I'm about to get a set for DD usage and a Texas Mile run which (I hope!) will require a Y-speed rating.

Currently the car is on 17x8.5 +40, 17x9.5 +40 TE37s with 255/40-17, 265/40-17 StarSpecs (W-rated).

Wheels/tires fit very well, but I need to roll the front fenders (rears already rolled).

For DD and for the Texas Mile, I'm figuring to run skinnier tires.

Based on the excellent wheel fitment thread, I'm pretty sure that 17x8 +35, 17x8 +45, and 17x8.5 +40 will all clear the StopTechs. Feel free to confirm or refute this if you have direct experience with these fitments!

Ditto for 17x9/17x9.5 RPF1's over 99+ FD rear brakes.

I'm thinking of going with 17x8.5 +40 front, 17x9 +35 rear RPF1s with 225/45-17 front, 245/45-17 rear Michelin Pilot SuperSports.

Or 17x8.5 +40, 17x9.5 +38 with 225/45-17 front, 255/40-17 rear Dunlop SportMaxx TTs.

Or possibly 17x8 +35, 17x9 +35 RPF1s. (+5mm more scrub radius up front not really desired, though)

Or maybe 17x8 +45, 17x9 +45 (might look too sunken-in)

Anyway, just looking for thoughts/feedback, particularly on wheel fitment with SToptechs and 99+ rear brakes.
tia...

 

I am not sure if they fit over the stoptech brakes or not but one wheel size that I always liked was the 17x10" front and back Volk CE28N +45MM offset. Run a 255/40/17 front and rear. Thats what I would run if you stick with 17's. They have the concave face and a huge lip....I think they look great. You can also run a 275 width tire in the back if you want....but I would run the 255's all around.

 

Do you have the wheels already?

I have a set of rear RPF1's for sale. 17x9.5 + 38 with a 275/40 tire if you're interested.

 

I saw your ad, wheels look great, but I need Y or (Y) rated tires, Nitto 555s are W-rated, same as the StarSpecs I have now.

 

I tried the Stoptech template on my old RPF1's. IIRC, the 17x9 +45's weren't close to fitting and the 17x9.5 +38 interfiered with the reinforcement ring behind the spokes. Other members have used Stoptech's with 18" RPF's, but I would avoid the 17's unless someone has a confirmed fitment.

 

9" or wider 17" diameter RPF1s have the flat face, won't fit over StopTechs.
8.5" or narrower 17" RPF1s have a convex face which reportedly clears StopTechs.
See post #3 here: https://www.rx7club.com/suspension-w...ide-fd-892901/

I provided the StopTech template to Enkei and they confirmed that 17x8 +35 or +45 will also fit over StopTechs.

I'm 90% certain I'm going with the following for Texas Mile and DD usage:
17x8.5 +40 fronts with 225/45-17 Michelin PSS
17x9 +35 rears with 245/45-17 Michelin PSS

 

I am not sure if you want to run such skinny front tires...you will be stopping from high speeds. You should look at what others that are running the Texas Mile are running for tires and tire size as your requirements are very different than tracking/autoxing.

Taken from my thread on fitting large wheels/tires...

Option 2: Enkei RPF1
enkei.com
~$300 per wheel

Enkei RPF1s are extremely light and inexpensive. If you are even thinking of purchasing RPF1s you should contact AutoRND (Rishie) from this forum. Expect to pay around 300 per wheel. The downside of the RPF1 is that you can not fit a 10in wide RPF1 in the front of an FD unlike the other options. You will also need to consider if you want to run Stoptech brakes with your wheels or not as some of the fitments will not fit Stoptechs.

RPF1 fitments that work without destroying your fenders with tire recommendations:

Conservative 17 in set up that will fit Stoptech brakes:
17x8.5 + 40 Front (Will fit Stoptech brakes if you are thinking about them in the future)
17x9.5 + 38 Rear

Allows you to run a 255/40 17 in front
Allows you to run a 275/40 17 in rear (note the change in gearing that a 25.7 in overall diameter wheel causes)

Aggressive 17 in set up that will NOT fit Stoptech brakes.
17x9 +45 Front
17x10 + 38 Rear

Allows you to run a 255/40 17 in front
Allows you to run a 275/40 17 (note the change in gearing that a 25.7 in wheel causes) or 295/35 17 (will probably require a fender roll)


Conservative 18 in set up (I would assume that this would fit Stoptech brakes but I don't know)

18x8.5 +40 Front
18x9.5 +38 Rear

Allows you to run a 255/35 18 front
A allows you to run a 285/30 (less acceleration grip due to less side wall but more lateral grip) or 275/35 (more acceleration grip but less lateral grip) (note the change in gearing that a 25.7 in wheel causes) in the rear.

Aggressive 18 in set that will fit Stoptech brakes:

18x9.5 +45 in Front
18x10 +38 in Rear

Allows you to run a 255/35 18 or a 285/30 18 (not recommended by tire manufactures but many people have been running a 285/30 on a 9.5 in wheel without problems) front.
A allows you to run a 285/30 or 295/30 (less acceleration grip due to less side wall but more lateral grip) or 275/35 (more acceleration grip but less lateral grip) (note the change in gearing that a 25.7 in wheel causes) in the rear.

Fitments that allow you to rotate wheels from front to rear:
18x9.5 +45 Front and Rear (Will clear Stoptech brakes)

Allows you to run a 255/35 18, a 265/35 (taller than 25 in overall diameter…be wary), and a 285/30 (not recommended by tire manufactures but many people have been running a 285/30 on a 9.5 in wheel without problems)

17x9 +45 (Will not clear stoptech brakes)

Allows you to run a 255/40 17.

 

Why skinny(ish) tires for street and Texas mile (in order of importance):
1. less aero drag (Cd difference of .01 ~1mph!)
2. less unsprung and rotational mass
3. less $$$

I still might even go with 215/45-17 fronts on 17x8s...

I don't foresee any issues hauling it down from 180mph in the 1/2-mile provided after the traps, that's only ~.4-g stopping, and aero drag will be doing a lot to whoa the car at the higher speeds (.18g at 180). Not at all worried about good 225 or 215 street tires. I would be more concerned about the brakes, but they're 332mm StopTechs so no worries

Not a lot of Texas Mile FD tire info out there...
Quick search shows one guy running a 440 c.i. LS7 ran 275/35-18 NT01s a few years back.
Optimal tire sizes for the standing mile are definitely going to be different from track/autoX, which will favor wider tires much more. Over a standing mile, grip at launch is almost irrelevant, particularly since max speed is the goal, not minimum E.T., so super-wide tires aren't really warranted at the back of the car, either. Narrower tires should give a *slight* aero advantage, but even a *slight* aero advantage should pay dividends for this kind of event.

On the outside chance of a tail-wind, I want to run tallish tires. 255/40s could have me upshifting to 6th and costing a couple of mph. 275/40-17 and 245/45-17 were therefore the rear sizes being considered. Tire availability also plays a big part in selection, hence I'm probably going with the 245/45 Michelins over the much heavier and less sticky 275/40 Sumitomos.

That does mean going with 17x9 rears instead of 17x9.5. Still somewhat undecided on rear offset. I was thinking +35, now I'm thinking +45 to tuck them inside the bodywork a little more. Hmmm...

Great thread, mucho appreciated!

To confirm: I am OK with 17x8.5 +40 RPF1s over StopTechs up front, right?
Based on input from Enkei, I look to be OK with either 17x9 +35/+35, or 17x9.5 +38 in back over FD RZ rear brakes.

Again, many thanks!
Dan

 

If you haven't done it yet, get the template from Stoptech's website.