Circuit R compounds

[Willis]

Bought a set of RE-11 265/35R18. Rave reviews of the tires everywhere I look so I thought I'd give them a try. I do drive my car on the street so a good track/street tire was a must.

[Marke]

The A6 will heat up faster and provide more grip than the R6 but will over heat quite quickly. The A6 gets greasy when it gets hot. You need to get your fast laps in early.

That's how the time attack format works though - one warm up lap, 2 "hot" laps, 1 cool down. Not much chance to overheat the tires.

Time Attack with CACC doesn't work that way. You have a 20min session to throw down your fastest lap. Plenty of time to over heat the tires. Most of the fast guys run the A6 and usually get their best times in the first 4 laps or so. In auto slalom/autocross, on hot days guys running A6 spray them down with water to keep them from overheating.

Bought a set of RE-11 265/35R18. Rave reviews of the tires everywhere I look so I thought I'd give them a try. I do drive my car on the street so a good track/street tire was a must.

RE-11 are a great tire, you will love them. We really have to start a new thread for street tire cause this thread is for R-Compounds which is any tire with a tread ware lower than 140.

[Terrh]

Marke, thanks for your input. The more I read about the A6 the more concerned I am that I'll overheat them, especially with my driving style and the power/weight of my car.

So what's a good tire to pick for a heavy, fast car that gets driven hard? I don't mind trading cold grip in exchange for longer life and a larger slip angle. I wonder if someone makes a good 17" hard compound slick that's available in a size that fits the R32.. (like a 275/40/17 or something).

It seems like the R32 is quite tail happy on throttle which doesn't bother me one bit, but does ask a lot from the rear tires, especially on a road course.

[NismoS-tune]

I thought R comps and slicks were drivetrain killers (stock gearbox and stuff), obviously I have no proof, it's the net.

[bignate]

I thought R comps and slicks were drivetrain killers (stock gearbox and stuff), obviously I have no proof, it's the net.

Well if you launch the car frequently, then yes they can be. By installing high grip tires you move the weak point in the powerflow to the road away from the tires and into the drivetrain. If you are on the circuit its not going to add that much additional stress to the drivelline but I'm sure there would be some due to having more traction.

[Terrh]

Every time I've broken a trans it's been 3rd gear without any sort of wheelspin on shitty tires.

Also, who cares? Faster breaks things.

[bignate]

agree'd. Never shy away from better tires because they are single most effective performance upgrade, PERIOD.

[GTR-Dad]

Drive train integrity depends as much on minimizing shock loads as it does on how much torque, power, or speed you run. If you look at gear design equations you'll see that an intangible called 'service factor' is a direct (and fairly substantial - memory says 1.5 - 2) mulitplier on load. In other words, if you drive like a bonehead, you'll break stuff way more often than if you're smooth.

If you launch your car, take up the drivetrain slack before applying serious power. If you run on the circuit, use smooth throttle, steering, and brake inputs. Shift like your main objective is maintaining balance, not trimming a tenth of a second off the straight.

[Marke]

^^^ I like how you put that. Smooth is faster on the track and easier on the drive train.

Back to the topic of R-comps, Doug Wind runs an SRT-4 at major time attack events through out the US and beats Dodge Vipers. He has used Hankook Z214 C91 and Hoosier A6. He said the A6 has the highest ultimate grip levels but doesn't last and give no warning before they let go. He said the Z214 was very predictable even over long sessions. He only uses the A6 at NARRA time attack events where they pay a contingency for using Hoosiers. I am getting some C91's for the Canadian Time Attack Championship this year. It will be held at Mission on June 30th and July 1st.

If you want the life expectancy go for Z214 C51 or R6.