Geoffrey

What camber settings are you running. When I was testing the Hoosier Cup slicks on my car, we found them to be sensitive to camber settings and used less camber than a comparable Michelin. I did not have any issues with the Hoosier tires when run at the lower camber and a hot pressure of 30-31.

jakermc

Hoosier took delivery of my failed TWS tires and consulted with PST on my alignment settings to ensure that everything was in order. That story ends with Hoosier replacing all of my failed tires under warranty without admitting or denying fault. Draw your own conclusion. When I ran at TWS this year it was on Michelin tires.

The tread separation I had on the Ferrari was different. I typically go out at 24/22 cold (front/rear) and the tires were run at Sebring and MSR, so no banking involved. I finish hot in the 30-32 range in the rear. Tire size is 305/645-18. Rear camber is a little over the Hoosier recommendation at -2.7 degrees. Problem is if I run with less camber, then the outside edge cords after 4 cycles. Pyrometer, longevity testing, and the stop watch have proved my settings to be superior to what Hoosier wants me to do with camber.

What I dislike about Hoosier is that they always blame the set-up. They tell you where to set-up to avoid blowouts and ignore the other implications of doing so. How about that recommended 40 psi cold tire pressure in the tech bulletin? Good luck with lap times doing that! lol

Spartan

3.4 front and 3.0 rear. Car was always 25 ish cold and between 30-32 hot. This was last Sat when the heat index in ohio was well north of 100

Matt Romanowski

IMHO, if you guys are going out with 20-24 pounds of air in a radial tire, you are asking for it to blow. The rest of the setup doesn't matter, you've already started to damage the carcass. Radials will degrade with that low of a pressure. Now, if we're talking bias ply tires, hell, I've put cars on track with under 18, but that is a very different situation.

jrgordonsenior

Matt it takes 20 cold to keep it under 32 hot in a sprint race and that's filled with Nitrogen. A cup (or cup clone) with a wing easily builds 10-12lbs in the outside rear during a 30 minute sprint. As I stated previously, I usually run stickers in qualifying at 24 cold and then bleed them down which eliminates the starting out at 20 cold. I won't be doing that again anytime soon....

Matt Romanowski

I don't have a 996 or 997 to have experience from, but that seems like too much pressure build if you are running nitrogen. Is it dry nitrogen - not all is created equal. Where the tires bled to be dry and free from air before filling with nitrogen?

24 starting is still low but doable if you are taking it easy until they build some pressure. If it's working for you, then keep doing it. You're results show you are doing thing right!

Veloce Raptor

Nope, not with a full slick...

Matt Romanowski

Slick or tread don't matter. It's bias vs. radial. The tire construction itself is what matters.

cstreit

FWIW I saw some significant cording on the inside of my rear tires a few weeks back. Contact hoosier and sent pictures and the response was that it was likely low pressure. I was running 31-32 hot rear pressures. Running very similar camber settings to the original poster.

R80 Front, R100 Rear....

JoeMag

Chris -- What was your starting pressures? ...also, how many heat cycles to get to the cording?

jrgordonsenior

Well I hope it's dry, it's from Air Gas here in So Cal. Always drained completely then bled twice so it should be fine. Cups (and clones) with large wings transfer tremendous pressure to that outside rear tire....

cstreit

Joe,

I wanna say it was around 20-21... I think I need to target about 34 hot. No idea on heat cycles as this was my first set of R100's on the new car. I managed to cord a new set of R6's in 4 heat cycles though.. What?! Yeah....

Veloce Raptor

I think you'll find that this is contradicted by real-world results from folks running full slicks on Cups and other cars...

Matt Romanowski

And the drain spins opposite in Australia. Everywhere I've driven that applies. It has nothing to do with the car, it has to do with the construction of the tires. There is a reason that Hoosier, Michelin, Yoko, and anyone else that makes radial track tires tells you to run 25+ pounds in them. If you look at Goodyear set up sheets for bias plys, you'll see 18+ pounds recommended. But as always, YMMV.

Veloce Raptor

ooooh-kaaay...