Let's Talk Track Tires - 2024 Edition
08-20-2024, 02:46 PM
#301
For those of you who have tracked Cup 2 R tires, what are your starting cold pressures and optimum hot pressures? This is the first time I've tried the 2 R; they are much less expensive in stock sizes now than they were a year ago. I was surprised to see Michelin's recommendation of a minimum of 29 psi cold and between 33 psi and 39 psi hot. I'm guessing these tires are similar to Hoosiers in that they require a fair amount of pressure to achieve desired stiffness. I bought a set of Cup 2 Rs to mount after the current set of Hoosier R7s; will probably run them at Thunderhill in early October.
08-20-2024, 05:22 PM
#302
I had a chance to take the Labrat to Buttonwillow on CRS V2 265/305. 19x9.5 front and 19x11 rear. Mixed reviews on the CRS as well as compared to the Goodyear SC3R's. Maybe I was expecting too much. The car was PLANTED on the Goodyears, but the CRS were very loose. I did not spin, but even with multiple shock changes I was fighting the lack of rear grip. It was also a pretty hot day. Having it loose though riverside which is a very high speed sweeper isn't awe inspiring. The Goodyears just wear so quick, but not sure these are my solution. I know they can now do an 11.5 rear with a different tow link bolt, and then do a 325 rear. That may be the solution. (Or just Goodyears ;')
Overall grip was down quite a bit as well. I'd say several seconds between the two tires. ;(
Overall grip was down quite a bit as well. I'd say several seconds between the two tires. ;(
I switched from 3R’s for the same reason as you and it took my brain a track day or two to adjust back to the lower performance of a 200TW tire.
08-20-2024, 07:38 PM
#303
Good to hear more feedback on the CRS’s. They’re not in the same class as the SC3R’s so it’s not surprising to hear your comments. I’m curious to get your perspective when you wear the crs’s down a bit.
I switched from 3R’s for the same reason as you and it took my brain a track day or two to adjust back to the lower performance of a 200TW tire.
I switched from 3R’s for the same reason as you and it took my brain a track day or two to adjust back to the lower performance of a 200TW tire.
The CR-S's already come with only 7/32nd tread depth, so once you get rid of the release mold and get just a little time on them, they shouldn't take as long to "come in" tread squirm wise.
Like you said, what he is probably feeling more is that transition from a 100TW to a 200TW rated tire.
I have never driven the SC3 R tire, so I do not know how it is sidewall stiffness wise to the standard SC3, but I know that the standard SC3 has the stiffest sidewall (other than maybe the RT660) of all other 200 TW rated tires, and the SC3R is probably no exception in its class. So with the CR-S, you probably have to run an additional 1 or 2 PSI of pressure to get an equal feel.
I can even feel that with my AD09's. Even though it is the stiffest sidewall 200TW tire Yoko has ever made, it still isn't as stiff as the SC3, so I need to run about .5 to .75 lbs more PSI to have an equal feel laterally.
Last edited by TRZ06; 08-20-2024 at 07:41 PM.