Z06 Silver Bullet

At Roebling this weekend I ran three different type of tires so figured I would share with folks.
Weather was warmer each day and times slowed once the day progressed each day.

On Friday Nitto's NT-01's (3/32's left to start and bald by end)
1:19-1:20 consistently.

Saturday- used Viper Racing Hoosier slicks (from Archer)
1:21-1:22
Felt horrible. obviously they were dead even though they had lot's of tread left.

Sunday- Toyo RA1 with about 2/3 life left
1:20-1:21 consistently (and probably about 1/2 second lost due to increased temps).

Learnings:
The Toyo and Nitto after this and numerous compares at other tracks appear nearly idenitical in lap times and feel. Nitto starts at 2/32 less tread depth so if you drive to track might as well get Toyo's for longer life.
Both sets of each I had lasted 28-30 sessions (20-30 minutes each) and about 5k street miles.
Always loved the predicatibility and feel, get slick but gentle at limit.

Used race slicks have been hit and miss. At VIR last year I picked up almost 4 seconds from a pair over the toyo's and that was a 95 degree day when I ran them. They actually stuck so well I ran into issues with them rubbing fenders. This pair was horrible. Felt greasy right away.
Reality check though is they were only $200 for all 4 tires.
I think getting brand new tires but a new compound is out is the way to go (get R5 vs. R6 hoosiers for instance).

I have now gone through 1 full set of nitto's and on 2nd set of toyo's.

FYI they are about .5-1 second quicker then stock tires consistently.

Hope this helps those shopping.

Z06 Silver Bullet

Hoosier R4 and 5 have been consistently about 1.5-2 seconds quicker then the Toyo/Nitto combo or about 3 seconds quicker then stock tires.
I haven't run them yet but judging by eveything I read and see my guess is V710's would be slightly quicke then that.

TooManyIDs

vms4evr

Thanks for posting this. I'm running my Supercars now. Was thinking of Toyo RA1 or the older Nitto R2. I would have thought they would be more than 1 second faster than Supercars though. I guess I assumed 2-4 seconds faster. That's kind of surprising.

Bob 33

I can't provide timing data, but after having used both SCs and several sets of RA-1s, I can assure you that the Toyos will give you a substantial improvement over the stock set up. If you are seeking a cross-over street/track tire, the RA-1 is pretty much the only show in town, and it's good down to the cord without the heat-cycle effects of R-compound tires. The Toyo is a bit squirmy at full 8mm treat, but they keep getting better until they become slicks. If you are driving your car to the track, this is the tire that you want.

Bob 33

Z06 Silver Bullet

Yeah, I don't want folks to think the Toyo's aren't alot better then stock. They defiently are.
They last through the session (instead of 3 laps) and are a solid second faster.
1 second is a hell of alot on a 90 second course. And these were full tread toyo's so assume an extra .5 to 1 second if shaved is my guess.

Bspeed

What sizes were you running if I may ask?

JackH

I have a very worn set of kuhmo 710s that I autocrossed. Thye have been heat cycled to death, but thought I may be able to do a track event with them. Anyone ever see 710s' cord?

Z06 Silver Bullet

The toyo's are 305/35/18 in rear and 275/40/17 in front. Nitto the same except rear is 315/30/18.

Hoosiers VRL's are 305 all around.

JimBacus

Any problems with the Nitto 315's rubbing on the Z06 brake ducts?

(I have R2's and like them very much, but would like to try the NT01)

Bob 33

I run RA-1s in the 18" size, 275 front, 305 rear, on CCW wheels. There is minor rubbing with full wheel lock. I would go with 17" tires front and rear if Toyo made a suitable rear in this size, but they don't.

Bob 33

mountainbiker2

I put on a worn out set for a track day. About 185 autocross laps, plus driven on to the events. It was not worth it. The car handled horrible. I looked at it as a free day of tires. After experiencing no grip, it wasn't worth it.

Steve

Z06 Silver Bullet

Tires rub only at full lock.

No real issues with ducts at all in rear with that size. I have run 18x12's with all of these tire combo's with no rubbing.

305's in front get a little rub.

Tourmgr1

I'm interested in the hot and cold pressure you ran in the NT 01's and also the air and track temp during the runs.
I also run the NT 01's and last weekend at Gingerman they never showed a temperature of more than 105 - 109 deg F. This was coming straight in off a hot lap and measuring ASAP. 1:37 - 1:39 laps. 55-60 F outside temp ...I did not check the track temp but it was a cold greasy track early in the day but got somewhat better later.
They are wearing very well and for a treadwear rating of 100 are fairly grippy and very predictable on my set up. They are a long way from V710's however and I'm probably giving up a couple of seconds a lap using them ....but no trailer so I'll have to live with it.
Thanks for posting.
TIA.

Z06 Silver Bullet

For consistency (but not the fastest laps mind you) with a camber challenged car (read have to drive it to track) I found the following:

40-42 front hot
36-40 rear hot (depending on track)

Start cold varied depending on overall temps but usually 32 or so all around.

Both toyo's and Nitto's gave about the best consistency and tire temp readings at these pressures.

I have run as low as 34 hot and I will tell you lower is quicker but not consistent and without some work. Car is also less forgiving then.

Tourmgr1

Thanks, that's pretty consistant with my #'s. I read that 40 psi hot was what to aim for and it would seem to be true. I tried 32 cold through 36 cold and found that 34 cold worked the best for me on this particular day (cold track). I let a little air out as the day warmed up. I also found 2 lbs more in the fronts helped.
This is a Z06 with 1.9 neg camber front and 1.3 neg rear.
I was very suprised at the low surface temps of the tires, I remember my V700's being around 190-200 F hot ???
Thanks for responding. Good luck.

O.T.A.

Do either of you have any real world data on tread life of shaved vs. full depth Toyos? I have heard that shaving actually extends the life, but what is your experience?

Bob 33

I can't speak to shaving's effect on tread life. I buy my RA-1s with full tread (around 8mm), an issue for a street tire driven in the rain. Although a bit squirmy on the track with full tread, I will accept that for rain performance on track and street. The good news is that they don't chunk at the track with full tread. The "full tread" situation does not last long if you track the tire, where over 90% of my rubber gets left. As the tire wears, performance improves, without notable cycling. I track the tire with more aggressive than stock alignment, but below that idea for this tire. But the RA-1 does not require as extreme a negative camber as some tires to perfrom well on the track. WC cars run the RA-1 shaved as their standard tire. Drivers in this series would be your best source of info about tracking the shaved version, and how to maximize its performance.

Bob 33

xsiveone

So, the 315's in the rear don't rub at all? Do all the 275 fronts rub at full lock? Do you by chance have the DRM duct kit on the front?

Do the 315's in the rear stick out of the rear fender well at all? How is the overall rolling diameter compared to stock? Shorter? Taller?

I'm looking to get a set of one of these tires (NT-01, RA1, 555R2) for street/track use. Having a slightly taller or shorter tire combo on the track doesn't bother me, but I don't want something goofy for street use.

Z06 Silver Bullet

When I used to run American iron the answer was yes with shaving.

You had about same life of wear and about 1/2 second quicker laps times in the dry.