Track adjustments

coyled · #1 (**permalink**) 03-07-2005, 12:18 PM

I spent Friday at firebird west with an instructor, Ross Thompson. Saturday, I ran at PIR. Ross is a former Bonderaunt instructor and Trans am driver. I learned many things about car control from Ross. With him driving, I was holding my breath at first. Ross helped with the chassis set up. I thought it was pushing on entry and continued pushing. Ross said the entry is fine its a mid corner push. We added rebound in back, some rebound in front , less bump in front and slightly less bar in front. The cobra is way better now. I would not have known the adjustments to make based on my feed back. The cobra now uses the front tires as we have finally got some forward bite in the car. The front slicks look like they have been used finally. On Saturday, PIR was wet in the morning. By the last session, the cobra was quicker than ever. Other than the fact that my auburn is out, so there was no off the corner traction, it was a great day. The funny part is, my arms are not pumped any more when I get out of the cobra. I learned to not fight the car on turn in any more. Faster, smoother and more fun now. Driver still needs the most work. Ross has a web site for those interested in instruction, www.rossthompsonracing.com. Scott

RACER X #99 · #2 (**permalink**) 03-07-2005, 04:37 PM

Scott,
Proof once again that no matter how much track time you have their is always somebody out there that can teach you something new.
So far I have not found anybody in my area willing to get in my car and show me some new ideas.

All I hear is "your nuts for driving that thing"

I did have one of my friends jump in for a ride(an experienced Cobra racer) "this thing is scary" was his responce.

In need of a good instructor,
RD

601HP · #3 (**permalink**) 03-07-2005, 07:01 PM

Coyled,

What does it mean and how do you achieve "slightly less bar in front"? I'm guessing anti-roll bar?

David

coyled · #4 (**permalink**) 03-08-2005, 08:42 AM

Cranky, I was holding my breath a little with Ross driving, very fast but in total control. This was at the west track, short and technical, no high speeds, under 100 mph anyways. It had to be scary for him to ride with me, he has guts to do that. David, the sway bar is adjustable, it has 5 link adjustments 3/4 inch apart from each other. We changed the link or effectively lengthend the arm 3/4 inch. This softend the front a little bit which helped eliminate the mid corner push. Scott

BPWilliams · #5 (**permalink**) 04-19-2005, 09:34 PM

Hey Scott,
Question for ya... I ran the fastest lap times after installing the strut bar in my car on the East track, I also changed my shock setting to the softest that I have ever run. The car was hooking up like it has never before and I dropped 8 seconds from my time. The question is: What would happen if I went even softer on my shock settings? Can you go to soft and have adverse effects? I was looking at Cecil Walkers photographs (you are in there also) and noticed quite a bit of leaning on my car, I am sure it is not bad as long as the shocks do not bind?
Thanks for any input..

Also first time on the track I was the last car to get an instructor and he said not to go over 80mph on a 2.33 mile track (borring) next session I requested a lead follow with an instructor much better for both of us.

Brian

Clois Harlan · #6 (**permalink**) 04-20-2005, 06:15 AM

Scott,

How about posting some pics of your front sway bar and link adjustment settings. That was something that had been suggested to me by Scott Stephens Owner and instructor at Hallett. Dean Lampe and I plan on taking our cars in to his shop for some static evaluation using his four corner scales. He has already driven my car and wanted to put it on the scales before he suggested any further changes.

Clois

RACER X #99 · #7 (**permalink**) 04-20-2005, 06:50 AM

Clois, Good Idea scaling the car before any major changes. We did mine this past winter after I noticed my car handled much better with my 240 lb. nephew in the passenger seat. Needless to say my car was way out of balance with just me in.
Don't forget full tank of fuel and your or your equivelent weight in the drivers seat when scaling.

Good luck,
Roger

coyled · #8 (**permalink**) 04-25-2005, 08:23 AM

Clois, if I have time, I will take pictures and post them. I would scale your car, align it, and check the bump steer. I saw the end of your bar and it would need to be modified for different links. You basically change the length of the lever, longer takes away spring rate and shorter adds spring rate, but only in roll not bump. The sway bar is a good adjustment tool. If you can't adjust it, adjust your spring rates to balance the car. When you are in a steady state corner like the carousel at road america, the balance is all bars and/or springs, not shocks. I would set it with a little bit of under steer. My wheel rates in roll, which includes the bar(not the spring rates) are in the 335 area in back and 375 area in front. This is pretty stiff, maybe too stiff for you but can give you an idea. Last thing, adjustable shocks can help control the transitions, I recomend them, great tuning tool after the spring rates and bar are close. Scott