FamilyCar

Getting down to the wire. I have to decide it I want to try to stuff this up front or not. I know from other posts that others have fit 245/45/17 in C2, but I'm curious about this particular tire. Thx.

FamilyCar

http://www.nittotire.com/tires_nt01.asp

jimq

I had Nitto's on my car when I bought it. My right rear shreaded with about 50% tread left. It looked like it had a bubble on the back side and just came apart. Luckly I wasnt going fast. The tires were good in both wet and dry.

C4Russ

I got to ask....Why?

That is a larger tire then exists on a 2007 Carrera. The new 911 is heavier, faster and more capable then our 964's. What is it that you hope to gain?

If you do manage to acheive a higher grip level, at what cost will that be? Since nothing is free and all that force must go somewhere, you may encounter unusual and unwanted side affects. It would seem that a more balanced car would be a faster car vs. a car that is simply running big *** tires.

FamilyCar

C4Russ, I hope to gain more grip. You are right, "Big *** tires" alone aren't enough. btw, Nitto NT-01s are another DOT legal track tire.

I should give you some context (I was hoping to just ask a simple "Will it fit question"). The RSA I have is a track car, street legal but uncomfortable on the street. Here in northern California I plan to run PCA time trials, NASA TTs, maybe ARC which has 13/13 type rules, and assorted DEs. Currently the car has MPSCs 225/45/17 and 255/40/17 and PSS9s. This off season it's being lightened and I hope to get under 2750lbs. So from a power to weight perspective I'll give up some to a 997 Carrera S, but I'll be close enough. But I don't think there's much point in comparing a track set up to a street car w/ street tires; I know I didn't explain the focus of my car. Also, this off season, the suspension is being upgraded to Moton Clubsport dampers, ERP bits all around: front A-arm monoballs, rear spring plates, rear trailing arm monoballs, ERP front Camberplate, rear monoball shock mounts. Car has Jongbloed 7.5 x 17 fr and 9.0 Rr, though I may change the front to 8.0 x 17

In doing some research on RL, 245s up front and 275s in the rear don't seem unreasonable. I've seen 245/35 18s on 9" wheels and 285/30 18s on 10" wheels used (larry herman) and a 245/40/18 front on a 8in rims and 275/35/18 on a 9.5 inch (K964) - track set ups. Correct me guys if those numbers are wrong. Bruce Anderson in his book recommends 235/45/17 on 8.5 x 17 in front and 275/40/17 on 9.5 x 17 in the rear for a narrow body C2s.

So, if I want more mechanical grip in a tire that gets to optimal temperature faster than the MPSC, then a wider Nitto NT-01s is a reasonable pick. It's got a RA1 like compound, but stiffer sidewalls. It also basically turns into a slick w/ 2 circumferential grooves. With then NT-01s my choices appear to be..

front tire: 235/40/17 or 245/45/17
rear tire: 275/40/17

I have the most concern about the fit for the 245/45/17 in front. Nitto lists 245/45/17 as having 25.55in inflated diameter 9.72in overall width

So, if anyone has experience fitting the 245/45/17 NT-01s please let me know. It'll save me some time, thx.

911skb

FamilyCar,
Did you ever find out a definitive answer to your question? Do 245/45/17's fit up front, under a narrow body 964?

Cupcar

I was wondering exactly the same thing.

I have Toyo RA-1's on the front of my car in 235/45-17 size and Toyo specify them as having a 9.3" cross-section on an 8" rim, but I have them on an 8.5" rim so the cross-section is really 9.5" with these rims using the rule of thumb 0.4" increase in section for 1" of rim width. These tires clear no problem.

My car has rolled fender lips, 2.6 degree negative camber and the 8.5" front rims have 50.4 mm offset.

It looks to me that the 245 Nittos will work on my car being only 0.42" wider.

Nitto show the 245 as 9.72 on an 8" rim, on your 7.5" fronts rims the cross-section of the Nitto 245 would be ~9.72" - 0.2"= 9.52"- essentially identical to my 235 Toyos on my 8.5 inch rims.

The rest depends on your fender lips and negative camber.

FamilyCar

Ken,
I don't have a definitive answer yet. Car is presently at TC Design getting the suspension rebuilt. Tony at TCD said to try the NT-01s in 235/40/17 first. In the rear I will go w/ the 275/40/17 NT-01. For the rims, I suggested, as a starting point, the racing cup car wheel dimensions used in the 1992 season:

Front: 8.0 x 17 52mm offset
Rear: 9.5 x 17 47mm offset (actually 68mm offset w/ 21mm spacer)

I told TCD and Jongbloed (Ryan) to go off their measurements and spec the rims as they see fit.

I'll know more in a week or two.

=========================

Cup,
Thx for the input. I've got Rennspeed fiberglass fenders up front now. Well see. I am mystified by published tire dimensions. You might not find the 245 NT-01s to be "Just" 0.42" wider than the 235 RA1s. NT-01s look like the "Run big" like MPSCs. I will post some pictures. You'll see what I mean.

Thanks,

Pat

FamilyCar

Here are the published dimensions from the tire companies...

Tire Size Section Dia. Rev/Mile

Toyo RA1 235/45/17 9.3 25.4 834
Toyo RA1 255/40R17 10.2 25.1 828
Nitto NT-01 235/40/17 9.49 24.4 851
Nitto NT-01 245/45/17 9.72 25.6 813
Nitto NT-01 275/40/17 10.91 25.6 813

sorry can't get this to format in a table

FamilyCar

Left -- 235/40/17 NT-01 unmounted
Center -- 255/40/17 RA1 (yes) mounted on 8" cup1s
Right -- 245/40/17 NT-01 unmounted

FamilyCar

Closer view:
Left -- 255/40/17 RA1 mounted 8" cup1s
Right -- 245/45/17 NT-01 again unmounted

I don't know if the pictures help, I just know that the difference in width side by side is negligible to the eye.

Cupcar

You really meant to type:

Left -- 235/40/17 RA1 mounted on 8" cup1 wheels
Right -- 245/45/17 NT-01 unmounted

Didn't you?

Cupcar

Also are the tires pictured 235/40 or 235/45 RA1 tires?

The width spec for the 235/45 RA1 is 9.3" on an 8" wheel (Would be around 9.5" wide on an 8.5" wheel)

The width spec for the 235/40 is 9.6" on an 8.5" wheel

C2speed

resurrecting an old thread. How did the 245s ever turn out on the front. I'm actually worried as much about the diameter as the width. Any rubbing?