burglar

So, Porsche Cup takeoffs are pretty cheap, would they be ok for an open track day? I'd like to save my Star Specs for autox duty.

27/68-18, if I'm reading it right, are 270mm wide, 680mm tall, and fit on an 18" rim. That would put them about equivalent to a 275/40-18. That's 0.7" taller than the factory tires. Also, does anyone know if these would squeeze onto the factory 8" wide rim?

Feel free to call me an idiot if necessary.

Razz1

Your not going to get a 275 on a 8 " rim

Boyd

I was running 285/35 Hoosier's on our stock rims at the last few events. They fit just fine.

burglar

Yes, but A6s seem to be designed to be squeezed onto too narrow of rims, thanks to the SCCA. Do the full slicks share this contruction? There is a 24/64-18 as well, which is close to a 245/35-18. Might work better.

I was hoping someone has tried previously heat cycled full slick takeoffs though. My experience stops with R-comps.

ebb

iTrader: (7)

I have run them. Get the 24/64 size for sure. I had some new and some used. They are great tires, better than r-comp dot tires.

TeamRX8

iTrader: (25)

You must not like your fender liners very much

bakayarou ....

ebb

iTrader: (7)

bakayaro? not sure if that is for me, I was not sure what that meant. Urban dictionary says ******* in japanese.

I don't have fender liners.

TeamRX8

iTrader: (25)

Idiot, but it and the overall reply was intended as a joke toward the OP who likely does have fender liners, not you

taller and wider than OE is asking for trouble for a street type RX-8

that siad, I do have a set of 255/40-18 Hoosier rain tires for added throttle control in wet conditions, but then the chassis doesn't see a lot of G loading in that situation

that was on a Stock class vehicle, not sure I could get away with them on my lowered STX class car (which requires 140+ treadwear tires anyway, just a reference point)

.

ebb

iTrader: (7)

I dug this up for anyone who is interested, has all the specs for the tires and other good info on how to use them.

TeamRX8

iTrader: (25)

^^ Good info, thanks

I'm fairly confident that he doesn't have the 5.12 rear gear either. A 26.9" OD is great fro top end, but with the OE gearing will hurt acceleration out of the turns.

.

ebb

iTrader: (7)

Correct, I would never consider the 27/68 size even with a 5.12. They use 24/64 on the fronts, that is what I used. Best would be a 17 inch hoosier slick, 43720, that is an inch shorter (24.3). Combine it with the 5.12 and get the best results. The Michelin 24/64 is 25.3 tall (643mm) so not too far off a stock tire.

burglar

Thanks a bunch guys.

Anijo

Keep in mind, those tires are not R-Comps, they are not street legal. At work, there's a guy who races a 993 cup car. He once said that the jump from R-Comps to full on race slicks was as big for him as the jump between street tires and R-Comps. He's mentioned figures like gaining 14 PSI from cold to warm and that if you hit a curb wrong while they're cold, the tire can pop off a rim.

His name is Jim Walsh, I'll see if I can find one of his mails where he talked about it.

burglar

Just a quick bump, but isn't a 295/30-18 Hoosier A6 a commonly used size on a CS prepped car? R6s in that size are cheap also.

Highway8

iTrader: (11)

If your still looking for takeoffs, pm me. I have been getting the 275/35/18 ga/koni Hoosier and contenentals for $300-400. They fit great on a 9-9.5" wheel with the correct offset 40-45.

My understanging is the GA/KONI takeoffs are a little harder compound then the R6 but will last longer and still be much faster then a R-Comp.

TeamRX8

iTrader: (25)

Not common, but I ran them on stock width wheels and OE springs.

Highway8

iTrader: (11)

Stretching a 275-295 tire onto an 8" wheel for autoX is ok because you want maximum contact patch and sidewall stiffness is not as big of a concern. HPDE or road racing you need that extra sidewall stiffness and that kind of stretch is not recommended.

burglar

Thanks for the input. Are you happy with how the tires perform for HDPE duty?

Another update, I wrote Hoosier about the 275 Koni series tire and this was my response:

When I get off the pot and actually make a purchase, I'll post my experience.

Highway8

iTrader: (11)

I am very happy with the Hoosiers I have been running. I can get them warm fairly quick and they provide very consistant lap times (when my tire pressures are correct). Tire wear has also been very even, a little excessive outside wear on the fronts but I only run a little more neg camber then stock. Kind of a performance street alignment.

I am suprised Hoosier said to mount the 275's on an 8" wheel but it will fit, that goes against the info they provide on their website. It will work fine for autoX, but you will be compromising side wall stiffness and it will hurt turn in. If you could get a 245-255 you would probably have the same or better results and obviously a 9-9.5" wheel would be the best option. Its only money, right???

burglar

Due to the input from this thread I decided to wuss out on the 275s. I grabbed a set of very good condition 245/40-18 BFG R1s for $200 picked up locally. Can't complain about that price.

Now if I could only find some A6 scrubs for a similar deal...