Bias ply road race tires as autocross tires?

I've been thinking about going with bias ply road race slicks on the Abomination and on the new arrival as well. I can't seem to find any info on this, anybody out there have dos/don'ts/hell yeahs/hell nos about going with this setup?

They last longer and tolerate heat a lot better. The side walls aren't as stiff as DOT-Rs, but they don't need as much camber. What class are you running? I think only prepared and up can run them.

I'm running Modified, which allows slicks as long as you run a scattershield and driveshaft loops. I can also get a killer deal on the size I need.

They are very very grippy on grippy surfaces. Many of the CP guys have been trying DOT-Rs instead of the normal bias ply since moving to HPT. The jury is out if it's actually faster.

Down here 99% of what we run is plain old asphalt, it's pretty grippy. The one or two guys who run bias slicks like them pretty well. All the C Mod Formula Ford guys run them. My car will be heavier, but for such a short period it shouldn't overheat them.

My car will be between 2750 and 3050lbs... They are hard to overheat.

Make sure you run the proper compound. Most road race tires will not heat up in the course of an autox run.

That's what I was going to say. A road race compound likes heat before it will stick.

The tires I am planning to use are Hoosier R45's, that's a medium compound. I figure they will take some heating up with the first run(s), much like the V710's I am currently running. There is a 25 and 35 compound as well. A buddy of mine down here used to run Formula Fords in both road race and AX, his take: the soft compounds will work better in the earlier runs but the medium would work better on later runs, since the car is about double the weight of a FF which would cause the tire to generate heat quickly. Since I plan to HC as well, the softer tires could possibly overheat quickly on a long course with a lot of turns.

I'm not sure how the compounds compare but I run the Goodyear GT bias slicks in R250 and it still takes pretty hot days to get them to temp. If the Hoosier numbers are similar I would look at softer compounds if you can. I'm running them on a FFR Cobra replica that weighs about 2500lbs with me in it and 470RWHP. TONS of fun! :)

jth

I would run the R25 compound and spray with water between runs to keep from overheating. I plan to do this on my modified class miata.

I may be talking apples and organges here, but IMO, run Rcomps instead. I'd be really interested to know if anyone is winning at Nats. on slicks, (not being a smart ass; I just have no idea) as the surface has changed from concrete to asphalt.

The only time the old EP car (yes, it was FF and 1580lbs. wet,) had incredible traction was on days close to 100 degrees with two drivers. Otherwise the tires simply never got hot enough. Winter events? Forget it. It was like riding a damned jet-ski if the temps were under 60 degrees. This was on R35's up front, and R25's in the rear. I can't imagine how bad R45's would be. Had I kept the EP car, I would've switched to Rcomps. No question.

I'm no expert. Just sharing my personal experience. Hoosier Tom @ Mid Atlantic Motorsports will talk your ear off, but he does know a thing or two about tires. I'd give him a call.