Mustang Cobra rear suspension

[DanDarcy]

Hi Fellows thanks for the comments
To Scott (and Will since Scott made you say it) I have decided to stop driving. I have turned in my license since not only can I not get traction on turn 4 but I have even lost traction coming on to the main straight , also turn 10 the right rear goes up in smoke. I even spin the inside tire on the downhill to the main straight at LRP. The car only has 305 h.p. but is very nose heavy. It makes for a thrilling ride :help: , I will check the posi unit.

to Timmy with the Audi-- I ran WGI in Aug. with the Audi club--- They are SLOW !!! Plus I have 4 Audis right now--don't need a race one too.

To Greg and Scott --thanks for the suggestion on line -- but I have tried all kinds of lines going up turn 4-- same results any line-- with my Z06 (only used it for two school days) traction was better if I went in deep and got going straight sooner, I have a BMW M Roadster 315 h.p. which I would like to try but I don't want to put a rollbar in it , only 6000 miles on it. and has good weight distribution.

I need tires so I will try some compition type DOT tires as Joel and serval of you suggest. I have 18x9.5 rims I'm not sure if 315s will fit , but maybe 285/35

To troyv -- The yellow Cobra 03 was running in the STGT class, I don't think he ran the time trials but had much better traction up the hill than I did.

To Raj--- I don't have a Subie---- But I have a Miata , and the Miata guys told me not to get a Subie, and the Mustang guys told me not to stop using the Mustang-- so since I don't use the Miata, why would I want a STI not to use it also. Plus neither the Miata or a STI is anywhere as exciting to drive as the Mustang.
Thank again for all your suggestions,

Dan D'Arcy
Mustang #310 ST1
Miata #210 SSB

[timmmy]

to Timmy with the Audi-- I ran WGI in Aug. with the Audi club--- They are SLOW !!! Plus I have 4 Audis right now--don't need a race one too.

Hey Dan, man it sounds like you have a lot of nice toys cant wait to see some of them next season.

to your comment on Audi's.....



500WHP (at all 4 wheels not just 2) cant really be SLOW! Although some of the guys at the quattro club do drive like my grandma

Cheers and ill enjoy passing you after turn 4 next season in my slow Audi


timmmy

[enjoythemusic]

Some very good advice, and humor, on this thread. You guys are brutal... and funny! Thx, been a bad week and i NEED the laughs.

Have been advised that in my car it is better to take the closer line versus going wide to avoid the bump, but will try both this year and see the results. Of course stickier tires can help cure some wheel spin as others have mentioned.

"would having traction up the hill be worth having to sit at the Subaru table at the dinners"

ROFL... but then again a tweaked WRX can kick my decades old car's arse so what do i know?

[rajito]

To Raj--- I don't have a Subie---- But I have a Miata , and the Miata guys told me not to get a Subie, and the Mustang guys told me not to stop using the Mustang-- so since I don't use the Miata, why would I want a STI not to use it also.

Why? To pass Miatas and Mustangs at NHIS, of course!

Raj --> :violent1: <-- Scott
Raj --> :violent5: <-- Lee

Hehehe
Raj

[offcamber09]

To Raj--- I don't have a Subie---- But I have a Miata , and the Miata guys told me not to get a Subie, and the Mustang guys told me not to stop using the Mustang-- so since I don't use the Miata, why would I want a STI not to use it also.

Why? To pass Miatas and Mustangs at NHIS, of course!

Raj --> :violent1: <-- Scott
Raj --> :violent5: <-- Lee

Hehehe
Raj

Raj, of course you meant "Mustangs an Miatas" in that order- or someone might think I was the Miata driver [-X

[timmmy]

stop it ...it hurts...

[dinoracer]

but then again a tweaked WRX can kick my decades old car's arse so what do i know?

Yeah, I know what ya mean there!

[Don P]

Dan -

I was wanting to send a pm but you're not listed on the member directory so here goes my couple of thoughts (as an X Cobra driver having had the same problem initially).

If Nhis #3-4 is the only place (of the tracks we run) your spining the wheels then manage the throttle and try adjusting the line as others have suggested.

Two other thoughts though are to go to 17X9 wheels with 275 rubber and lower the rear end gear ratio. With your motor's reving capabilities probably a 3.70:1 rear gear will allow a moe gradual traction rate increase during acceleration on the rear tires than the gear you have now, which once breaks loose is diificult to gather in and get going again. Some before you like Brad Pellitier ran 4:11s with good success.

Good luck,

Don

N.B. with my 1.6 configured Miata it was also easy to break the rear loose without the proper line and throttle control through 3 and 4.........dp

[DanDarcy]

Hi Don ;

Thanks for your advice , I have a 4.11 rear end right now but I have the tall 18" wheels with 265/40-18 tires. I can spin the rear tires loose on just about any corner , my rear wheels have just over 1400# on them according to the NHIS scales, my front tires have 2260# on them, I am very nose heavy besides being personaly heavy . I did notice on your old Mustang, that Craig has has two rear sway bars., does that help ? I' ve tried all different lines through 3-4 and have trouble no matter what. I think my posi unit is real weak, I might try redoing it.

NEWS FLASH --- I've cured my problem-- I'm going drifting !!!!! :salute:

P.S. Raj I think your smileys are hitting the wrong way you should be hitting Scott over the head--not him hitting you over the head

Dan D'Arcy
Mustang #310 ST1

[Don P]

OK -

Some more questions/comments. We can carry this on on pm if you wish.

Eibach springs -what rate front & rear?

Eibach shocks - adjustable?

40% on rear isn't right - unless you've got a dead body in front of the radiator that hasn't been discovered yet. It's more like 46-48f & 54-52f.

Ditch the 18" wheels go with 17x9 or 9.5" with 275 DOT RACE rubber (Toyo/Kuhmo) on all four corners.

Change the rear gear clutchpack combo (keep your 4.11) to be more like the F150 - which your local Ford dealer should be able to help you with..

I think poly bushings are legal in your class - do them

Change to larger diameter sway bars front and rear (with more attention to the rear).

If you do not have caster camber plates get them. Max caster and camber will help that rig down the straight and through the turns.

Tire pressures have a big handling influence on the Stangs - something else to talk about.

Best,

Don

[rajito]

P.S. Raj I think your smileys are hitting the wrong way you should be hitting Scott over the head--not him hitting you over the head

I think I'll need a fire truck ladder or something to be able to reach that high up

Raj

[brucesallen]

(hinted by some above)
The standard technique for cars with high power to stick ratios is "point and shoot". Any time you find your car getting wheel spin exiting a corner the driving style should be changed to brake to very slow before and in the first half of the corner, drive deeply into the corner turn the car sharply, aim for a very late apex and then put the hammer down and accelerate straight out of the corner. That means that your high powered, or undertired and poorly suspended car will be have maximum acceleration early in the last half of the corner for maximum exit speed.

With any car that has wheel spin in turn 3 and 4, slow the entrance speed, turn more sharply and increase the radius of the turn at exit until you just eliminate wheel spin. And don't forget to use all the track on the left side of the track at turn 4 to increase that redius.

I think it was Dan Gurney in his 427 Cobra in the sixties that said "I'll know when I have enough horsepower when I cam spin the wheels all the way to the next corner".

[DanB]

You need a SMALLER rear anti-roll bar, hell you might even ditch it altogether. With your power and, er, UNFORTUNATE F/R weight distribution, the only way you're going to get drive up the hill is to make the front take the lion's share of roll reaction. Bigger front bar/smaller or no rear bar. What's your front camber situation? You'll probably need more...

Bruce,
I thought it was Mark Donohue who responded to the question "how much power is too much (or enough)" by saying he didn't have enough until he could spin the tires at the end of the straight. 1000+hp 917-30 didn't have enough, I guess!

[brucesallen]

Ohyeah, Mark Donahue

[DanDarcy]

I'm no Mark Donahue or Dan Gurney but I can almost burn rubber at will. On the street if I shift into 2nd gear at 2500 rpm , let the clutch slowly than floor it after the clutch is all the way out, I can leave over 200' of rubber . Usually you have to let off before traction returns because the rear end realy steps sideways.
My Mustang actually has 43.7% rear , 56.3 % front distribution, which I realize will be tough to over come no matter what I do.

I have not heard of removing the rear sway bar. Does your Z have a rear sway bar Dan ? I have heard of going to softer springs with a stiffer rear bar.
I'm not sure what I'll do but that April NHIS will come up faster than we all think. I may need snow tires for that

Dan D'Arcy
Mustang #310 ST1