[pickwick]

Last weekend I had my first DE (Road Atlanta) on Toyo RA-1s, after doing many on street tires. I'd been warned that race tires break loose with much less warning than street tires so tried to work my way up to more aggressive cornering.



In hindsight the only place I ever heard tire squeal was in turn 7, the tightest, slowest turn. Does that mean I could have taken all the other corners faster? Should I expect a little warning before the spin/slide? Road Atlanta isn't a very forgiving place for experimentation; three cars left on flatbed trucks and I didn't want to be the fourth.



Also, I was running hot pressures of 41 front/40 rear; is this somewhere close?

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[Eric_K]

RA1's (and Kumho Victoracers) are move forgiving than some other track tires and give way pretty progressively in my opinion. Hoosier S04s, for example, are faster but much more on a edge - especially as the number of heat cycles goes up.



Track tires squeal less than street tires so that is not the best indication of how much speed you can carry. Most likely, if you are not feeling the car sliding some then you are not going as fast as you could. Work up to the limit slowly, you will start to get the car moving/sliding/drifting in the corner. Once you become comfortable with that you won't be so worried about a spin.



I run my RA1s 38-39 hot.



Eric

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[Lemming]

Yep, what Eric said. I find RA-1s to be very forgiving and easy to slide (like street tires) but with more grip. As for pressures, I try to run 39-40 hot.

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[Dave]

I run the RA-1's and target 39-42 hot as well. In my experience, they will howl a little over a more limited range than good street tires. They do exhibit two pitches (much like a street tire) with a gentle high-pitched squeal (good), which rapidly will transition to a lower-pitched howl (bad).



The good news is that you can hear them. The bad news is that the slip angle between the good and bad howl is still fairly narrow.



By way of reference, I had run Victoracers once before. By the time they made noise, you were dialing in a bunch of opposite lock to catch the errant end of the car.



My old Michelin MXX3's (great street tire for track) would squeal politely over about twice the slip angle range of the RA-1's, according to my seat-of-the-pants g-force acceleration meter.

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[mikew968]

I ran RA-1's for the first time at my club race. They are very progressive and are easy to save. They like a fair amount of slip angle and need to be driven aggressively with some sliding to be at their best. I was told to target 39-41 psi and set front and rear the same. I was starting with shaved tires to 4/32.



If you have full tread tires they will take a couple of de's to be at their best.





Mike

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