Suggestions on r compound tires for HPDE appreciated.

Having trouble finding brand and size that work.

Currently running 245/40/18 and 275/40/18 P Zero's. Good track tire but considering something with more grip.

 

Toyo RA1s. Linear feel, communicate to the driver, pretty grippy, good wear rate for an R-compound.

 

Just switched over to these. Get to try them out at T-Hill on Thursday. Can't wait!

 

Did you get full tread or shaved?

 

Full tread since it's winter. I'll replace with shaved once summer comes around.

 

Thanks. Wondering, with a diameter of about 25.5 on the RA1 vs. 26.8 on the OEM, how handling, ABS, etc. would be impacted?

 

If you still have tread by then...

I bought at full tread, and swapped the tires on the rims to even out the tire wear. After 7 track days + 2500 miles, I've pretty much burned off the tread blocks. I figure I'm only half way through the life of the tire...

 

No noticable impact on either despite the different rolling circumference (since the RA1 only comes in a 275/35R18).

 

Good to hear. Hopefully I'll have 5-7 track days on them by the time summer rolls around.

 

A048

 

I ran 25.7 diameter for 5,000 miles with no obvious difference except for gearing. My last set of R tires was 24.7" diameter on all four and again, just gearing differences.

 

Has anybody tried the new Dunlop Super Sport yet? The price and longevity is right, but I hear the trade-off is a little less grip over the competitors.

Michael.

 

I know somebody running a set of Super Sport slicks on a very fast RX7, and he told me they tend to break away a bit abruptly. I was thinking of trying them since a Dunlop guy quoted me a VERY good deal, but I have several more track events left on my current RA1s...

 

Tire Rack has them on clearance, but most of the good sizes are gone. Last time I checked the 265/35R18 was the closest I could find. For $130 bucks though it's a steal.

 

Well just got back from the track- first day on the RA1's. Good thing I didn't have them shaved. It rained most of the day and the track was wet and extremely slick for the first two sessions. I finally lowered my tire pressure to 28 psi in the rear and the car performed much better. Last session was semi dry and the tires performed beautifully. I'm hoping to hit another track day in December which will hopefully be dry

 

Are R compound tires suitable to use on wet tracks?

 

What's the pressure ratings on these tires?

That's sounds WAY low. Typically in any r-compound tire I run, it's near 40psi.

These some oddballs that have an incredibly still sidewall?

 

I did not shave mine so they are suitable for wet conditions.

28psi was my starting (cold) pressure. RA1's can go as low as 18 psi (cold) for RWD cars. Recommended starting minimum (cold) is 22-24 PSI for wet conditions.
41-43 psi is the goal (hot) for dry conditions. Unfortunately it rained most of the day and 41-43 (hot) was way to high to provide any sort of traction in these conditions.

 

I think it depends on the track conditions and which tires you are using. The general opinion for autocross is that unless there's deep standing water, the Hoosiers are better in the wet than street tires. The Hoosiers have ZERO tread, just two 1/4" wide grooves in the middle. People use the Kumho Victoracers (R Compound) for rain tires.

On a big track, you see both. My former boss runs with the Porsche club and again, unless it's really coming down and there's a lot of standing water or deep puddles, he runs Hoosiers.

And it depends on which R Compound it is too. A Yokohama A032R has pretty decent grooves in it. I used them as street tires for a while and there were pretty good in the rain. I imagine an RA1, A032R, A048 or Victoracer are all ok in the rain.