emptnest

I run Nitto 05's (square) on my 1993 Vette, almost exclusively on the track - very few street miles.

This is my first set, and they have about 50% tread left after 6 track days. The 6 days equates to about 24 heat cycles.

It seemed on the most recent two days that the tires lost grip much earlier in the session than previously.

Do these particular tires degrade with heat cycles, and if so, are they past their limit?

SunnydayDILYSI

I haven't noticed much of a degrade with heat cycles. But once I get a track down and run 9/10ths, they will overheat after 4 or 5 laps and become "greasy". Happens even quicker on a hot day. Have to practice tire management to get through a good session.

emptnest

Yes - I have just recently realized that in my pursuit of the fastest lap, I have begun to push my tires to their limits, and losing grip earlier in the session.

While my single best lap time might be highest driving that way, my average lap time probably suffers.

Next event, I plan to back off a little, practice better tire management, and hopefully maintain better grip in the later laps.

Soloontario

Unlike an R compound tire, Nt 05s should handle heat cycles ok, but they can't handle heat.

aaronc7

My experience as well.

emptnest

My last two days were noticeably warmer air and track temps than the previous 4 days.

So my experience fits with these comments.

63Corvette

OK, having run both tires..............
I prefer Michelin PSS tires (for track usage, over Niitto NT-05.
This even includes the cost differential. The PSS sticks better, falls off less, is better in the rain, and costs LESS when averaged over the life of the tire. (I have NO connection with Michelin).

emptnest

Its not a high jack. I'm happy to hear thoughts on any superior tire, and hopefully it's available in 275/40/17.

I dont question that PSS is an overall better tire, but I've never heard them described as less expensive per mile. Especially since most users describe the Nitto 05 as providing long life.

aaronc7

I think the widest 17 for the PSS is 245. I think really your only good options in 275/40 if you want more traction is going to the rcomps R888 or NT01. Hankook RS3 in 255/40/17 is an option as well.

emptnest

Are the R888 or NT01 limited by heat cycles? If so, how many?

Of course, they are also softer, so wear might determine their life as much as heat cycle.

emptnest

I find these 200 wear ratings available:
Toyo Proxes R1R and Falken RT615K.

Any opinions on those?

FASTFATBOY

The NT-05 likes a really low start pressure, 27-28 psi if not they get greasy pretty quick from all the sliding around.

FASTFATBOY

Stay away from an R1R, they are ok on a small car like a Miata.

Falken is ok.

emptnest

Big 10-4 on that. My first couple of days I ran them with higher pressure, and I have the center wear to prove it.

Had it not been for that, and I estimate I would still have over 75% tread left.

emptnest

SunnydayDILYSI

R888 and NT01 have significantly better grip and heat resistance compared to NT05, no matter now many heat cycles. That said, they will also get "greasy" 15 minutes into a session, but not as much as the 05. Trade off is you can't run them on the street. If there is any standing water on the road, they are dangerous. Next step is R7, but those have no rain ability and only have slight fade into a 50 min session (compared to NT01).

63Corvette

Unless your sanctioning organization regulations prohibit this, I would recommend that you upgrade your wheels to 18" all the way around. Do this by purchasing a set of stock 10.5X18" Z06 rears to run on your front wheels. Foremost reason is that there are MORE OPTIONS for track tires available in 18" than any other wheel size!
Your biggest booster of track compitence will be your seat time. Seat time will be enhanced by spending your money on track time rather than on tires and hardware. You can buy and use "scrub" race tires from a Forum vendor at $50/tire to $200/tire. You could also buy a separate set of track wheels and run your 17" on the street and still use 18" for the track, but whatever your choice, 4X18" wheels are the better option for the track.

FASTFATBOY

I bought 2 sets of stock wheels and put some cheap MAXXIS or whatever street tires on the 17's for rain days.

Bill Dearborn

On my C6Z I got 26 track days and a fair number of autocrosses out of a set of NT05s. From a performance standpoint they didn't have a lot of grip after the first couple of laps. However, they were cheap. When I finally dumped them they still had usable tread but were totally heat cycled out. They had no grip whatsoever.

They never performed as well as the GY SuperCar EMTs that came on the car. The EMTs were fantastic after a couple of warm up laps whereas the the NT05s just went from good to greasy very quickly.

They were cheap and they lasted a long time, all I had to do was put up with a lack of performance.

Bill

emptnest

Two questions about the effects of temperature on the R888 and NT01:

I may finish the season on one of these, but that means November temps possibly in the high 40s or low 50s. Will these tires grip (as well or better than a year round street tire) at those temps?

My garage is not heated and gets into the low 30s in winter. Do these tires require warmer winter storage?