Hi John,

This is exactly what a Toyo engineer from Toyo Canada said to me when I called them asking about tire pressures. He sent me some really cool technical documentation on the R888 vs. RA1 as well that I can try and put online.

He said, for a car in the 3000 lbs range, that we should be running 40+ psi for better wear. He cautioned that the car will be tougher to drive with that pressure, but wear will be great with similar laptimes (as compared to running mid-high 30's psi).

Like all things in life, there are trade-offs and we need to decide what we're willing to give up

 

thanks FC. Can you be more specific then "40+"? i ran tp's in low 40's F and mid 40's R and it just felt really loose (but i do have a limited point of reference- my old RSA race car on Hoosiers. maybe i'm expecting too much?). i did not have a chance to go down in pressure as we ran out of time.

thanks!

 

Would still rather have cups at 40-50 degrees to be honest (I live in the UK so used to poor weather too!). They do warm up.

I understand why people in the uk use 888s on 911s as they are half the price of MPSC, but for you guys where price is pretty much the same, I just can't work it out! oh well lol. Just my 2p.

 

at 44psi hot in BSR 2700-2750 pounds with driver, it's very easy to drive. i dont feel any difference than when it's at 36psi hot.

 

Maybe in your bsr, that may work.

I spoke to Toyo USA and they told me 2 lbs less then the RA-1s.

 

on my GT3 i have done 36 to 44. feel the same to me. same lap times. but less wear at 44.

when did you talk to toyo? they USED to say that. last i called them, they said low 40's for 3000 lbs cars.

 

so it sounds like their is no secret tire pressure that allows them to wear like 888's but stick like R6's. i was just dreaming.......

 

no, in my last BSR race, the two fastest cars were 8-10 psi apart. with in 3/10 of each other in qual time.

if you are 8 psi off on R6 or mpsc, you probably will kiss a wall somewhere. this R888 is unique in this respect.

 

Here is info from Toyo Canada that is similar to what he said to me on the phone. It's important to note that he said the higher pressures will give better wear, whereas the lower pressures will make the car easier to drive. Lap times will be similar in both situations. For pressures on a 3,100 lb GT3, he recommended 38 to 45 psi HOT.

Disclaimer: I took this from the SPDA website:

Tire Construction change
a. Generally, the R-888 has a higher spring rate than RA-1, meaning it is stiffer

b. More cornering force per camber angle vs. R-A1

c. More cornering force at smaller slip angles

d. Overall wider tire

e. These will affect car/tire setup

RA-1’s Flying Laps

a. Testing shows RA1’s tendency to produce fast lap times at the end of it’s life.

b. If racers are testing worn out RA-1s (corded) to new R-888 (shaved), they may see that the RA-1 is faster in some instances.

* Owning a pyrometer is the best way to tell how a tire is performing.

The attached technical comparison data shows the performance improvements of the R-888 compared to the RA-1 and as you will see the camber does not need to be set so high to achieve similar cornering force compared to the RA-1.

I have attached many files that may help with maximizing set-up.
Let me know if this assists the racers.
Thanks and good luck!

John Carpenter
Technical Services
Toyo Tire Canada Inc.

There are about 10 documents in the .zip file which includes some engineering tests.

Great support from Toyo Tires.

Technical document: http://spda-online.ca/modules/newbb/...&post_id=32700

 

Also found this online a while back, but it may be outdated because it was used for the R888 launch: http://www.grindstonemotorsports.com...esentation.pdf

 

it was last season, so you are probably right.