M758

R888 are molded to 6/32nd tread depth. The RA-1 are 8/32nd. In 944 spec we would shave the RA-1 to 4/32 to reduce some of the "break in" time for the tires as used on our cars. One reason this was effective was the that 8/32 tread blocks would shift and give soft response until worn down. The R888 has less thread depth and much larger tread blocks and as such should be fine at full depth. I suspect thay will be fine in DE at 6/32 for even heavy cars. We would run the RA-1 at 38 to 40 psi hot on our 2600lbs race cars. I suspect the optimal pressure for the R888 would be slightly different (possibly lower) given the reported stiffer construction. Even so I think 38 sounds right to start with on street car.

Veloce Raptor

Michael, make sure you get the R888's shaved to 4/32 or so. They will last MUCH longer, are interchangeable side to side & directionally that way, and grip right out of the box w/o tread squirm, very similarly to RA1's. As you know, I have run RA1's in my car for as long as I have known you. You know how my car responds/feels/sounds at the limit. Figure it will be very similar on the 888's. I can give you some suggestedd tarting pressures for TWS and MSR and ECR that have worked for me, but Bryan is right--you should be able to feel what they are doing from that point forward.

weneversleep

VR, thanks for the suggestions. Unfortunately, the tires are already shipped to me, and they're unshaved. But, from what I've read, the R888 are different from the RA1 in that they don't need to be shaved in order to have the same tread life, and because of the shape of the tread, there isn't nearly as much tread squirm.

Of course, this is all anecdotal, and I haven't actually tried them yet.

Have you ordered yours yet?

Veloce Raptor

No, since I buy WCTC take offs, I have to wait a while for (a) some take offs, and (b) some top-tier set-up advice. However, a good friend who races at that level has told me they SUCK at full tread.

M758

One 944 spec racer did a test of these and his full thread R888's were just as fast as shaved 4/32 RA-1's. IN fact he was able to set one very good lap on new R888 that are similar to old worn RA-1s at their best. Of course this is on a 2600lbs 944 spec car.

Adrienne

Dave - I'm about to buy RA1s and drive to the track on them. Do you suggest I shave them even though I'm driving to the track? I figured I'd wear them down a bit just getting there, and I have such a hard time cutting off rubber that I could burn up myself! I'm German, we're practical, I can't help it!!

Veloce Raptor

IMO they are fine to drive to the track shaved....except it if rains.

TR6

I've heard this before. Can someone explain the mechanics of how starting them shaved makes them last longer? I'm not doubting it, I just don't really understand it. Is it based on the assumption that the full tread will "chunk" off? I'm running RA1's at full tread depth. 4 track days on them so far.

M758

If this is your first set of R-tires I would leave them full depth. This would make the transition easier from street tires. I have only run RA-1's on my 2600lbs 944 and never considered shaving for DE use. Since speed was not at a priority I would always advise full tread RA-1 for 944's. I on suggest shaved tires for those looking to race and improve the out of the box performance. On a 2600lbs 944 shaving did not change the overall life span of the tire.

I am not sure if that applies to a 3000lbs 993 however. I suspect that unless you are pushing them really hard which a first timer to R-tires would not be doing you should not have any issues with chunking even on a 3000+llbs car street car.

JackOlsen

If full-tread tires generate too much heat, it can lead to the tire chunking up and getting so soft that the rubber wears off faster, usually on the outside shoulders. This has a lot to do with the weight of the car. On a lighter car, you'll have a longer tread lifespan with full-tread tires. On a heavier car, it can be just the opposite.

Another factor is how hard the tires are getting used. If you're racing, you're going to put more heat into your tires than a typical DE driver would. When I drive a student's car, I'm not pushing things too hard by my own standards, but it will typically put a lot more heat into the tires (and brakes) than the student is able to do. The track you're driving is also a factor. Some courses are much harder on tires than others. If you're not destroying your street tires out there, you probably won't have to worry about the R888's coming apart, whether they're shaved or unshaved.

I've raced on shaved RA1s and on unshaved RA1s, and I didn't see a lifespan change. What I did see was a huge difference in the way the RA1s handle the first four or five heat cycles when they're not shaved. But that might not apply to R888s at all, since the three things that made unshaved RA1s so unruly (soft sidewall, thick tread, 'busy' tread pattern design) seem to have all been improved on in the R888.

Toyo recommended shaving with the RA1, but didn't with the Nitto NT01. What's the official Toyo line on shaving and the R888?

M758

Our Toyo Motorsports dealer told us (944 spec guys) that the R888 does not need to be shaved. He is in direct contact with Toyo so I am sure he got his infor from them. It does however remain to be scene what the best way to use the R888 will be. I do believe that some of this will be car specific. I personally have no plans to shave my R888 when I start using them, but I may find that the hot pressures that are optimal for my 944 may be different than RA-1's. I will not be the first one in my group running these on a 944 spec car so I will be able to take some of the things they learn and apply them to my car.

Veloce Raptor

I have a funny feeling that, to get the most out of them, the WC teams will shave them just as they did with the RA1's.

And yes, the reason for shaving is to minimize the tread squirm and the resulting heat/wild gyrations of inflation pressure/over-heat cycles that result.

weneversleep

Well, mine will be unshaved, so I'll report here how they are unshaved. Of course, what do I know... I'm just a little ol' DE driver getting excited for his first time on race tires next weekend...

In any event, I shouldn't be going fast enough (at least to begin with) to affect long-term durability of the tire. Once I get comfortable with them, hopefully the tires will be worn enough. Plus, I now plan on driving to/from the track with them, so that will accelerate wear anyway.

Adrienne

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M758

Well I beleive they will too. Still that does not mean DE drivers or even club races will want to do the same thing. For us any driver using a Toyo is going to be more interested in speed over time vs pure speed. Gaining .2 of second only to turn the tire into a 1-2 heat cycle tire is not going to happen in DE and is not going to be that common in club racers either. Heck most club racer won't be able to see a consistant 0.2 change in lap times anyway. Too much lap to lap variation.