Initial pressure for R888s
 

I had a great time at the last track day I went to and feel pretty good about my performance however I was pretty occupied trying to get the pressures set up correctly in order to match the wear marks with the indicators.

Has anyone dialed in the initial starting pressure(s) (prior to running) for the Toyo R888?

Thanks :tup:

I shoot for 35psi HOT. Your starting cold pressures will vary based on ambient and track temps, so you will need to experiment on starting pressures. Ballpark for a typical summer day I start at around 25-26 psi cold. On a very cool day, I might start around 29psi cold.

Then as your tires and pressures come up, you can fine tune the grip levels front/rear by altering tire pressures in order to achieve the desired handling balance.

^what he said. also you might want to start at slightly higher pressures than sharif as you might not be pushing the car as hard as him since i dont know your track ability. but the goal is around 35 psi hot so just check them right after your first session and adjust from there.

Thanks both ^

I started at 33 1/2 psi for each tire, at the start of the (~54 deg) day. After my first session I was up to ~38-39. I then let the air out down to 34 psi while hot and ended up adding some air back for my last two sessions (had some yellow flag runs etc). After I drove the car home (20 minutes highway) I was down to 28 psi.

Your information provides additional insight.

Thanks!

The R888 are unlikely any tires I have driven. With the stiff sidewall, the car can run on 30psi without rolling over. Yet somehow the tire seems to work better with pressure between 38-44psi, the car just has more grip with the high pressure. It is odd to say this, but I recommend 38-42 cold pressure on the R888 (a tire which I hate). I think Toyo recommended the same thing.

If you hate the tire I'm guessing that is experienced based? If so what's your story on different pressure setups including temperatures and how many laps before noticed affects etc. => Aiming at were the tires up to temp prior to any bad experiences?

Next time out I'll try "a little" more pressure.

Thanks!

Most people get the feeling that the side is actually a bit softer than some DOT race tires. I get that feeling when driving them. The lighter the car, the stiffer they will feel.

38-44psi is on the high side, but if your setup allows you turn faster lap times, then do it. The stopwatch doesn't lie. If I ran mine that high, I would be slipping all over the place.

The change in tire pressure wasnt noticeable in terms of feel, but I was averaging .5-1.5 sec faster per lap. It honestly doesn't make the car feel any better, but it is faster in my experience with them (on two different cars).

I just don't like them because of the price to grip factor. For the price close to the A6/R6 or R1, they don't even come close in terms of grip/time. On the other hand, the RA1 were slow, but they could last 3x as long. It's all about grip to life to cost factor for me, I just don't see the reason of getting the R888 unless you absolutely need to drive the car to an event and in bad weather. There is a reason why Toyo is re-releasing the RA1......

I was a long time lover of the RA1 on my 350z, then I sold the car and got a C6, I used R888 on it for 2 years, then I moved to a RX-8 where I tried R888/R1/Dunlop street tires.

Compare to A6/R6/R1, of course it is softer. I was comparing it to the RA1 sorry.

As I said before, the car felt no different on low or high tire pressure, yet the times just came down with the higher pressure. I guess that's the reason why Toyo recommends it. I honestly didn't believe it at first as the tires look fine on the lower tire pressure, yet the lap timer didnt lie and gave me the consistent result (lower times on higher pressure).

Actually there was an article on the corvette forum regarding the 888's which I used on my '07 Z. They found that a higher pressure ( 38 and higher ) made the tires work better. They did on my Z, about 39 if I remember correctly. On a very hot day 100+ my times were going down when everyone else's were going up FWIW.

Stan

It's the weirdest thing. Tires don't look any different, it doesn't feel much better, but times improved

This is what I found on the corvette forum:

Toyo R888s Pressure Info - Corvette Forum


Stan

Wow, thanks for the information! This forum is great. Looking forward to the next track day and I will report back.

It'll be good to see what your results are Nikon. Good luck!!

Stan

additional R888 info:

http://www.aimtire.com/typ_category....&ObjectID=6828

Enjoy!