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Re: Anybody trying to go autocross this weekend?

Posted: Fri Jul 31, 2015 6:41 am
by integra55
steverife wrote:You mean the car that pax'd 49th?
yes … an non pro driver (20 pax when pro's are taken out) … so yeah .. I still say he did pretty well … I didn't say he did great :lol:

and neither am I saying that the BFG's are faster … just that they seemed to do ok in this event

Re: Anybody trying to go autocross this weekend?

Posted: Fri Jul 31, 2015 7:17 am
by steverife
I get what you are saying, but I think tires are generally discussed in the context of "are they they fastest, are they fast enough to beat everyone?" Some national results by Wilcox, Whitener, etc are probably better examples for that argument.

Unrelated to that, but I watched Kuhn's video from this weekend and it was nuts.

Re: Anybody trying to go autocross this weekend?

Posted: Fri Jul 31, 2015 11:22 am
by integra55
understood … guess I didn't make my point … if a pro level driver had been driving his car, I'm pretty sure that car would have been WAY higher up the PAX latter

Re: Anybody trying to go autocross this weekend?

Posted: Fri Jul 31, 2015 1:42 pm
by dewittpayne
lcoleman wrote:All the math and theory in the world won't make up for seat time and real-world proven methods.
Which is why I'm going to Kentucky Sunday.

Re: Anybody trying to go autocross this weekend?

Posted: Sat Aug 01, 2015 5:23 pm
by Miata22
Headin to Richmond this Sunday. Leaving Knoxville at 6am

Re: Anybody trying to go autocross this weekend?

Posted: Mon Aug 03, 2015 11:09 am
by dewittpayne
I was very happy with the handling of the car at the event at EKU after softening the front bar, stiffening the rear and dropping the rear roll center.

Re: Anybody trying to go autocross this weekend?

Posted: Mon Aug 03, 2015 12:24 pm
by John Brown
I don't know how much it would affect the handling... but that's a super small lot, with basically ZERO grip if its like it was 3-4 yrs ago.

Re: Anybody trying to go autocross this weekend?

Posted: Mon Aug 03, 2015 1:32 pm
by dewittpayne
JB,

I didn't think it was super small, about 650' by 300'. The course length was about 1/4 mile with only one crossover. Yes, very low grip, but not that much less than Pelli. And the grip is the same for the front and rear tires.

These are Google Earth images at as close to the same scale as I could get:

Image

Image

Re: Anybody trying to go autocross this weekend?

Posted: Tue Aug 04, 2015 3:22 pm
by dewittpayne
The wider the tire, the more sensitive it is to changing camber. With 335 width tires on a suspension with less than optimal camber control, McPherson strut with the chassis pickup point lower than the suspension point so camber increases with roll and a live rear axle, minimizing roll dominates over weight transfer balance. Thus very stiff front springs and/or very stiff front sway bar and a high rear roll center. My tires aren't that wide, particularly my street tires and my front roll center is higher so camber increase with roll is less. Since this is my daily drive car and it travels most of its miles on 245 width tires, I'd rather have decent handling on those tires rather than try to extract a possibly minimal increase in grip on the 275 Bridgestones.