Matt RX8

Anybody running Hoosier R6's on the track?

If so, what cold and hot tire pressures have you found to work?

I'll be running them in 245/40/R18 size.

Zoom4Three

How is your car set-up? Specifically, how much negative camber and which springs/coil-overs/anti-roll bars, if any, are you using.

Chris H

Matt RX8

stock suspension and regular street alignment.

Zoom4Three

I would recommend spending $60-$80 on an alignment and max the front camber before you go to the track, it will be money well spent.

Either way, I would start with cold pressures fairly high for your first session and see how the shoulder wear works out. (42 psi cold, aiming for 46-48 psi hot). This will seem like a lot to many experienced track guys, but you want to error on the high side with the stock suspension or you will burn through the sidewall/tread cap junction in a big hurry. You can always lower the pressures to increase grip, in 2-3 psi increments, as you get a feel for the amount of tire/shoulder wear with the stock suspension, on your track surface and driving style.

Chris H

Matt RX8

Thanks for the advice.

On tirerack, they list the max inflation pressure for the R6 at 44psi (cold pressure). This is much lower than other r comps such as the BF Goodrich G Force R1 which is listed at 51 psi max.

Given that, is it still Ok to start at 42 psi? Seems a little too close to the max.

Zoom4Three

It's common to inflate beyond the maximum inflation pressure in a track/autocross scenrio where you can monitor tire pressure and condition at shorter intervals than a road race. 50 psi on camber challenged, FWD cars, like a Mini is the norm in Solo. Checking wear and pressure more often, rather than less would be perferred.

If you have a 20 minute session, come in after 2 or 3 medium/hard laps and check air pressure and roll over. Starting with higher pressure is safer than too low.

Chris H

chiketkd

iTrader: (5)

It might be close to the max, but on a stock suspension, you'll need the hoosiers to be nice and stiff and not roll over onto the sidewall.

+1 on everything Harvey mentioned -- get an alignment, and run pressures of 42psi cold for your first session and adjust from there. As a STRONG word of caution, if this is your first time running a Hoosier, do not push the car to the limit until you develop a good feel for the tire. The break-away at the limit is NOT like a performance street tire or even a Victoracer or RA-1/R888. Slowly find the limits of the car with each session.

Matt RX8

Thanks. Just wanted to be sure.

Any thoughts on the hoosier vs. the BF Goodrich G Force R1's?

Also would the r comps have to be heat cycled and shaved? For the hoosiers, I was considering having them heat cycled.

As far as driving experience, I've done about 25 track days all in the RX-8.
I'm still on the fence as to whether I will buy r comps or not. Or how much longer I might keep the car for that matter...

chiketkd

iTrader: (5)

Harvey (Zoom4Three), would be a good person to answer this question as he's run Hoosiers and the BFG R1 on his car.

R-comps like the Hoosier R6 and BFG R1 do not need to be shaved, but can benefit from heat cycling. However, Harvey works for the Tirerack, and he would also be the better person to answer this question.

NotAPreppie

No kidding. I autocrossed with a guy who raced his wife's '05 GTO. He ran his front pressures on his rcomps (forget which ones) up into the low 60's for the grippier concrete surfaces.

Zoom4Three

The BFG R1's are more durable and will likely survive more heat cycles before dropping off than the R6. The breakaway is a little more forgiving as well, so they would be my recommendation.

As Chike mentioned, no need to shave the tires as they are molded to race depth. All R-compounds benefit from a gentle, initial heat cycle which the Tire Rack can do or you can do before taking the car to the track.

If you have never driven on R-comps before, beware, they are highly addictive

Chris H

Matt RX8

Thanks again.

And great job at the Windy City BMW club autocross last month at Tirerack. I didn't attend but was checking through the results. You folks were flying in that RX-8 and beat some really good drivers. Was that a BS RX-8 that you were using?

expo1

On this link they have a lower cold PSI
http://www.tirerack.com/tires/tirete...jsp?techid=144 I have the same tires you have and depending on the weather have had good luck starting with those recommendations. During the course of the day you should take frequent temp & PSI readings and make minor adjustments. Bring a notebook to log how the runs went and at what PSI's.