Circuit R compounds

[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.

[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.

[bignate]

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

[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]

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.

[NismoS-tune]

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

[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.

[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.

[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.

[Terrh]

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.

[fwd suck]

My vote is for the NT01s.

+ 1 these tires r maaaaaaad

[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.

[Terrh]

what's everyone running in 2012?


I picked up some 275/40/17 RT615's to use on the street and in the rain on my lightweight/pretty BBS LM's

And some hoosier A6's (same size) to use for time attack.

My "track" rims I haven't weighed but they are heavy. I got some 17x9 chrome mustang cobra rims on the cheap. I figure if I end up bouncing it off curbs a tough cheap wheel is going to matter more to me than a fragile lightweight expensive one.


My experiences with R1's in the past are that they really, really like to be warm and don't work at all until they are.

I've used RT615's on track before in a low powered FWD car and really loved them. Lots of grip, no surprises and very consistent unless I got them too hot, but even then if I backed off a bit they came back.


I bought the A6 (vs the R6) in the hopes that they'll heat up quick for time attack when I want maximum grip after less than 2 miles of driving. I'll post back in here with how it goes after a while.

[support@feastauto]

Have never run the R1's but totally understand where your coming from.

The Toyo R888's running now on the Silvia take a couple laps to warm up, even in chilly Nov. weather. But at that stage they will hold out for a very long time.

[bignate]

Final BFG R1 update

Finally got to use these tires at the last Time Attack event of the year at Mission. The rear tires took too many laps to heat up and they just did not provide the grip to get a fast lap time. My worn out Hankook's provided me with a faster lap time(1:18.0) and there are tons of life left in these R1's(1:18.2). They did not hook up at all accelerating out of the corners. Lots of comments from spectators on my 4wd burn outs looking really cool. To me that just means I am not going as fast as I could be.

Really disappointed in the R1's compared to the Hankook Z214 (C51). For next year I have a line on some super soft C91 compounds. I hope that will get me into the 1:16's.

Could track temp have been a factor this time of year?