books

iTrader: (8)

Flyweight,

Base on the following quotes, would you please indicate whether 275/40/17 on an Enkei 17X10 +38 offset requires fender rolling or not?

"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)"


"1. Run a 275/40 17 drag radial. You can fit this on your 17x10 +38 inch wheel with a decent sized fender roll. "

Flyweight

iTrader: (1)

Hello there,

The wheels and tires you purchased will not fit unless you pull the crap out of your fenders and run rubber bands for tires...or run a widebody kit. The purpose of this thread is to provide information for people trying to run the largest tires possible under a stock fd body.

If you want to run the sizes that you mentioned you will need either...

1. Consult someone who knows more about "Hella Flush" fitments i.e. extreme rolled fenders, and extreme streached tires. This "Hella Flush" movement is more about the look of the car and does detrimentally affect the dynamics and functionality of the car.

OR

2. Look into installing a wide body kit for your FD. This is very expensive as you will need to purchase the kit, paint the kit and fit the kit to your car. I personally love the look of a stock bodied FD and would never consider running a widebody kit. I think they are ugly and you can easily fit a 18x9 front and an 18x10 rear on a stock bodied FD. Which leads me to your 3rd and in my opinion best option...

OR

3. Sell the wheels! Silvia or Z car folk would be interested in the size and offset of the Volk wheels that you have. You can then use the money that you recouped to purchase a set of wheels that actually fit and FD. Do your research and don't spend any money until you know exactly what you want.

Good luck!

Flyweight

iTrader: (1)

Whether or not your car needs a fender roll is dependent not only on the wheel and tire but also on your ride hight and the stiffness of the suspension that you are running. That said a 275/40 17 is a large tire and with the relatively low offset of +38 on a 10 inch wheel I will assume that you will need a fender roll to fit the tire properly. How much of a roll will again depend on your ride height and how stiff your suspension is.

Good luck and post pictures of the results!

books

iTrader: (8)

thanks.

CrewDJ

This may be a silly question, but i havent seen it mentioned at all. What would be the problem with runnin somethin like an 18X9.5 on the back and a 17X8.5 or 9 on the front? A guy could have the size and footprint on the back where theres room, and still have a pretty good sized tire on the front without havin to roll the fenders. Any problem with that?

OriginalFake2

iTrader: (3)

Ok, time for a new set of summer tires for my front!

These tires came with the wheels when I bought it and were purchased at 2 different times by the previous owner so the front ones are needing to go.

Front: 235/45/R17 - Bridgestone Potenza RE050 Mounted on 17x8 et35
Rear: 255/40/R17 - Dunlop Le Mans LM702 Mounted on 17x9 et35

The wheels are BBS LM's

I'm thinking about going with a 235/40/17, I would like the same stretch as the rear which is pretty nice. But I'm afraid it won't be enough or any at all? What do you guys recommend?

GoodfellaFD3S

iTrader: (213)

235/40-17 is only 24.5 inch overall diameter, so shorter than stock. I've seen guys use it, but you'll most likely have issue with the front lip scraping in certain instances.

If I were you, I'd consider 225/45 and 255/40---- 25 inch overall diameter evenly matched front to rear. those are also the standard width tires for those width wheels.

Check these out, good pricing and amazing tires for the street: http://www.tirerack.com/tires/tires....t+Z1+Star+Spec

OriginalFake2

iTrader: (3)

Thanks for the advice goodfella, what will the width be like? will it be an even stretch compared to the rear? The front is currently taller than the rear, which I don't like

vr6t3t4

what about a 17x10 et 38 front with an agresive fender roll can that be done?

GoodfellaFD3S

iTrader: (213)

Pretty sure I already answered these questions in my last post...... it should be perfectly even wrt to overall height and also the relation of tire width to wheel width.

on the rear you can run that without a roll at all with 265s. On the front you'd need skinny tires to have a chance at it.

Flyweight

iTrader: (1)

The benefit of running 18s is that you can run a shorter sidewall which improves turn-in/response. 18s are better in the front.

The benefit of running 17s is that a bigger sidewall tire generally has more grip on launch/acceleration. 17s are better in the rear.

That said a 18 front 17 rear car would look rather dumb. A couple of supra track and autox guys run a CCW set up with 18s front and 17s rear for the exact reasons I mention above. Check out: http://www.tunerzine.com/view-article/just-fine

That said t is very easy to find a 17x9.5 wheel that will fit the rear of an RX7.

Flyweight

iTrader: (1)

I am going to have to disagree with Goodfella here on this one.

An excellent option for you would be to run a 265/40 17 rear and a 245/40 front. Unfortunately, these sizes are rather rare. That said, the Dunlop Direzza Sport Z1 Star Spec does come in these sizes and is an EXCELLENT street/autox tire. This would give you much more meat for tires. If I were you this is the setup I would run.

You could also run a 275/40 rear. This would give you many more tire options. Read my posts on the first page about running a 275/40 rear...summary: worse gearing...better traction...more difficult to fit...heavier.

I would not run a 225/45 17 front as Goodfella recommends. The tire is too narrow. If you are checking out this thread you are interested in fitting the largest tires under a stock body RX7. Check out a 245/40. They are slightly shorter than but much wider than a 225.

Good luck!

Flyweight

iTrader: (1)

This is my recommended range for fitting the largest size tires on a stock bodied RX7. Going with an offset lower than what is recommended will require smaller tires...not the purpose of this thread...that said you MIGHT be able to squeez a 255/40 or a 240/40 on a 17x10 +45...maybe...depending on fender roll, ride height, suspension ect.

FRONT
Wheel Width Offset range Ideal
10 +50 to +52 +52
9.5 +44 to +56 +48
9 +37 to +63 +45

REAR Offset range Ideal
11 +48 +48 (will require fender roll)
10.5 +42 to +54 +48 (will require fender roll depending on tire size)
10 +35 to +61 +44
9.5 +29 to more than+60 +40

If the wheel you are thinking about is an Enkei RP-F1 you should look at my recommended RP-F1 fitments on the first page. You will not be happy with a 17x10 +38 in the front if you want a large tire up front.

Josh18_2k

iTrader: (3)

this is the reason for my autox setup:

Front: 18x10 - 285/30/18
285 is the widest "short" tire, allowing the car to be as low as possible wih no fender issues (i might try 295's if i can find em cheap enough)

Rear: 17x10.5 - 315/35/18
315's are $100 cheaper per tire in 17 vs 315/30/18, and a bit cushier for laying down power out of corners.

i dont care if it looks dumb, it works

CrewDJ

That's all good info, however it's not what I asked... My original question was the reverse of what you told me. I would like to run 17s in the front and 18s in the back. I'm not lookin for the perfect setup for racin, I want it to look right. A 1" difference from front to back would look fine with the smaller on the front wouldn't it? It may not be perfect for performance, but it would allow a bigger tire on the back and a fairly big tire on the front without havin to worry about rolin fenders. This car isn't gonna be a track car, it's gonna be a Sunday driver and show car. With that said, any problem with my theory?

Flyweight

iTrader: (1)

Your idea of running a 17in front wheel and an 18 inch rear wheel has been done many times especially by the 240 crowd. In terms of performance...this is not ideal. In terms of style...well that is up to you and not the purpose of this thread.

It is not the wheel diameter that requires a fender roll it is the width, offset, suspension, and overall diameter of the tire that determines whether or not you need a fender roll. You need 25 in tire front. A 255/40 17 is a 25 inch overall diameter tire. A 255/35 18 is a 25 inch overall diameter tire.

CrewDJ

That's a much better answer, thank you. 17s were covered at the beginning of the thread and that will work perfect for me and what I'm wanting. You put it in very good terms for me to understand. I've been haven a hard time gettin my head wrapped around rollin fenders but it makes much more sense now.
Thanks again

GoodfellaFD3S

iTrader: (213)

I provided a link to the Star Specs earlier in the thread, so we're on the same page there.

Wrt to tire sizing on a given rim width, it's my opinion that the sizes you're recommending are certainly an option, but I'm not sure it's a good one.

Why fit an overly large tire onto a relatively narrow rim? You'll get better grip for braking and acceleration, but the car's cornering abilities can/will suffer.

Mustang guys run 275s on 9 inch rears, but i've never recommended it for FDs that will see auto-x, road race, or canyon-run type driving.

Different strokes for different folks, I suppose

Flyweight

iTrader: (1)

There are a few differing thoughts on fitting wide tires on relatively small wheels. Fitting a 275/40 on a 9 inch wheel may not be as ideal as fitting that tire on a 10 inch wheel. The tire sidewall will flex more and you will lose some responsiveness. However, I will refer to autocrossers here. All competitive autocrossers run the largest size tires that they can possibly fit even in classes that do not limit wheel width...and they run faster because of it despite the reduction in responsiveness.

The larger the sidewall the smaller wheel you can run. For example a 275/40 17 generally have a wheel range of 9-11 inches whereas a 285/30 18 generally has a wheel range of 10-11 inches.

I would rather have a 275/40 on a 10 inch wheel but if I have a 9 inch wheel and I am looking for performance I would still take a 275/40 over a 255/40 provided I do not mind the change in gearing/weight.

fd_neal

iTrader: (4)

Is there any reason why a 16x10 offset 50 wheel wouldnt work? I plan on measuring on the car this weekend to double check.
Widening the factory wheels or getting a custom set made are the only options that I know of here. Widening that Ive looked into would cost ~240 per wheel and custom steel wheels im still waiting on prices and weights.

Kumho and Hoosier both make an attractive size 16" tire 265/45/16 25.2" tall and 275/45/16 25.6" tall, that in the real world are probably closer to a 285 in width.

gracer7-rx7

iTrader: (16)

Also keep in mind that running less sidewall generally results in less traction on bumpy surfaces. You do get "better" steering feel b/c of less sidewall but you also get less conformance to pavement irregularities.

Grassroots Motorsports just did a test on a NC Miata testing 17" and 18" wheels on an autox course. The 17" wheels won out for the reason I mentioned above.

Also in their test, running a 245 instead of a 255 on the 17 x 9 wheel resulted in quicker times. IIRC, They felt that was b/c there was less squirm from the 245 on a 9" wheel compared to the 255/40/17.

Flyweight

iTrader: (1)

A 16x10 +50 would work just fine. I have read that Westcraft does a good job widening aluminum wheels. The domestic market (Mustang, Camero, Corvette crowd) seems to have had success with them. http://www.weldcraftwheels.com/index-1.html. That said, the stock FD wheels that are scalloped have been prone to cracking. I do not know how they would do with being widened...Also you will need to very accurately measure where you want your wheel widener to cut and add two inches of wheel to get your +50 offset. This will require a lot of measuring and remeasuring.

Ordering a set of 16x10 steel wheels might be a good option as well...maybe even cheaper. Of course you could go completely custom and nab a set of Kodiak 16x10s...although for a lot more money. Just a few options if you are interested in running 16s.

I would personally run the 265 as opposed to the 275 because of the height of the tire.

Good luck and post your results,

Andrew

fd_neal

iTrader: (4)

Weldcraft is where I got my price from, there are a few shops locally that may be setup to do it but I havent looked in that much detail yet. All the width gets added to the backside of the rim, so adding 2 inches would turn the offset to 75.4 and would need a 1inch spacer to bring it back to 50mm. I was thinking a bolt on 1" hubcentric spacer would likely do the job and still be safe.

The FD rims that crack are I believe 2lbs lighter than the ones that dont. Truthfully I am worried about cracking and flexing the stock wheel with an extra 2" built into it, but its one of those things you wont know untill you try. And 710's are also my first tire choice.

Heard back about the steel wheels, Diamond Racing Wheels. 16x10 back spaced as requested. $169each 25lbs each. Very good pricing, but too heavy for me.

Flyweight

iTrader: (1)

Widening the stock FD wheels sounds like a great project and one I think a lot of autoxers would be interested in. If Weldcraft is not willing to add the extra width anywhere but the outer edge I would try another company.

Kevin Doe widened his Enkeis to 18x11. He added his extra band in the middle of the wheel and has been autoxing on them. This would allow you to run without the spacer...less weight, more safety. Do you have the light verson of the FD wheel or the heavier version?

I am excited to see your results.

-Andrew

3rdgenguy

iTrader: (1)

well open this up agian im going ccw i like to run 255 35 18 up frount on a 18-10 wheel + 48 basiclly i want fit ment like Enkei RPF1 18-9.5 +45 i guess my ? is what offset to run.

for the back i want to run a 285-295 30 18 so a 10.5 or 11 rim again i want it to fit like the Enkei RPF1 18-10 +38 so a 10.5 should be a +44 ?? and 11 +44 ??

thanks
Martin R