Autox competetive street tire vs. RA-1 (or similar) for track use
 

I'm trying to decide on whether to get "R-Compound" track tires should I decide to track either/both my 2002 Boxster S and/or my FR-S. I will definately be autocrossing both, and plan to stick to "street" (>140 wear for PCA) tires for both of them.

It's been years since I've used anything other than RA-1's on track. I'd rather not go to super agressive negative camber to prevent chunking, and (I need to double check the rules) I probably am limited to stock range adjustment for PCA stock rules on the Boxster anyway.

So, I'm wondering if RA-1's are significantly better (primarily in terms of life/consistency, but lap times as well) than the current crop of competitive street tires for track use.

Thanks for your thoughts.

Honestly, the new crop of ultra-performance streeties that are coming out (new Star Spec, BFG Rival along w/ Bridgestone & Kuhmo following suit) are more than likely going to give you 95% of the RA-1 performance.

They should also allow more heat cycles before they give up. Best of both worlds & no tire-changing before/after events!

I agree, the current crop (Dunlop ZII, BFG Rival, and possibly Bridgestone RE11A and Kumho ???) is really good and with long life. In addition you'll have similar response and feedback to your PCA 140TW tires. I always feel like there is an adjustment period when you go from streets to stickies...

RS3 and the Dunlop ZII are the defacto street/track tire. What are your temperature/climate requirements?

The current crop of street tires and those being released in coming weeks are amazing dual purpose tires. The gap between r-comps and extreme performance summer tires is closing at a very quick rate.

unless you're in a spec series or have a specific-setup suspension (not for street) there is no reason to buy dedicated r-comps anymore

especially if you're gonna autocross

because in autocross you're either on a street tire or you're on an r-comp, and if you're on an r-comp it better be a hoosier A6, and hoosier A6s are not for the track.

so stick with the street tire, they have plenty of classes for them now.

So, do you guys run these "street" tires down until they have basically zero tread depth like you would with an RA-1? If so, I'm guessing you must still use multiple tires - one for rain, one for dry?

I run the street tires on my S2000 down to the wear bars or less. No use throwing money away, you paid for them!

If it rains, oh well. Go out and have fun. You aren't going to be setting any new track records in the wet anyways, but you'll learn a lot about your cars handling dynamics and car control.

At an HPDE event, you shouldn't focus on times much anyways, sure the tires may heat cycle and not be *as* fast as they were before, but if they are still gripping, it really doesn't matter in that setting.

And that leads to my concern about the useful life of a street tire. My RA-1's are hitting their sweet spot (in the dry) when they get to the wear bars. Plenty of good days are left between hitting the wear bars and hitting cords.

RA1s are good to the cords. Street tires will heat cycle out. RS3s would be a great dual purpose tire. Just need a codriver for Autox.

We buy the RA1's shaved down to 4/32's, only because TireRack refuses to shave them to 2/32's. :P

Buy yeah, get those damn tread blocks OFF OF THERE!... well, that is, if you want to go fast... on a dry surface. :) And yes the RA1's are good till the cord and sometimes after that!

In the vein of things overheard at the race track: "RA1's are just like other things in life we like a lot... they're better when shaved."


And to think, my car only has 4 wheels! :lol:

http://img.photobucket.com/albums/v8...c/DSCN2682.jpg



Edit: I just realized I didn't contribute any value so I wanted to add this. Get one of the new agressive street tires hitting the market like the new Star Spec. They are supposed to be a very good tire and provide grip without needing to be 180+ degrees F to stick. The RA1 is like any other R-comp RR tire... it's garbage till it's hot.