Anybody trying to go autocross this weekend?

[integra55]

David Black is co-driving with me … hope I can learn something

[dewittpayne]

I learned my tire pressure was too high. Jadrice sets his pressure at ~30psi cold front and rear with basically the same tires on his 2015 Mustang and never messes with it after that. Unfortunately, the other changes I made to the car induced near terminal understeer. I'm still waiting for the final results to be published, but the unofficial results had me nine seconds slower on a sixty second course than the class leader on Sunday, 57.xxx vs my 66.4xx. *sigh*

Edit:
I was wrong about the 9 seconds thing. I wasn't the class leader on Sunday, but I was enough faster on Saturday to keep the overall lead by 0.2 seconds.

Here's a video of my (not very) best run on Sunday: https://youtu.be/4Mutqxxai3U

Mostly, I'm just not going fast enough. The little ball on the acceleration display should be red more often, for one thing. As usual I suck in high speed slaloms. Maybe I can get David Black to codrive at the next zMax event.

[Gen52SS]

DeWitt can you post the link for the results. I can't find it.

[dewittpayne]

Paul,

It's in the CCR Forum: http://ccrscca.proboards.com/thread/658 ... lo-results

[Gen52SS]

N I C E....congrats on the win. Your the man to beat in CAM...OH wait J. Coatney... I didn't see Jadrice was he there. Rasmussen also did well in FS.

[dewittpayne]

Look in Pro. Jadrice was 8th with an FS PAX. He was about 4 seconds over two days faster than Dick Rassmussen on raw time.

[Gen52SS]

Okay...found it...4 seconds guess they both out PAXed you...both he and the car are fast.

[dewittpayne]

If I can get the balance right, I should be a bit faster. Maybe even as fast as a Street 2015 Mustang.

[jcox07]

Dewitt, which sway bars are you running and where are each at as far as full soft or what settings are they?

[integra55]

I learned my tire pressure was too high. Jadrice sets his pressure at ~30psi cold front and rear with basically the same tires on his 2015 Mustang and never messes with it after that. Unfortunately, the other changes I made to the car induced near terminal understeer. I'm still waiting for the final results to be published, but the unofficial results had me nine seconds slower on a sixty second course than the class leader on Sunday, 57.xxx vs my 66.4xx. *sigh*

Edit:
I was wrong about the 9 seconds thing. I wasn't the class leader on Sunday, but I was enough faster on Saturday to keep the overall lead by 0.2 seconds.

Here's a video of my (not very) best run on Sunday: https://youtu.be/4Mutqxxai3U

Mostly, I'm just not going fast enough. The little ball on the acceleration display should be red more often, for one thing. As usual I suck in high speed slaloms. Maybe I can get David Black to codrive at the next zMax event.

here is my fastest (clean) run on Sat … for some reason the Sat course didn't seem to "fit" me … I really couldn't get the hang of it … I was 5th at the end of the day

https://www.youtube.com/watch?v=uUAOJlMl-Bk

and here was Sun quickest run … no sure of the difference in the courses .. but I seemed to do much better on this one … finished 3rd and moved to 3rd for the weekend .. not the least helped by the first day leader not being there on Sun … but then the eventual winner did whup my but by 1.2 sec (a '88 CRX that weighs ~ 350# less than mine … yeah … that's my excuse … LOL

https://www.youtube.com/watch?v=zXs5HHLHIrQ

[dewittpayne]

I'm running the Strano adjustable bars front and rear and Maximum Motorsports 435H0 springs, which are a lot stiffer than the Steed Ultralites I had. Right now, the bars are in the middle on the front and full soft on the rear. I also moved the roll center up to near the top. I had the rear axle lower control arms set to the bottom hole of the bracket, but moved it to the hole that put the arm parallel to the ground at static ride height to eliminate the roll toe out. Moving the control arm took out more oversteer than I thought it would. All the other changes increased understeer.

Before I moved the control arm, I had the front full soft, the rear in the middle and the roll center about one hole down from the middle. I'm going to move the roll center down first and see how that feels. If it's still pushing, I'll soften the front bar, test and then stiffen the rear bar if it still needs it.

[jcox07]

When I had 400 pound springs up front with the strano bar I was on full stiff on the front and full soft on the rear with the watts link all the way up with 250 pound springs. The car is balanced and rotates very well, not sure what is up with yours.

[dewittpayne]

The MM rear springs are progressive. The rate at ride height is 320 front at ride height and 360 at 2" compression. The rears are 260 at ride height and 380 at 2" compression. So the rear roll stiffness on my car is a lot higher than yours with 250lb springs. Your weight distribution was probably more to the front than mine also. Then there's the difference between R-comps and street tires, even RE-71R Bridgestones.

Was that with the stock rear control arms? If so, a lowered car has massive roll toe in because the axle end of the control arm is higher than the chassis end. You would want to minimize initial rear roll on corner entry by using a rear roll center as high as possible. The transient behavior improves too because the weight on the rear axle transfers faster because there's less roll. But it also induces understeer. With the rear control arms parallel to the ground you get minimum roll toe in.

If the axle end of the control arm is lower than the chassis end, you get roll toe out, which might help with turn in if you can keep the car under you. I didn't like it. The car was too twitchy. Maybe I could have tuned that out by raising the rear roll center. If I can't get the car to handle the way I want with the control arms parallel to the ground, I might try that.

[jcox07]

My rear springs are progressive and the car is lowered our setups are not that far apart and yes I am heavier in the front but my car is balanced and I am surprised your car isn't balanced better than it is with what you have done to it.

[jdpeterson21]

Paul,

It's in the CCR Forum: http://ccrscca.proboards.com/thread/658 ... lo-results

I think they threw my times out?

Did my work session. Not sure what happened there.