pony cars, back-to-back, on
road race tracks and timed Solo2 courses, to think otherwise. It actually
angers me that I have to drive a damn GM hoopty to go faster than a Mustang
in Solo2, even with extensive suspension work on the Ford. :\
Anyway, that's my story and I'm sticking to it. ;)
30 Jul 1997
[email protected]
Ford
Regarding SVO fenders; There are exactly the same as regular mustang fenders
except for 3 holes that you need to drill for the side of the bumper cover to
attach to. Huge difference in price, too. Been there, done that.
23 Aug 1997
[email protected] (Dave Williams)
Ford
-> dunno about griggs, but someone in my latest mm&ff sells a double a
-> arm for 1995, and get this no welding or driling. I wonder how they
-> manage to pull that one off.
It could be done with a *really* short upper A-arm. I've diddled
around with some drawings, but while getting negative camber in roll is
no big deal, you also get horrendous amounts of camber in bump. With
the amount of camber steer you get in a modern performance radial, like
the 275/40-17 R1, you'd need a couple of Rancho steering stabilizers
just to keep the thing on the road unless your highway department is a
lot more on the ball than ours. Camber change on Jay's Corvette is
negligible, but it tugs and weaves like a drunk boxer on wavy roads.
With lots of camber it'd suck big time.
Assuming you manage to come up with an adequate geometry, there's
nothing to anchor the stuff to. I dropped by Bob Wise' place when I was
in Colorado a couple of years ago. He had his bare Asedan tub up on a
rotisserie. You could watch the front "frame" flex *several inches*
from nothing more than the weight of the bare tub as he spun it around.
For a serious trackie this won't do. You're looking at a cage, and
pulling the front bars through the firewall to the front suspension
mounting area, and lots of triangulation. And by the time you look at
this, it's about as simple and probably cheaper to just whack off the
whole front of the car and "front half" it, then build some bracketry to
hold the fenders and fascia in place.
MacPherson struts bite the big wazoo, but there ain't no *car* there to
attach A-arms to. I'm amazed the front end doesn't fall off already.
Alan James 105236,543
S9/Performance/Muscle 20-Mar-97
>>I hear that the Fox-3 hatchbacks are also pretty bad in torsional stiffness,
but that the coupes and the SN95's are much better.<<
My '85 with its T-tops was the absolute worst. Even my '92 felt like it was
built from Legos compared to my '95, but it could still use some help. For
highly-scientific testing purposes, I can wedge my fingers in between the door
jamb and the dashboard during tight cornering at speed. You can feel the space
widening and tightening slightly as the car hits bumps or drifts over rises in
the road. I have yet to hear a single rattle, though.
Charles Rozier 73261,2114
S9/Performance/Muscle 20-Mar-97
<>
I heard that Ford said the reason the SN95's have no hatchback is that they
felt that the hatchback would have had unacceptable torsional flex.
I have owned cars that were very torsionally rigid and cars that weren't....I
concluded after a string of British roadsters that you could have lots of fun,
and neutral, tossable handling, even without a good stiff chassis. I like my
Mustang because it's entertaining...not because it's particularly competent.
I think real competence is more important on the track than on the street.
02 Sep 1997
[email protected] (Brian Kelley)
Ford
Dennis Robinson writes:
> dunno about griggs, but someone in my latest mm&ff sells a double a arm
> for 1995, and get this no welding or driling. I wonder how they manage to
> pull that one off.
That's easy.. You can anchor it using the forward K-member attaching bolt
holes and the strut top mounting holes.
Of course if the arm is really that short you'll have too much
camber change and likely other geometry problems.
Lengthening the spindle (measured by the distance between the
upper and lower balljoints) will help negate the camber curve problems.
It is extremely difficult to produce an acceptable geometry using
a very short upper arm.
I'd want to review a 3D analysis of the geometry before buying.
Not to mention strength issues (just because it is for sale
doesn't mean it won't fail on your car)..
I've also heard from reliable sources (Griggs) that they will be
releasing an SLA. Should be interesting..
A local Shelby club Mustang has one (not Griggs) and is apparently
going faster and incurring less tire wear. I haven't had a chance
to check it out yet.
03 Sep 1997
Teddy Chen
Ford
> I was conversing with another 5.0 owner and we were wondering
> how you'd know if the front hub (same one as an SN95?) that comes
> with the M2300K kit is bad? Would there be noise? Would you be
> able to tell if you performed the 12:00 and 6:00 "wiggle" test (like they
> do in tech)?
yes, they're SN95 hubs.
i take the wheel off, spin the hub by hand, and check for free play.
if there's play in the hub, check the tightness of the spindle nut (which
you should be doing as part of your pre-track prep anyway). if
you can't get rid of the play by tightening the nut, the hub is dead.
the races are machined into the hub, and the hub is not rebuildable
(nor is bearing preload adjustable). i also look for any roughness
in the spinning of the hub.
every once in a while, i clean the brake dust off the hub and check it
for cracks, particularly where the flange meets the shell. the machining
of the races on the inside leaves a groove in this area, creating
a nice stress riser. SN95 hubs have been known to crack (or break
completely) in this area, and i believe Bondurant routinely replaces
the hubs for this reason.
don't skimp on this inspection. the hub needs to be clean so you can
see the surface clearly, and you'll probably do a better job of
inspecting it if you take it off the spindle.
BTW, pay some attention to the condition of that composite nut.
it's supposed to be self-locking, but i still get slightly nervous
at the thought of not having some kind of positive retention, like
a cotter pin. my driver's side composite nut was loose a couple of
times (as in less than 50 lb-ft of torque on it) despite being torqued
down to 250 lb-ft at installation, so i replaced it. the next time
those spindles come off, i'm going to drill them for cotter pins.
21 Sep 1997
[email protected] (Jim Dingell at Performance Parts, Inc.)
Ford
Ford did install a single-key lock system on Special Service Mustangs.
Unfortunatly, they did not consider it a "necessary" part after production
ceased and promptly discontinued it in the fall of 1993.
I recently provided a set of 1987-1993 Special Service Mustang locks to TLK
to "disect" and reproduce and make available thru better restoration shops
very soon.
13 Oct 1997
[email protected] (Walt Boeninger)
Ford
This may be a tough question, but you guys deal with those all the time....
Our '67 TA coupe uses what I believe are T-BIRD/Lincoln calipers. These are
bolted to a stock Mustang (previously '67 disk, now '70 drum) spindle via a
caliper bracket that looks like a production piece. The question is what car
did it come off of? The puzzling thing is this: The T-bird calipers have
threaded mounting holes. (The spare calipers I have are still threaded) The
ones on the car are not threaded, becuz the caliper brackets are threaded,
like the stock Mustang brackets. But bigger bolts and all.
So can someone confirm that '66 Tbird calipers look just like oversize
Mustang 4 pot KH calipers, with threaded mounting holes?
And what caliper bracket are these that are threaded and require the
caliper to be drilled so the bolt goes through to attach?
What is confusing is the fact that these caliper brackets are threaded,
and have the correct spacing for the TBird calipers, which are *also*
threaded....so these could not be off a Tbird...they don't mate...
Don't have time to peruse the boneyards, besides somebody out there
probably has the answers.
14 Oct 1997
[email protected] (John Edward Miller)
Ford
> Our '67 TA coupe uses what I believe are T-BIRD/Lincoln calipers. These
> are bolted to a stock Mustang (previously '67 disk, now '70 drum) spindle
> via a caliper bracket that looks like a production piece. The question
> is what car did it come off of?
Yes, they are Lincoln calipers. As for the bracket, I know it was included
in a kit Ford sold specifically for TA-prepping Boss 302s under part numbers
D0ZX-2B134/5-B but that's all I know.
03 Nov 1997
Teddy Chen
Ford
> >I just got some used aluminum CSA type 35 wheels. The ones mentioned
> >on the lists that might be one of the few 16" wheels that will hold a 13"
> >Baer/PBR caliper.
> They should clear a Baer setup and PBR calipers. However, Teddy found
> that the Cobra calipers have extra ribbing on them that will interfere
> with the rim.
actually, it's not just the fins on the cobra calipers. the calipers
themselves are thicker in several places, including the critical area
where caliper-rim interference occurs.
also, if you have an M-2300-K kit, just swapping out the Cobra calipers
for the plain PBR calipers won't solve the whole problem, either. the
SN95 hub places the rotor (and thus the caliper) further outboard
than the fox-based Baer racing setup. this increase the interference
between the caliper and the rim.
you can't solve this problem by running custom rotors on hats with more offset
inboard, either. the steering arm on the SN95 spindles was redesigned to
improve Ackerman steering, and the rotor had to move further outboard to avoid
interference with the steering arm. there's not much clearance as it is, and
i don't think i'd really want to tighten it up. the rotor gets pretty hot in
track use, and i'd want to minimize the heat transfer between the rotor and
the tie-rod end (heim joint in my case).
10 Dec 1997
[email protected] (Brian Kelley)
[email protected]
Bob Mahoney writes:
>Welcome to my world of Mustang rear end hell.
>
> I run a 1996 supercharged Mustang Cobra in club road racing events.
> Getting the power down out of corners is a major problem with the
> pro-squat and pro-dive geometry of the stock 4-link rear suspension on
> that platform.
You're not focusing on the real problem.
Bottom line: Fix your freakin' suspension and *THEN* worry about the diff.
*NO* clutch type diff is going to survive a suspension that regularly
completely unloads the inside wheel in corners and a driver who still
mashes the throttle (particularly with a blown V8).
Your best option to make that shit suspension work is a detroit locker
or one of the variants for the 8.8" - as you've already tried. You
can go really fast with that setup... BUT, you'll still be unloading
that inside wheel. Thanks to the full locking, you'll still have the
outside wheel driving the car forward (or probably more accurately,
sideways off the track!).
The locker with the 4 link produces an extremely tail happy car. It
should actually become fairly predictable, and the spectators will
love it. For Solo II, it can be a very fast setup and is not all that
unsafe. For road courses and high speeds, it isn't very driver
friendly (but again.. you can go fast with it).
Detroit lockers (and I assume the variants for the 8.8") are brutal on axles,
hubs, wheel studs and wheels. From what I've seen and experienced, each of
those components is a candidate for failure. Running a super charged V8 with a
locking diff, sticky tires and stock axles with C-clips is a disaster waiting
to happen. For 4 bolt wheels, 5/8" studs are mandatory. For 5 bolt wheels,
good ARP studs are mandatory. The 5/8" Morossos seem fine, but are prone to
break in the 1/2" size (I've seen those failures on the *front* of Mustangs
under braking!).
Fixing the rear suspension to remove the bind and allow the axle
to stay parallel to the track does wonders. Even a worn factory
traction-lok becomes tolerable. Higher horsepower cars with lots
of tire will still benefit from a tigher diff. And even with my
3 link, I still use the detroit locker.
> Next I tried a Pro-Auburn which contains a cone-disk clutch. The design
> of the clutches will handle only two conditions:
Been there done that, Auburns are junk, IMHO. A properly rebuilt
traction-lok seems like a much better solution.
But even in Auburn has a chance when used with a real suspension.
> Now I've installed the Pro-Trax unit. Excellent on the track if you can
> stand the occasional clunk-release and re-catch on one wheel or the other,
> giving the car a millisecond of torque induced yaw. It surprises you, but
> rarely upsets the car enough to matter.
That is a design flaw that they (or you) need to fix.
> The Pro-Trax has an independent ratchet for each axle. On the street it
> gives a feeling of torque steer very similar to a front drive car with a
> screwed up diff.
>
> Worst down side: Try making a tight turn in the paddock (or parking lot)
> at part throttle in first gear. You can create a bind/release cycle that
> threatens to tear the axles apart.
Again, a design/tuning issue. It is locking at too low of a torque
threshold.
> Current conclusions: I'm convinced there is no road racing application
> where clutch type diff's will work on a Mustang.
I generally disagree, but a lot depends on how much power you make and
how much tire you run. I don't care for clutch type diffs because I
don't have the time to adjust and rebuild them. There are also the heat
and friction issues. And for Solo II (where the suspension can still
gets unloaded significantly), they are not as consistent or predictable.
10 Dec 1997
Chris Herzog
[email protected]
> On Tue, 9 Dec 1997, Chuck Fry wrote:
>
> > Has anyone with a torque arm actually encountered a need for more rear
> > roll stiffness while running reasonable spring rates, or a need for less
> > spring rate while running adequate rear roll stiffness?
>
> I think most people just slap in much stiffer specific rate springs and
> are done with it.
It's certainly more tunable from the spring perspective.
> I'm more of a fan of a bit less spring and a bit more
> roll bar. At least from my search, there are no plug-and-play stiffer
> rear bars.
Steeda used to make a "helper" bar which added to the stock bar and Herb Adams
used to make some honkin' big 1" thing - I think I might actually have one in
my garage that I got as part of a big parts swap; I'll see and let you know
what the scoop is.
> > Seems to me it should be pretty easy to get a rear bar fabricated if you
> > really need one. The $99.95 question is, does anybody with a torque arm
> > really need one?
Spring or bar, you need more of at least one or the other IMO...
> I'll probably end up getting one fabricated next year. Griggs provides
> some really rude spring perches that look like huge washers to adapt the
> pigtail (bottom) mount area to a fat, straight spring perch. They grind
> and chirp nicely on the street.
They slide around a good 1-4-1/2" - I just ran a couple of small welds to nail
those things down once and for all.
10 Dec 1997
Robert Whitley
[email protected]
At 10:44 PM 12/9/97 -0600, Bot Mahoney wrote:
>Griggs provides
>some really rude spring perches that look like huge washers to adapt the
>pigtail (bottom) mount area to a fat, straight spring perch. They grind
>and chirp nicely on the street.
Those pig tail springs are rude indeed in this application. They are
intended to be used in the front of a GM product, I believe. Note that you
have to make sure that the open part of the pigtail is facing rearward or
they make even more noise. But, things aren't so bad because Griggs now
sells 450 (and maybe 500) springs with the beveled ends. In any case you
can get them cheaper from Suspension Spring Specialties which is where
Griggs buys them. You'll notice that your rear perches are now bent from
the 450 pigtails. SSS also sells the perches (normally used on the top of
the spring). I just run the bent perches with beveled end springs and it
doesn't seem to make any difference.
I can't find the SSS phone number here at work, but if you are interested
e-mail me and I'll bring it in tomorrow and also information about which SSS
springs are the ones that you'll need.
I've got a set of pigtail 450s for the Griggs rear setup which I will sell
for $10 plus shipping though I can't imagine why anybody would want them.
The beveled end springs are only available up to 500 lbs (last time I asked)
but SSS will do a custom set of higher rate at not too outrageous a price.
I keep thinking about a set of 550s.
10 Dec 1997
Robert Whitley
[email protected]
At 06:04 PM 12/9/97 -0800, Chuck Fry wrote:
>Has anyone with a torque arm actually encountered a need for more rear
>roll stiffness while running reasonable spring rates, or a need for less
>spring rate while running adequate rear roll stiffness?
On my 89 mustang semi-tack car, I've got Griggs coil overs at the front and
their torque arm and adjustable panhard rod at the rear. I've got my own
interpretation of reasonable spring rates, and I've run 350, 450, and 500 lb
springs (same front and rear with this Griggs setup). With the 500 lb
springs at the track, I needed more rear roll stiffness to get the car
neutral in high speed sweepers with stock bars front and rear, the panhard
rod set one hole below the top, about 26 lb cold pressure in R1 245/45-17s,
and 3 deg neg camber.
My solution was to raise the rear roll center (raise the panhard rod). With
the stock front and rear bars the car was a bit loose. Removing the rear
bar entirely got me to neutral. I suppose I could have tried 550 lb rear
springs without moving the panhard rod and I'm guessing that I'd have ended
up in about the same place. A stiffer rear bar could also have accomplished
the same thing. I don't have adjustable bars so my approach is to use
springs which are pretty easy to change. The car has gotten progressively
better as I've gone up in spring rate.
I've been told, however, that the A-sedan guys don't typically go over about
550 lb, and I may be close to the limit. Doesn't seem very stiff to me,
however. I'd have expected spring rates like 700 lb but maybe that's for
folks who run wide slicks. As I said, I run 245/45-17 R1s and they are
pretty insensitive to roll so maybe I don't need a stiffly sprung car.
>Seems to me it should be pretty easy to get a rear bar fabricated if you
>really need one. The $99.95 question is, does anybody with a torque arm
>really need one?
Adjustable bars front and rear would be nice. I haven't found the need so
far. One nice advantage of adjustable bars is that they can be set for zero
roll bias whereas the stock bars can have a twist which can't be removed.
As I understand it, that sort of thing becomes more important as the spring
rates get higher and everything (including the chassis) gets stiffer. I
imagine that the spring rate of my chassis is probably about like the spring
rate at the wheel of an Indycar. ;-)
Rob, another road racrer wannabe in training.
10 Dec 1997
Bob Mahoney
[email protected]
On Wed, 10 Dec 1997, Chris Herzog wrote:
> Bob Mahoney wrote:
> >
> > I think most people just slap in much stiffer specific rate springs and
> > are done with it.
>
> It's certainly more tunable from the spring perspective.
It is that. Personally, I can tolerate higher roll stiffness better than
extra-stiff springs. So I usually choose medium-stiff springs and a
little extra bar. This is the best compromise for track and street. And
I'm talking about some serious track abilities here. The '96 Cobra turns
times below 1'40" at Road America, up in serious Porsche territory. So
the car is a bit rough for the street, but it is still ok for commuting to
work in the summer.
> Steeda used to make a "helper" bar which added to the stock bar and Herb Adams
> used to make some honkin' big 1" thing - I think I might actually have one in my
> garage that I got as part of a big parts swap; I'll see and let you know what
> the scoop is.
I've tried the steeda helper bar. It works, but it is extremely progressive!
Imagine that, take a suspension that binds and becomes asymptotic with
infinite roll stiffness as you corner, most people use progressive rate
springs, so the Steeda helper bar is also extra progressive with compressible
springs on the end links. When I used the bar it did work, but only on
maximum cornering.
19 Dec 1997
Eugene Y C Chu
Ford
Teddy Chen wrote:
>yeah, i have the GW tubular lowers with heim joints up front.
>as you say, they should reduce some of the bind - however, my car
>also seems to have more lateral movement in the rear end than
>most other mustangs (judging by the rubbing on the quad shocks
>that i saw on the track with 225/50/16 street tires). that
>was with poly bushings at both ends of the upper control arms.
>yes, the car oversteered, but not too badly, until last year
>at sears point when everything i did made the car want to
>get sideways. tiptoeing through the esses sucks. even removing the
>rear antiroll bar didn't help much. so i replaced the upper
>control arms with SVO HD uppers (easier than changing the bushings
>in the differential). the rear sticks better now.
The lower control arms are only supposed to maintain fore/aft location
of the rear axle, not side to side. Side to side location on the
Mustang is supposed to be maintained by the upper control arms, which do
a pretty lousy job due to the mushy rubber bushings. The two are also
supposed to work together to prevent axle rotation during acceleration
and braking, which they also don't do very well due to the bushings and
the geometry of the arms. This is why you need something to either
assist or replace them. A panhard rod used with a torque arm is a good
replacement for the upper control arms.
>i already expressed my views in another message about GW's claim that
>you don't need a panhard if you have the GW lowers (i.e. they're full
>of it). in fact, i think the GW lowers are why my car has more
>rear axle deflection than most mustangs.
While I'm impressed by those huge heim joints in the GW lower control
arms, I've always wondered if they shouldn't be on both ends. Most of
the time when the car is cornering, the roll of the body will displace
the suspension on the two sides differently, so the control arms need to
twist relative to both the axle and the body. Of course, if you
replaced the lowers without doing anything else, the greater compliance
of the heim joint on the front of the arms will allow them to flop
around more. But they will solidly locate the axle in fore/aft, which
is what they are supposed to do.
20 Dec 1997
"K.M. Sen-Roy"
Ford
Recently, [email protected] wrote:
> Does anyone have the stock weight for a 87-93 Kmember? I was at a speed
> shop the other day asking about where the maximum loss of weight points
> were on my car. They said the K-member would be a good start. The
> tubular one they had was very light, but I don't know what the stock one
> weighs. It looks heavy anyway.
51 lb for an '88 convertible Mustang (with the x tubing) on a postal scale.
29 Dec 1997
Teddy Chen
Ford
> Realistically, the car will see
> some track usage - autocrossing, etc. It will also see highway usage
> carrying me back and forth to work about 25 miles one way. However, I
> do want to upgrade the suspension to be as tight as possible with ride
> quality not being an important issue. In other words, it just has to be
> liveable. :) I've read Mathis's book Mustang Performance II, but I
> tend not to believe most of what I read in publications. He does
> mention some fabrication techniques to increase the performance of the
> rear suspension, and I would certainly entertain something of that
> nature, but I wanted to ask you first, before I cut, welded, drilled, or
> purchased anything. Perhaps there are some "stages" that I might
> consider? For instance, bone stock control arms, rubber bushings, stock
> shocks and springs, etc., would be "Stage 0" and all-out, panhard,
> torque arm, custom built control arms, etc. would be "Stage 10".
>
> If you have any info for me, or can point me in the right direction, I'd
> sure appreciate it. If you come up with something cool, you might want
> to post it to Fordnatics as well as replying to me.
i'd say that there are a lot fewer stages than you think, because
there's not a lot you can do with the stock 4-link to
improve its control of the rear axle without increasing bind.
stage 1: most important part of this stage is getting rid of the soft
oval rubber bushings at the chassis ends of the lower control arms.
the cheapest way to do this is with polyurethane bushings, so i would
buy a set of poly bushings for the rear suspension and install all of
them except for the ones that go in the ears of the differential.
leave the bushings in the differential alone, or replace them with
SVO HD rubber bushings. i'd replace them while you have the rear end
lying on the floor. you can also use police/taxi control arms or
other after market control arms. avoid any box section, tubular,
or boxed stock control arms that have poly bushings in them (rubber
is acceptable). the steeda control arms have composite rubber bushings
in them, and they look interesting. they certainly seem to have
done well with them in IMSA. you can get rid of the quad shocks,
as they are deadweight now.
possibly stage 1.5: antisquat brackets. the benefits of these are open to
debate. i haven't got them, and theoretically, they should increase brake
hop. but a couple of AS racers use them, and they like them.
stage 2: adjustable shocks. i'd go with konis or tokicos. if you
get konis, buy the SN95 model so you can adjust them without having to
remove them. you should probably buy a set and do the front and rear
at the same time. maybe this stage should come before the bushings.
_don't_ waste your money buying quad shocks.
stage 3: springs. buy as a set. for bang for the buck, you can't beat
the SVO springs (i forget the #, but the spring rate is about 700 lb/in
for the front) at $125 for the set. if you want stiffer, go with
Eibach Competition springs (700-850 lb/in up front). mustangs unlimited
has these at a good price.
stage 4: IMHO, you've now come as far as you can get with the stock
4-link rear suspension. it's time to lose the upper control arms.
get a torque arm/panhard rod. right now, Griggs seems to be the only
viable player in this market. Roush Racing has a torque arm, but they're
not selling it. there are a few other torque arms and panhard rods, but
they're either not for sale, no longer on sale, or intended to work with
the upper control arms in place. you can retain the stock lower control
arms with poly bushings in them for now. you might also consider other
kinds of rear suspensions, such as a 3-link, a real 4-link, a satchell
link, a watts link instead of a panhard, independent rear suspension, etc.
but there aren't really any good off-the-shelf solutions, and they
will require considerably more work and possibly development time
than the Griggs torque arm/panhard.
stage 4.5: trick Griggs rear lower control arms with adjustable ride
heights. you might also go with coilover shocks in the back.
stage 5: build your own rear suspension. how about a 3-link with
the third link running through a hole in the floorpan all the way
to the dash crossbrace on your rollcage? a decoupled torque arm
with the brakes mounted and controlled independently of the rear end?
or stick a Jaguar IRS under your car?
BTW, you may have noticed that i didn't mention adjustable rear antiroll bars.
that's because the ones on the market are all at least as stiff as stock, and
i don't think you need that. i'd rather be able to go softer on the rear
antiroll bar. the only time i'd want a stiffer rear bar would be if i'm
having a problem with lifting the inside front tire in corners (indicating not
enough rear roll stiffness), and even then, i'd prefer to look for more rear
spring.
i have a theory about why people are so big on rear suspension add-ons
that compromise rear traction, such as bigger rear antiroll bars,
bolt-on panhards, and axle-locating devices that are supposed to work
with the stock 4-link (and create more bind). it's because they
compromise rear traction to the extent that the rear comes loose
before it has the chance to go schizophrenic. the rear becomes more
controlled and predictable (predictably worse?), and that's what they
notice. so in their book, it "handles better". they are happy as
clams, and that's great for them. but in my book, some of that slop
that they just got rid of was compliance that helped keep the rear
tires on the ground. as dave williams pointed out, some of the fastest
cars are absolute pigs to drive.
29 Dec 1997
nick hagen
Ford
I have an '85 Gt and looking into installing a manual rack. Hopefully
you'll be successful so I can follow your lead. I haven't seen a lot of
info on this either cuz not many people do it or because it's usually a
trivial deal. The only sketchy info I've run across are:
Flaming River makes an all-new manual rack for around $250. Don't know
anything about it's dimensions.
In the January 1996 Car Craft mag "460 into Fox chassis" article, a
manual rack No. E1DZ-3504-AX is recommended along with coupler
D9BZ-3A525-A (if needed).
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