Shoptalkforums.com

Hey guys, I'm looking for some help with picking a tire size for track use. I live fairly close to Sonoma, and I bet my roommate that if my bug can beat his tracked out m3 around the track, he had to sell it.

Anyway, I picked up some new wheels with bad tires, and I'm able to fit the old 275-40-17 rear and 235-40-17 front tires under my fenders with plenty of clearance. I'm thinking of using toyo ra1/r888, Michelin pilot powers, or other streetable sticky tires. But my worry is that my car will be too light to keep heat in the tires.

The car is a 66 bug converted to IRS, big brakes, polyurathane bushings, sway bars, jdm wrx engine with ~280-300hp to the wheels, bus tranny etc. my plan is to go mid engine this winter so I can run a 5/6 speed Subaru tranny and get some weight over the front. Also building a much more powerful engine - however I may only turn it up for drag stuff.

Currently I'm running some 275-60-15 drag radials rear and little 185-50-15's front, but I've mostly been having fun launching and drag stuff, not really cornering since the little tires like to under steer.

I'm open to doing auto-X but my main goal is Sonoma, thunder hill, and Laguna.

Any suggestions?

maurice wrote: ↑Sun Oct 22, 2017 10:25 pm I bet my roommate that if my bug can beat his tracked out m3 around the track, he had to sell it.
Any suggestions?

Yes. Don't give the German's 50 years to design a much better performance car and then challenge a track prepped example to a race.

If he doesn't respond directly, read though some of FJCamper's threads. He posts of wealth of information and insight. Below is one, there's others in STF too.

http://www.shoptalkforums.com/viewtopic ... 1&t=127619

It looks like his attached photos have fallen victim to Photobucket though.

dlamyle wrote: ↑Mon Oct 23, 2017 5:11 am [quote=maurice post_id=<a href="tel:1254998">1254998</a> time=<a href="tel:1508736338">1508736338</a> user_id=40042]
I bet my roommate that if my bug can beat his tracked out m3 around the track, he had to sell it.
Any suggestions?

Yes. Don't give the German's 50 years to design a much better performance car and then challenge a track prepped example to a race.
[/quote]

Lmao, I told him that long after I decided I wanted to screw around on the track. At least I make about the same power he does with a little less weight...

I'll keep digging around. Some of the threads I've read limit their size because they're doing autox, the class they race in, or just physical space.

It's not just the heat, it's the extra weight, no point chasing fractions of a percent with wider tyres if you've just added 10lb of weight in the worst place possible.

Its also the foot print, the tire's material, the type of tire, the rim to foot print ratio and how the sidewalls are affected by the whole mix.