PedalFaster

Maybe it's just me, but I have no idea what "AR" is. Having said that, on Hoosiers the consensus is that wider is better; A6s don't take long to warm up at all, and overheating tires is a very real concern. I'm not sure if anyone's done back-to-back testing of 245/275 versus 275/275, though.

CKit

Aspect ratio?

mcsinc

sorry, yes AR= aspect ratio.

Thinking about wider tires for street tire class for autocross. Our local club uses a street tire PAX multiplier for stock classes (0.975). I think this is the direction the SCCA is going with their RT(R/B?) classes. Our lots are small, but typically run 45-60 seconds on rough pavement

PedalFaster

Conventional wisdom is that street tires don't respond as well to "overtiring" as R-compounds do, and thus that you don't want to go that wide with street tires on stock rims. Everyone I know of running an AP2 in RTR is running a 245 or 255 rear tire. There isn't consensus on the right front tire width; some are running square setups (e.g. James Yom), and some aren't (e.g. Ricky Crow).

As for aspect ratios, I don't know if anyone's made a conscious decision there -- James and Ricky are both running BFGs, which don't have a choice of aspect ratio.

Cool hand luke

With the new stock going to street - has there been an update to this that I can't find? I'm trying to specifically find what is the recommended sway bar setup for the new street autocross class. My dad has a 04, running staggered bfg rivals. our two autocross venues are both crappy pavement with lots of gravel.

I read the old threads, but since we don't have near the grip with the 200 tw tires, and the surface is crap, do we need as stiff of a roll bar as what was recommended in this thread?

iamxpl

cant go wrong with Gendron, ARE, Karcepts, Comptech and Moddiction/Saner.

SATXCFP

What is the softest compound allowed for 2015 in BS? STR?

Karcepts

With 200 tread wear street tires, I don't believe you would want any more than a 1.25" OD w/ .25" wall sway bar center section. A solid 1.25" bar or larger OD bar is most likely going to plow too much, even on the softer settings of the bars on the market. I'd start with .25" wall.. maybe even .188" wall if your surface is low grip.

200TW for both classes in 2015.

iamxpl

^^^ he knows what he is talking about. If you are looking for a bar he is the man to speak to.

viccath5

I run the Gendron bar in the size that Karcepts recommends. 1.25" OD, .25 wall with bearing mounts. Our surface sounds a lot like yours. I run it set on 3 of 6, 235s on the front and 255s on the rear. It is just a bit pushy in the front in mid corner. Could probably go down to 2 of 6 but I really like the feel in transition.