"Toyo RR is a really good tire." +1 ....from what I have observed at some of our favorite tracks, 2 seconds a lap. Too bad they don'r make the RR in 18". I'll just have to continue on with my Nitto NT-01 tires. As I continue to harp, 33% less $ than Hoosiers and are in their effective stickiness band for at least 20 heat cycles...albeit a little slower on the lap times.

 

Did you mean Kumho V710? Toyo doesn't make a tire with that designation.

 

"Did you mean Kumho V710?"....sorry, these were the Toyo DOT 40 tires they had about 5 or so years ago. They dropped the complete line.

 

I just started taking tire temps on my Hankooks. What have z214 users seen as optimal temps? I usually aim for 36 psi hot.

 

How heavy is your car? That's a bit high...

 

RRs come in 18, but I think the biggest is 275/35.

 

That's the problem, 275/35/18 is the only size...nothing for the fronts. $285 a tire..If they made a 245/40 for the front I'd be all over it.

RR is the Spec Boxster tire....most of the drivers are 2 seconds quicker compared to the Toyo DOT 100 tires.

 

I would not consider Willow Springs a "banked" track (well, the very inside of Turn 1 and Turn 2 have slight banking), so there is no reason to take out any negative camber when compared to Buttonwillow or Chuckwalla or Laguna Seca for that matter. The reduced negative camber is likely why you corded the tires----unless you usually run the same settings for the NT01s. Does your race shop normally recommend reducing negative camber for WSIR?

Also, adding 130 lbs and decreasing negative camber is not going to help things in terms of outside edge tire wear. . . .

Chris A.

 

Willow Springs isn't a banked track and I'm sure that the excessive Hankook tire wear was due to not enough camber. My car is relatively new to me , set up has been a work in progress and the camber has subsequently been increased. My point is that if you have to decrease the camber at Autoclub Speedway(which is a banked track ) to low levels to prevent tire failure then you're just going to get extreme wear from insufficient camber which itself will contribute to tire failure( which I already demonstrated at WSIR). So R7s and Z214s are not really an option at Autoclub Speedway.The 130 lbs has nothing at all to do with tire wear. It has to do with tire alternatives.If I use less sticky tires such as NT01s, then POC GT class rules allow me to take 130 lbs off my car( though how easy is that to do for just one track?) My point was that my car minus 130 lbs on NT01s wouldn't be near as fast as the current weight on R7s or Z214s. So no great solution except maybe skip ACS and wait for Buttonwillow.

 

Dave , what would you shoot for hot psi for 3000# boxster S ?

Cold starting psi?

Thanks

 

maybe 34-35 hot? 26 cold?

 

I am starting to see issues with John Colliers 993 now that it is running GT5 at 3200 pounds. He always ran 26-28 psi cold at 3000 pounds stock g class weight. The car is now blistering the rear tires in 8-10 heat cycles, especially the left rear and only on the outside edges. It looks like it needs to start 3-4 pounds higher cold with a target of 38-39 psi hot. He has run Hankooks for years and occasionally had issues with the left rear, but it looks like the heavier weight is accelerating the issue.

 

The heavier the weight the higher the pressures needed, just like with R7's

 

Hi Dave - would you have any similar recommendations for suspension set-up? I've also got a ~3000# Boxster S currently running Hoosier R7s, but will be trying Hankook Z214s this upcoming weekend. Anything specific you might suggest in adjusting the suspension for this change? Thanks.

 

Y'know, I'd run it exactly the same to start. Then make careful note of how the car feels when you begin to push it in transitions compared with what you already know: the R7. The Hankook is a lot more similar to the R7 than to the R6.