Tire pressures for the track?

[HawkeyeJim]

Hey folks, new (to me) R8 owner, grateful for this forum.

I'm taking mine to Road America this weekend (May 7-8). It'll be the first time I track something other than a 911 (I've run a 996, a 996 GT3, and a 997.2 C2S).

I searched, maybe I missed it -- but for those of you who track the R8, what pressures have you found to work well for the stock Pirelli's?

Thanks,
Jim

[MotherTucker]

Aiming for the factory suggested pressures when hot is a good place to start. The key there is "when hot". Pressures go up by 5 to 8 lbs when you get the tires hot. This makes the tires balloon a bit which reduces the size of the contact patch which lowers the grip.


You'll probably find that if you are pretty aggressive (up near the edge of grip in the turns), you'll get some initial understeer. If you want to reduce that, lower the front pressure down by 3 (to match the rears) or even down 3 more to 33. This will increase front grip a bit, while slightlly increasing sidewall flexing.

If you are not very aggressive, then the factory specified pressures are fine. Just be sure to keep them there as the tires get hot.

mt

[mngolfer]

Last weekend I ran 30 in the front and 32 in the rear...cold. When tested hot they were 38 hot front and 36 rear. This made a very big difference in the handling of the car.

[HawkeyeJim]

Thanks guys, I'll give that a shot.

Funny thing, tire pressure. The R8 has a rear weight bias but higher pressures in front. The 911 has somewhat more rear weight bias, and significantly higher pressures in the rear (39F/44R from memory). For tracking, the 911 likes hot pressures of only 34F/36R, IIRC.

[harrison]

Recomended hot pressure for Hoosier R6 is 37-41.Then you start reading temps across tread to get an even temp across. When outside edge of tire shows higher temp you can adjust accordingly.This is when a pit crew comes in handy to check all four tire temps quickly when in the pits after some hot laps without the cooldown lap. A tire chock is useful to eliminate car from rolling.

[desperado]

@Harrison and all: Hoosier has revised their hot pressure recommendations for the R6 tire down by 4 psi. The information shown on their website is [still] out of date:

From: XXXX@Hoosiertire.com
Sent: Monday, April 19, 2010 6:51 AM
To: [desperado]
Subject: Hoosier Tire - Tire Care Tips

[desperado],
Thanks for writing and for pointing this error out as the TCTR6_A6.pdf is the most recent update to the Tire Care Tips. The PDF information was never transferred over to the "Webpage" which will be done shortly.

Please follow the air pressure recommendation on the PDF at this time until we update our "webpage".

Hope this helps and I really appreciate you pointing this website error out to us. It will be corrected shortly.

Sincerely,
XXXXX
Product Manager
Hoosier Racing Tire Corp.
65465 US 31
Lakeville, IN 46536
www.hoosiertire.com
P - 574-784-3152
F - 574-784-2385

CURRENT/CORRECT

TIRE PRESSURE RECOMMENDATIONS FOR COMPETITION

Traditionally, Hoosier tires have often required higher pressures than other brands. This has changed with the A6/R6.

Roadrace/track applications
VEHICLE SIZE RECOMMENDED HOT PRESSURE COLD PRESSURE
1800-2200 LBS. 30-33+ 22-27
2200-2600 LBS. 31-34+ 23-28
2600-3000 LBS. 33-37+ 23-28
OVER 3000 LBS. 34-39+ 23-29

+Higher pressures will improve the performance capability but will require a more sensitive feel to take advantage of the increase.

One characteristic of the tires is the tendency to “skate” initially (when inflation pressures are correct). It is important to resist lowering the pressure to attempt to eliminate this feeling. Dropping the pressure too far may improve the “feel” of the tire however it will also lower the performance and increase the wear rate.

OLD/OUTDATED

Tire Pressure Recommendations For Competition

Traditionally, Hoosier tires have often required higher pressures than other brands. This has changed with the A6/R6.

Roadrace/track applications
Vehicle size Recommended Hot Pressure Cold Pressure
1800-2200 lbs. 34-37+ 26-31
2200-2600 lbs. 35-38+ 27-32
2600-3000 lbs. 37-41+ 27-32
over 3000 lbs. 38-43+ 27-33

+Higher pressures will improve the performance capability but will require a more sensitive feel to take advantage of the increase.

One characteristic of the tires is the tendency to "skate" initially (when inflation pressures are correct). It is important to resist lowering the pressure to attempt to eliminate this feeling. Dropping the pressure too far may improve the "feel" of the tire however it will also lower the performance and increase the wear rate.

I'm sure that you have already figured this out on your own by taking tire temperatures, examining the tire's surface, and evaluating the car's handling!

[harrison]

Thanks Desparado. So, for a starting point, (on the heavy as heck R8), 34-39 hot and 23-29 cold. Thank-you Sir.