I've done about 20 HPDEs on street tires, and I'm switching to RA-1s next year. But I'm torn between buying them shaved or unshaved. I'm not concerned with maximizing the grip right out of the box -- in fact I'd rather maximize longevity. However, I've heard the RA-1s are very squirmy when unshaved, and have a tendancy to chunk up.

So what would you folks suggest? I'm used to SO-2s and SO-3s. I don't plan to use the RA-1s in the rain (I'll use my SO-3s for that).

(Stock 16 inch wheels, stock suspension, if that makes any difference.)

 

I had good luck with full tread RA-1s in the 205/50/16 F and 245/45/16 R sizes. Just make sure you heat cycle them correctly the first time, and then take them off your car and let them sit for at least 24 hours before driving on them again.

After that use them on the street for a few hundred miles before your first track event. Try not to be too aggressive at your first track event and they should be fine.

Anyway that's what I did and although full-tread they were NOT as good out-of-the-box as shaved, they're great now with no chunking of the tread.

 

Oh boy, I have to disagree with Gloffer. I bought unshaved RA1s put 100 miles on them and went to the track and it was BAD!!! Take the advice that I ignored from this site and get them Shaved. Gerry

 

yes don't run full tread RA1s unless you expect a big rain. They have far too much tread squirm when they are full height.

-Ry

 

"BAD!!!" in what way?

 

Uh-oh...don't get C3 started on full-tread RA1s...

https://www.s2ki.com/forums/index.php?showtopic=92955

 

I knew there had been other threads in the past, I just didn't find them....

 

I drove with full tread RA-1 (205 and 245-16s) and they are absolutely SCARY at high speeds until they wear down. I would never use them unshaved at the track. I have used them full depth for autoX and if you bump the psi pretty high, they work alright. Trust me, if you only do HPDEs, get them shaved or put 5k street miles on them first.

 

Another datapoint. I know a very experienced track driver/instructor and novice racer who ended up running unshaven RA-1s last year because he needed them quickly and that's what was available. After his first track day on them (stock E36 M3), he came back complaining that he had made a big mistake, and even looked into whether they could be shaved used (no, they can't be). However, after the first couple of track days he thought they were fine.

When I asked him this same question, he suggested that going from street tires to unshaven RA-1s might not be a bad idea, in terms of gradually going upwards in tire performance rather than taking one big step. I don't think he's planning to get any more unshaved for himself, though.... Hmm.

So, reading that referenced thread: Triple-H, what did you experience with the full-tread RA-1s? Were the other guys right or not, in your opinion?

 

As other things I prefer them them Shaved.

Even with the little bit of tread on a shaved set they were a little squirmy for 2 events.