Mustang Cobra rear suspension

DanDarcy · Post by **DanDarcy** » Tue Jan 17, 2006 8:48 pm

I have a 1997 Mustang Cobra ST1 car, stock engine and transmission but I can't get traction to the rear wheels especialy going up throught turn 4 @ NHIS :dontknow: . I have 265/40-18 P-Zero tires, Eibach springs and shocks, Ford Motor Sports lower control links , every thing else is stock. The car weights 3600# and have only 40% on the rear wheels ( I know , I know they don't handle but they are exciting to drive and hang on to) Does any body have any sugestions on how I can improve rear traction and grip ? and I don't mean getting a different driver (I think Scott might propose that)

I don't want to go to SP just stay in ST1. Thanks

Dan D'Arcy
Mustang #310 ST1

offcamber09 · Post by **offcamber09** » Tue Jan 17, 2006 9:26 pm

Man, I'm developing a bad rep on this forum...I LOVE IT !

In all seriousness, Dan, we need to find a different driver for your car....

Ok I'm done....

Inside wheel spin (rr) up the hill in 3/4 NHIS is unavoidable in a stock Mustang unless you are slow.

My car has a Torsen T2r diff. , custom rear lower control arm set-up, a panhard bar, torque arm and I still fight wheel spin- only it's both rears braking free.

The Torsen made the biggest difference- but I don't think that is ST legal (?)

I also use a tighter line through 3 into 4 than most with higher hp cars- by doing this I'm trying to get the car pointed in a straight line sooner for the launch up the hill. Also this avoids the bump on the left side of the track which rotates the car in the right direction, but in my opinion wastes rear traction that could be used in the launch ...then again I'm not very quick at NHIS so what the hell do I know.

Post by **dinoracer** » Tue Jan 17, 2006 9:59 pm

Hi Dan

I feel your pain; I'm fighting the same issues too.

I think a set of stickier track-only tires will help you, Kumhos or Hoosiers come to mind.

Other than that I'd call Max Motorsports, Steeda, Griggs etc, see what they offer. Also, there is a lot of tech on-line available, a lot of it even good. Corral.net is decent. Another is Corner-Carvers.com - there is a lot of Mustang content, and some pretty serious math and theory if you want it, but be sure to search extensively before just posting "how do I go faster??", they are pretty rough on newbies asking questions that have been beated to death already.

Of course you could just ditch the IRS, and come to SPA with Scott and me...> We'll play nice

Post by **TroyV** » Tue Jan 17, 2006 10:44 pm

Scott,

Wow. A T2R is an automatic bump from ST to SP? I need to read the classing rules again.....I can't do anything to my car

I was going to suggest to Dan that he might benefit from an 03 IRS swap if he didn't want to go the TA/PHB route. There are a lot of nearly new 03 IRS' complete on the web for relatively short cash. Lots of 03 guys swap to solid axles to drag race....sort of a waste in my opinion..

Then that got me thinking....would an IRS on a 97 Cobra be a bump?....or does that fall under the update/backdate thing?

offcamber09 · Post by **offcamber09** » Tue Jan 17, 2006 10:59 pm

With my last bone stock motored '89 Mustang I was bumped into SPA with springs and a panhard bar. I'm not sure but I don't think you can change diffs and certainly not go from solid axle to IRS without a bump.

I agree with Tom about corner carvers...lots of slide rule type info and you better bring your A game if you are going to post. I got the sh.t kicked out of me trying to debate the cons of ABS braking in a race car.

timmmy · Post by **timmmy** » Tue Jan 17, 2006 11:10 pm

You could sell the mustang and build a 'quattro' to SPA and come harrass Scott with me

later this year (or maybe next year)

hahah just kidding, but I cant ffer any advice apart form to let you know that my miata with almost no HP can slip there too, use the go pedal a bit later

Timmmy

jadams · Post by **jadams** » Wed Jan 18, 2006 12:53 am

I am certainly not an expert on Mustang suspension, but I assume that it behaves similarly to many other rear drive cars. Without changing diffs, the easiest thing that you can do is experiment with your line so see what gives you the best results. The key is to apply throttle as smoothly as possible to minimize the wheel spin. Once it gets out of check, you will need to back off to regain traction and thus you will lose time. The highest amount of traction occurs just as the wheels begin to slip, so if you can modulate the throttle to stay right on this fine line that would be the fastest way up the hill. As other have mentioned, race tires would also be a great help in this endevour. Not sure what tires you can run in ST, but I went to 315's from 265's and saw a huge difference in available traction.

Good luck!

rajito · Post by **rajito** » Wed Jan 18, 2006 1:47 am

Get an STi.

Raj

offcamber09 · Post by **offcamber09** » Wed Jan 18, 2006 10:46 am

When I got bumped to SPA for adding a panhard bar it made me think about how you need to go into a COM class with your eyes wide open. For instance, if I had a Camaro instead of a Mustang with exact same mods I would have been in st1- the Camaro came stock with a panhard bar. So what did I do- I built another Mustang ](*,) . I agree with Joel that altering your line and/or throttle application is the only "legal"

way to make a difference in a st car.
As far as getting a Subaru to make it all good you've got to ask yourself "would having traction up the hill be worth having to sit at the Subaru table at the dinners" ?

JackFFR1846 · Post by **JackFFR1846** » Wed Jan 18, 2006 12:32 pm

offcamber09 wrote: As far as getting a Subaru to make it all good you've got to ask yourself "would having traction up the hill be worth having to sit at the Subaru table at the dinners" ?

Hoosiers. The good: Stickier. The bad: You'll wear them out twice as fast as Kumho/Toyo etc.

You could offset that by getting a 1600 pound car......like mine.

The Subaru table is not that bad. Raj is less scary than you would think.....but Alex is far more scary than you would ever imagine!

I will refrain from posting "that" picture.

jack

kfoote · Post by **kfoote** » Wed Jan 18, 2006 12:44 pm

The Mustang IRS is not good over bumps. At all. That having been said, your best bet is to slow your entry a bit into 3, turn in a bit later, apex a bit later, and gat the car pointed straight before gettig to the transition bump going off the oval. You will not be able to go full throttle until after the suspension compresses after the transition bump, but once you do get the compression of hte hill, you should be able to modulate the throttle to minimize wheelspin going up the hill. For turn 4, the fastest way through is to let the car go where it wants to and not pinch the car to the inside. If you're not using all the track on the exit of 4, you have too much steering input.

gread · Post by **gread** » Wed Jan 18, 2006 4:04 pm

I have a BMW with an independent rear, an rear and a fair amount of hp. Traction up the hill on 3 always requires rolling gently on the throttle. I agree with Kevin the best way to get power down going up the hill is to change your line. I brake late, apex late and get the car pointed up the hill straight as soon as possible. I avoid the outside bump altogether because it upsets traction for me. Your car, like mine, is not a momentum car. Getting straight is usually the key to getting faster.
Sometimes, big powerslides up the hill do provide miles of smiles.

Post by **TroyV** » Wed Jan 18, 2006 5:12 pm

Not to hijack this thread, but, Is there anyone in STGT running an 03 Cobra? I'm familiar with Brian Stonkus' RS3 which is a GT with an Eaton slapped on top. It seems like my car is sitting on a line where modding almost anything means a bump to SPA. I saw one fellow with a Yellow 03 at one of the NHIS events (I was not running, but spectating) I neglected to ask what class he was running in. I guess I'm looking to see where the breathing room is. I have already planned to down pulley the car to the stock boost level....that is more to get me in less trouble as an intermediate level driver, and also to run the car in a slightly cooler range. Maybe someone can help me go though my car on the phone or by email and help me class it out. I spoke with Scott yesterday on this and I still think the car fits into STGT. As I said before, I'm less interested in time trialing and really in it for the practice days...but I plan to trial if I'm going to be there anyway....particularly where the away events are concerned.

Post by **Mick** » Wed Jan 18, 2006 5:33 pm

T,
I think you're takling about this guy
http://www.jeremykeith.com/index.cfm?p= ... g_0924.jpg
I just looked through the results page. #71 is listed as a Miata in ST3. It doesn't apprar that the Cobra ran the TT.

Post by **WillM** » Wed Jan 18, 2006 7:43 pm

I don't know much about Mustangs, but I am fairly familiar with the ST rules. Per page 20 of the 2005 COM rulebook:

X. Street Touring
7. F. Updating and backdating of differentials is allowed within the same manufacturer. Any aftermarket limited-slip differential may be used provided ratios are among those available on OEM differentials. Welding or locking differentials are prohibited.

As they say: When all else fails, read the instructions.

If the torsen drops in and retains an OEM ratio found in your Mustang, then it should be ST legal. The trick is that the diff has to drop right in. No custom fabrication, mounts, etc., are allowed. Keep in mind that any modifications not expressly mentioned in the SS or ST section of the COM rulebook are illegal in ST.

Worst case scenerio, you could find another driver. Sorry, Scott made me say it! O:)

- Will

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Mustang Cobra rear suspension

Mustang Cobra rear suspension

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