r Compound Tire questions & Toyo R888
 

I’ve worn out my Yoko AD08s (Well the backs). They were the best track/street tire I have ever owned. For the record, they were a lot better than the PS2s I had on the car before. I would highly recommend the AD08 for a street/track car.

Now I decided to try the Toyo R888. 19s They are the first r compound tires I’ve owned. My goal for these tires is five 2 day track events (Sebring, Daytona, Barber, Road ATL, Miami)+ 3000 street miles replacing in them in January.

I have a bunch of questions someone may be able to answer:
1) Is the # of heat cycles something real that I need to pay attention to?
2) How many heat cycles can I expect out of these tires?
3) What counts as a heat cycle? Would 2 30 min outings with a 30 min cool down in between count as 2 cycles? Would it be better for the tires to do 1 hour straight?
4) Does any daily driving (Florida heat) or driving 500 miles to a track count as a heat cycle? (Yes I know I need a trailer…)
5) At what temp do they usually need to be to really start sticking?
6) When the tires haven’t gotten up to temp yet, how do they perform in comparison with good street tires (PS2 for example)?
7) When they have “Heat cycled out” how quickly do they drop off? On the track will they still be better than a good street tire?

I've just done four events on my first set of R888 and for some reason a lot of people between this board a couple others hate these tires. So far I love them. Only thing I can complain about is that during long sessions they start to get "greasy" or a little slippery. I'll do the best to answer some of your questions for you.

1. Heat cycles is something you should pay attention to with all R compounds, I'm not sure what most people get out of R888s though. (answer to question 2)
3. A cycle counts when the tire comes up to temperature then cools back down to non operating temperature. If you did an hour long session you would definitely feel the "greasy" feeling I described earlier.
4. I have heard that these tires heat cycle while normal driving, so with 500 miles to the track they definitely will
5. I run mine 36 front and 38 rear, thats hot. Once they get to about 40 they get slippery
7. Havent gone through a set yet so I can't help

good topic...would like to get some more info on tires and heat cycles and personal experience.

Also, for those that are driving to and from the track on 19's the R888 is the only other option other then MPSC as far as r compounds.

I've done a total of 8 HPDE days on my R888s and I rotate after each day and they still look like they could get another 4 days with ease, especially the fronts. I do run more negative camber though.

The R888s handle heat very well compared to other R compounds and the best heat range for them is 180-220 which in some cases can be tough to get to if you don't drive that hard but about 140 they start to get like glue. The first time out they will feel a little squirmy unless you shave them but after the 1st event that is gone.

They drive fine on the street but are noisy compared to a true street tire. I think they are a great bang for the buck but make sure you can dial in negative camber. This is a rule for most DOT track rubber. I run -2.5 fronts and -2.0 rear and with 36-38lbs hot are perfect for me.

I just got back from the Darkside DE event at Roebling and I was cutting 1:23s on them and I was not even hammering her deep into turn 1.

Even at this angle you can see the camber on the fronts:
Attachment 508516

R888 and RA1 toyos, Nitto NT01 are told to use same exact rubber compound. but with R888 there is also different rubber down under that molds upper secction of 'proper' r-comp tread to the tire, so, when you wea them down to wear bars your traction will deteriorate severely as instead of proper compound you will start driving on that other rubber used for mold. So you cannot wear R888 down to cord.

RA1 tires can be corded wihtout loss of traction, same with NT01. Also, first couple of sessions R888 will feel a bit greacy but then it will settle. Just do not think you got true 6/32th worth of tread with R888 and everything will be fine.

trick with R888 tires is to buy them cheap (<$250) and buy them shaved to 4/32th. 3/32th is a bit too much.

Misanors4 and Doc GTO: The hot pressures of 36 front 38 rear, are these for 19s or 18s ?

I've always heard the 19s need a little more pressure.

Just to make sure your definition of hot is the same as mine: In terms of HOT, do you mean I come off the track after a cool down lap with the brakes very hot, rims hot, check the pressure and the target should be 36,38?

See one of the problems I have is dealing with pressure change during a session. I imagine to have 36, 38 hot I would have to go out with around 28, 30 cold. How do the tires handle at such low pressures?

do not start with pressures lower than 26psi or so...
only method on a really hot day is to do a several warm up laps, then do a quick stop at staging and adjust pressure a bit, then continue.

Doc GTO,
R888s have a "left" and a "right" stamped on the tires.
Do you flip lefts for rights or are you flipping the tire on the wheel?
I have R888s and they are wearing well, but I bet it will be time to rotate them soon.
Thanks.

The pressures I gave you are for 19's, and yes come in the paddock after a cool down lap and check them as soon as you get out of the car.

I run the same pressures (36/38) in my 18s with good success.

I usually start at 32 cold all around then adjust after my first session to a hot of 38 all around. That is usually after one cool down and then right to the gauge. I run the 19s. I would think the 18s would be more happy at 36 hot.

My 1st outing with the 888s I ran a hot of 36F/38R but this time I tried 38F/R and it felt a little better and with the new springs I was able to trim 1 -1.5 sec a lap.

Yes, I run the first DE day in the correct rotation and then I rotate side to side for day 2. This way I get even wear. The track I got to the most is more right turn dominant and they get more wear. You only need to worry about the correct rotation in the rain or a wet session. I have not flipped on the wheel yet and I may not have to. The wear is great on these just going side to side and keeping the neg camber.

Thanks.
I'll try that on my next dry weekend.

Rotate without remounting???
 

I am confused. If you have the R888s mounted on a rim the tread pattern is V shapen with the point of the V facing forward. If you rotate left for right and right for left, wouldn't that change the direction of the tread?? To swap sides don't you have to remount with proper tread orrientation?