ProjectR13B

iTrader: (1)

So, I'm planning to pick up a TII by this winter so I'I'm doing a lot of planning now.

I'd like to push around 400 horsepower and plan to mostly use the car for AutoX and track days. I'd like to run on street tires preferably, even though I know I'd be better of running slicks. Or if I run slicks, I'd like to be able to switch out to the same size street tires.

Real question is about size thought. At that power and running mostly AutoX + a few track days, what sizes should I be ok with. I'm thinking 285/35/17s on the back and 275/35/17s on the front, unless it's better to run the same size front and back, or if I should run something that's not as wide.

Also, I did some research but can't really find much on rim strength, but was curious if forged wheels or 2/3 piece wheels would be stronger/better for tracking?

Street rims I wouldn't care because our streets are terrible, but track and AutoX I'd prefer to go with strength/lightness.

Thanks guys

Edit: I am going through the FC wheel fitment thread, but I had extra questions beyond fitment, so I made this post. Also, I know that these wheels are to wide to fit stock wheel wells, especially on coilovers, so I plan to modify+ add wider fenders so the wheels have no fitment issues which the body.

Also, with that tires size, I'd like to be on a 17 inch wheel if possible. I'd rather not go above that, but I'd do 18s if necessary.

MaczPayne

iTrader: (5)

Here's a proven combo to start out with:

255/40/17 front, 275/40/17 rear on Enkei RPF-1 17x9, 17x10 rears

The tire sizes you mentioned are not very common and will probably be difficult to source from most manufacturers.

Furthermore, it would be more economical to run the same size tire all around (275/40/17 x 4).

eage8

iTrader: (9)

the problem with most 17s is any tire that's wider than a 255 is going to get taller (they're 25.7" diameter instead of 25") so you loose wheel travel on the front and can't get the car as low...

most people that run wider tires run 18s because there are some shorter sized 18" tires.

285/30/18 Dunlop ZIIs or Yokohama AD08s are both 24.8" tires, so you get more suspension travel....

and yeah, you'll need aftermarket fenders to fit tires that big, 255s is the absolute max on a stock rolled fender.

lOOkatme

iTrader: (19)

you can fit 285's or 295's on stock fenders. 18x11 +45mm can fit 295's, you can go up to a +40mm 285 width. run -2 degrees camber or so which helps with handling as well.

ProjectR13B

iTrader: (1)

Good to know. I know you can't go wrong with RPF-1s. look decent and are pretty light. thanks a lot. I may even consider 275s all the way around. I'm not sure what a wider front wheel does as far as steering input. Since I'll be running a lot of AutoX, quick input will mean a lot. Part of the reason I plan to keep power steering, though I've never driven a manual rack FC.

My current tire choice is Yokohama S.Drives due to the fact they have decent grip at an economy price. They make a 285 for 17s. But, if I can run 18s and get better suspension travel, I'd really consider that instead.

My major goal is to build a fast car. Right now I'm driving a stock 03 Miata. It's great. I've owned 5 other RX-7s that have all been fine, but I think it's time to move up the ladder some.

Besides, somebody needs to be out at my local events representing the rotary scene haha.

eage8

iTrader: (9)

not on an FC you can't.... I assume you're talking about FDs

I run a 315/30/18 with power steering and it turns just fine. Just make sure you get a wide enough wheel for the tire and you won't have a problem.

They don't make it in a 285/17:
http://www.tirerack.com/tires/tires....eModel=S.drive

and the s.drive doesn't even compare to the top street tires like the Dunlop ZII, or the hankook RS3. I'd rather have either of them in a 255/40/17 than an s.drive in a 285.

just look on tire rack at the tires overall diameter. You want something with 25" or below.

ProjectR13B

iTrader: (1)

Ah. I see. Misread the 19 as 17. And I'd much rather go with a better tire when it's time to build. I'm just I'm running S.Drives now because they are decent for the price.

The issue seems to be finding a rim wide enough for a super wide tire, but I'm sure I'll have less issues when I really get to looking around. I'm still searching for information on the forum to. Just a lot of posts to weed through to get info.

Are you running 315s all the way around, or just in the back? And if you ran a different size front to back, have you noticed a difference in response?

eage8

iTrader: (9)

315s with 18x12s front and back. (Ronin Speedworks widebody)

I used to run a 255/275 stagger and couldn't get rid of the understeer, I'd suggest going with a square setup if you can....

ProjectR13B

iTrader: (1)

Jesus that thing is wide. Looks good though. I was kind of worried about understeer. on thinner tires.

You don't have any issues with the 315s all the way around?

lOOkatme

iTrader: (19)

You want to stretch the tires onto the wheel. This will reduce understeer. putting overly fat tires on not as wide wheels reduces traction.

So

9.5 = 245
10 = 255
10.5 = 265/285
11 = 295

eage8

iTrader: (9)

balance is a combination of a ridiculous amount of things... you should be completely fine with 255 square on 17x9s

ProjectR13B

iTrader: (1)

Cool. May have to try that first on some cheaper rims. Have a feeling it'll be a lot of dialing in. Goal is to find a nice-ish tII that runs first so I can focus on some other things besides the power first. not sure how that could affect me going from stock power to 350-400hp after total build.