Sleeper_08

I've given some thought to using the NT555RII as my "Summer" tire but the only size they come in to fit my rims is 285/35/18 which has a diameter of 25.91 which is about 1 inch less than my 285/40/18s. This means the car is going to sit about 1/2 inch lower, which is good, but might be a problem on a DD that is already lowered about an inch. I'm also concerned about the effect on my speed in gears as this would force me to go into 5th at Mosport.

The NT01 come in a 275/40/18 which is 26.65 which is pretty close to my present 27 but I'm not sure they would be a good idea as a "summer" tire.

If they would just make the NT555R11 in 285/40/18 then that would be my choice for next year!

giantkaiser

Why not try the Nitto NT-05 ?

I've heard good things about this tire and it would work much better on a 'dual' car (Street/track). I'm most likely to get these as my next set of tires.

Sleeper_08

Thanks for the suggestion but I'm not sure there would be much difference between my KDW2s and the NT-05, as both are street tires, to have a noticable effect in my lap times.

Philostang

My R1Rs are 26" in dia., and I'm lowered about the same as you (rocker panel to ground is around 5" at front and rear). Around town I haven't had any serious problems with them. I do have to give new found respect to parking curbs, as I seemed to hit more than usual when I first got them. Also, I can no longer make it up my Rhino ramps w/o a boost (but I have a Classic chin spoiler; I don't think this would be a problem on an undressed bumper).

5th gear at RA this year was pretty much useless. So if I wanted a max top-speed effort, I had to stretch 4th on the front straight (nothing too terrible, just held it a bit more than I would have if I had a usable gear to go to).

Best,
-j

Norm Peterson

They may be both street tires, but the NT-05 is a bit further up the food chain.

It's more of an SCCA Solo "Street Touring" category of street tire, so think midway between a top-shelf but true street tire and R-comps. 7.2/32" tread depth and "200 treadwear" vs 10/32" and 300 for the KDW2's. A 200-treadwear ST tire will out-grip a 200-treadwear pure street tire (but won't outlast it).

I think the NT-05 has been discussed in the Street Touring forum at SCCAForums.com.


Norm

Philostang

Since Norm brought it up, the treadwear on the R1Rs is 140 (the lowest I've found in an officially advertised "street" tire) and has 8/32" tread depth.

I got them as my "summer" street tire, but I'm tracking them for this year as the dedicated set of wheels/tires won't come until next year. Fortunately, I no longer drive on the street enough to worry much about how long they'd last under daily duty.

Best,
-j

EdwardGT

FWIW I think Sport Cups have an 80 treadwear.

Sleeper_08

Philostang

My avatar is an old photo and I am now also running the CDC Classic front spoiler. Your comments about running 26" tires on the street are appreciated.

I've already asked my Dad to make me a short ramp from a 2 x 10 to be able to get a kacjk under the back so I know what you mean.

This leaves the top speed in 4th as my only concern because I am already running at full revs (6,250) at the end of the Mosport straight, 133.0 to 133.5 mph. We can see from the data that shifting to 5th is the pits - again confirming what you saw. With the smaller diameter stickier tires we would be on the limiter faster and longer. H'mm there is always the option of a six speed conversion

Sleeper_08

I agree Norm that it may a bit higher up but I was looking for something near the top of the food chain that can still be driven on the street. If I had the money and a place to store it the answer is a trailer and dedicated track rims and tires but living in an apartment makes it somewhat more of a challenge. Also for an old guy like me (60) swapping 4 heavy wheels and tires at the end of a track day before going home is not a nice thought.

What is needed is to win the lottery so that I can then go and buy a GT2!

giantkaiser

I'd say just go for the NT-01's and be done with it.

When i had my Griggs setup fox mustang years ago i drove around on the street with 275/40/17 Yokohama A008-R's and it was a grip monster. I did not drive it often though, and i dont think i would do it if i drove it daily.

When the tires wear out, just get new ones!