Anybody trying to go autocross this weekend?

[dewittpayne]

JY,

You have 335 Hoosiers on your car. I have 275 Bridgestones and way less torque. You can afford to transfer weight to the front so you can put power down at the rear. I can't.

Full soft on the front bar and the Watts Link one hole below the middle transformed the car. No wonder it felt like it had no grip on my first run on Saturday.

[dewittpayne]

Jed,

Did you run both days? I see your times for Saturday. You were twelfth in Pro, but no times for Sunday.

[jcox07]

DeWitt the regular esp mustangs are 5.0 just like your and watts bar all the way up and front bar on full stiff and rear bar on full soft unless they are at 650 front spring rate then they are at full soft on front and rear. The Hoosier don't make the car balanced.

[dewittpayne]

The Hoosier don't make the car balanced.

That's my point. The Hoosiers would make the car oversteer with normal suspension settings on a live rear axle car because they have so much front grip with all the negative camber you can use on the front suspension. You need to transfer as much weight to the front as possible to balance the car. Setting the Watts Link in the top hole, the front sway bar on full stiff, the rear bar on full soft and really stiff front springs compared to the rear accomplishes exactly that. I'm betting that the 2015 Mustang won't have that problem in ESP when the parts become available.

I don't have that kind of front grip. I know for a fact that on 275/35/18 Bridgestone RE-71R's with the front bar in the middle and the Watts Link two holes from the top, my car is a pig. You turn the wheel and it thinks about turning, but not very hard. It was very much like when I tried to run the Dunlop ZII's on the car with only 36 psi in the front tires. Everybody in FS that ran those tires had at least 42psi in the front tires.

And finally, Sam said I should start with the Watt's Link in the middle hole, not the top or bottom.

[jdpeterson21]

Ah. Thanks Dewitt. I stared at that for at least a minute and couldn't find my name.

[jcox07]

Dewitt, I have done everything there is to do to a mustang and I too have used Sam as a tool to get it to where it is, but I am just trying to help you and I have tried, I know exactly where Sam told you to start with everything but if you would listen to me you would get there quicker. It is your car and it is lighter than mine with not as much power, but if you think they are that much different than the 5.0 mustangs in esp then you will always be searching for the right setup. Power and weight in your car is the same as the other esp cars and they have the cars dialed in with 650-700 pound front springs and full soft on front bar and full soft on rear bar and under 500 pound front springs the front bar is on full stiff and rear bar full soft with the watts link all the way up on either of those to setups.

[integra55]

you finished 12 day one pro

12 m STR 10 Peterson, Jed 08 S2000 White 58.036 57.222 58.255+1 57.342+2 ….47.952 +0.016

[dewittpayne]

JY,

All I can say is put 275/35/18 Bridgestones on your car and see how it handles with your setup. You can even borrow mine at the test and tune at the Wilmington Tour. I'm betting it will have terminal understeer. When you have push in a front engine RWD car, you don't increase front roll stiffness. That makes it worse.

With the front sway bar set in the middle I drove into an Interstate cloverleaf at speed and nearly went straight off the road. It was much better at full soft.

[jcox07]

I started modding my car with hoosiers first with a stock set up and it didn't help, then went to sway bars and coilovers with only a little help, when I finally got the car right it is right on hoosiers or my federals, the car does the same thing with either of the tires. Now I'm not saying that I can't drive it in deeper and put power down faster cause I can, but if your car is doing something funky like what you said it did entering the highway, you may have a bracket broke on the front sway bar mount. I can bring wheel spacers and put my hoosiers on your car and it WILL NOT fix the problem you are having. It took me 2 years to finally hit the right setup and with help from some of the other esp drivers, Mark and I changed the position of the watts bar to all the way up and it made a huge difference and we didn't go to full soft on the front bar till I went up to 550 on front spring rate. It will be a learning curve but we can play around with it at wilmington. Most of what you are getting I think is in throttle response meaning too much gas and you miss your braking zone and you are carrying too much speed to get the car to do what you want it to do and late braking which puts you out of the line you need to be in to power off of the corners. Try adjusting those two and if it helps then you will be in the ballpark and you can adjust the car a little but making adjusts to the car won't make the driver faster until he/she learns those skills as it took me a couple years to understand to go faster sometimes you have to go slower in some areas of the course.

[thrdeye]

When you have push in a front engine RWD car, you don't increase front roll stiffness. That makes it worse.

I'm going to disagree with this because the statement is too general.

My understanding is you have a McPhereson in front of those Mustangs, which means your suspension pickup point at the top becomes more vertical as the car rolls, which should make your outside front tire lose negative camber. I have no experience with rear suspensions on cars like yours, but I'd be willing to stiffen the crap out of the front to try to prevent losing all of my static negative camber during roll and compensate for any understeer that is present in some other way. Stiffening the front of a car does not induce understeer in all situations....especially a nose-heavy mcphereson car on tires that are really too small for it.

Car balance is an iterative situation that is continually changing. Again....I have no experience with rear suspensions on cars like yours.

[jcoatney]

You all are making my brain hurt. I'm a driver, not a thinker.

[dewittpayne]

Chris,

I've installed the Maximum Motorsports K-member on my car which raises the chassis pickup points of the front control arm by 5/8". That's going to raise the front roll center compared to the stock mounting points and improve the camber curve. And I've installed a bumpsteer kit, neither of which are legal in ESP. If I were in the situation you describe, which is probably the case for McPherson strut suspensions that have been lowered too much with the stock bump toe in, softening the front sway bar should have increased the push. It didn't. It decreased it.

I'm pretty sure my car hasn't been lowered as much as JY's car either. I can get a jack under the pinch weld without having to drive the car onto a ramp. My ride height is pretty close to the ride height of a NASA American Iron car, which is what the MM K-member was optimized for.

[steverife]

That's a lot of stuff to get wrong.

[John Brown]

........................ Miata

that is all.

[dewittpayne]

That's a lot of stuff to get wrong.

Yup. The more adjustments you add, the easier it is to get lost. See, for example, four way adjustable shocks. Formula 1 doesn't use adjustable shocks. They can calculate what they will need for a given course, not to mention the 7 post rigs they have for testing suspension dynamics and the data they get from the onboard sensors.