Auto-x, slicks & tire temps

[mtimney]

How wide do you think you should go for slicks when you're running about 280hp? I would assume that slicks would be harder to heat up than high performance DOT tires on an auto-x course?

[7thgear]

when you say "slicks"

do you have a particular tire in mind?

[mtimney]

Originally Posted by 7thgear

when you say "slicks"

do you have a particular tire in mind?

Something like a Hankook Ventus Z214...about a 40 UTQG rating.

[jprice130]

Originally Posted by mtimney

Something like a Hankook Ventus Z214...about a 40 UTQG rating.

The Z214s come in a soft and a medium compound. The soft compound will reach optimum temperature more quickly, so that is your best bet for the short runs in a typical AutoX event. They will heat up just as quick as most "extreme performance" street tires (i.e. Dunlop Z2s, BFG Rivals, etc).

As for tire width, the Z214s pretty much only come in 225, 245, and 275 widths for 17" and 18" wheels. Generally speaking, wider is usually better in AutoX (assuming you have proportionally sized wheel width), so you could consider 275s all around if you have the wheels and suspension/alignment setup to make it fit.

With that said, have you ever competed on r-compound tires before? If not, then you might want to consider starting off with 245s so that you can keep fitment more simple. A 245 r-compound tire will still provide LOTS of grip and will likely be more than you can take full advantage of if you don't have a lot of experience with these types of tires.

Hope that helps!

[mtimney]

Can this car get a 245 slick hot enough in a short run...even with the soft compound? I 'just' manage to heat up my 215 pilot super sports now (at 190hp).

[jprice130]

Originally Posted by mtimney

Can this car get a 245 slick hot enough in a short run...even with the soft compound? I 'just' manage to heat up my 215 pilot super sports now (at 190hp).

I have personal experience with 245 Hoosier A6's (same tire class as Z214s) on my stock FR-S and on a Lotus Elise (2000 lbs/155 WHP). I have run both cars in ~45 degree weather on 50-60 second courses. Even in these conditions I never failed to get the heat I needed. The first run wasn't the best, but by the 3rd and 4th runs, the tires felt great.

Unless you're running in near-freezing temperatures and really small courses, I'd be very surprised if you weren't able to get your 215 Michelin PSS's up to a good temperature by your 3rd run. If you're worried about getting enough heat in 245s, you could always have a co-driver for your car. I'm sure a lot of folks would love to drive a 280 HP BRZ on r-compound tires!

[mtimney]

Thanks jprice!