Leigh2

While we're after Nitto it would be great to have a 255/35 for the fronts as well, or at least a 245/35 instead of the 245/40 that they make now.

deputydog95

My hoosiers have smaller overall diameter compared stock tires. But maintain same diameter difference front to rear. The way I understand it, it's not so much the overall diameter, but the comparison between front and back.

GreggT

Old thread....sorry.
But since there was a fair amount of discussion on NT01s here.....I thought there might be some here w/help on this question.
Can anyone give me tips on what's been found to be good track pressure on these?

I've traditionally run Sport Cups......and I'd start those at 25/28 (F/R cold) and hot they'd be around 32/33-36.........NT01s are a totally dif tire.........appreciate any suggestions.
TIA

4porsh

"I'd start those at 25/28 (F/R cold) and hot they'd be around 32/33-36"

That will work depending on you set up and driving style.
I start out at 25f/25r cold.

GT3DE

performance (race) tires work better on a properly setup car when the front and rear pressures are the SAME when HOT. And the lower the better so as not to wear out the middle of the tire (which is also why drivers complain that the grip is good for the first few laps then gets greasy - that is really just the tire overinflated and overheating).

Mvez

Talked to a Nitto rep today, and he said that a correct 35 aspect ratio rear size is in the works for the 997, but he could not give me any info about a release date. He said that all the requests have been heard, and they plan to release a tire for us. Of course I will believe it when I see it....but encouraging news nonetheless.

deputydog95

IF they ever do it, it will probably be next year. I'm going to run their 245/315 in the meantime.

Mvez

Yeah, I'd be shocked to see anything this season.

utkinpol

be brave - try out 275/315 and report here if it causes PSM to throw CEL or not. i think it should not.

or you can buy 335 RA1s i still have, no one picked up that set.

mojom3

I am running the 245/315 NT-01 on the track with no problems so far. Two days at NOLA on the long track without any issues, but they are still new to me on this car. I too start at 25/25 to end up at 32-34 range. I am worried about when the rears wear down, will ABS be an issue. YMMV

Mvez

That's my concern. Even if it works fine, I still prefer the handling of a bit taller sidewall.

When I spoke to the rep today, I asked him if it would be OK to run the NT555RII rear tires (305-35-18) with NT01 fronts, and he said it can be done, but the NT555RII isnt' quite as grippy as the NT01, obviously. I'm wondering then if the 555RII is similar to the RA1 in terms of grip. The NT01 is faster and stickier than the RA1, I know this for a fact. I'm thinking I might try this combo out, to bridge the gap until the "supposed" release of the correct rear size. Fortunately, I still have 4 pairs of rear RA1's....

Mvez

The NT01 sidewall's are slightly less stiff than the RA1, so when cold, try not to abuse them, or else you'll get more outside edge wear. Just be patient and build up the temps for a lap or two. Regardless, it's a good idea to flip them at some point.

BlueJay73

Here's another piece of the NT01/R555II question. I asked Nitto if the rubber compounds in the NT01 and R555II were the same. Says Nitto...

After doing some research, the rubber compounds for the NT-01 and
NT555RII are similar but not exactly the same. We understand your need
to find the right size tires, but we don't recommend mixing different
tires front and rear due to potential adverse changes in the vehicle's
handling characteristics.

Please contact us if you have any questions.

Thank you,
Nitto Technical Department

-----Original Message-----
From: NittoTech
Sent: Tuesday, July 10, 2012 11:18 AM

masmole

Aren't NT555R and R II's drag radials designed for straight line traction for competitive drag racing? I would think that they're construction and side walls are not designed for the rigors and lateral forces from lapping road courses. Does anyone know of anyone that actually put a set of NT555Rs to the test at any DE events?

BlueJay73

The 555RII's are designed for road course racing.