BlackRX7Turbo

I know of people that have 235's up front and 275's in rear (with 17" wheels) and they drive them that way on the street. I've seen cars on the track, though, with 275's all the way around on 17's.

For the track, is there anyone that puts smaller width tires in front compared to rear and likes it that way?

If there are already threads on this, please let me know - I really don't know how'd I'd search for an answer to a question like this one.

maxcooper

search for "understeer"

Just kidding -- some folks like 'em wider in back. I think SleepR1 could shed some more light on the subject.

-Max

POM HB

Bump

SleepR1

Yes this has been discussed ad nauseum.

Basically same size tires all around preserve the neutral handling balance of the FD3S Rx7.

Larger/wider tires in back relative to fronts dial in understeer (car's nose will tend to push off of the track at the tire's limit of adhesion through a turn). While this is a "safe" setup, it's not the best way to set up an FD3S for good rotation into the turn with the gas pedal (throttle-on steering). Understeer is safe because all you need to do to get the nose pointing in the intended direction through the turn is to lift off of the gas. No need to steer in the opposite direction like you would need to with oversteer (rear end comes out).

There are quite a few FD owners who like understeer, and you'll see them with larger/wider wheels/tires in back. These folks don't like the unsettled feeling of having the rear end let go. They want that back end planted.

Sometimes, you're limited by front wheel well clearance. This is usually the biggest reason FDs have narrower fronts than rears.

Others just like the look of wider wheels/tires in back, and handling balance has little to do with the decision. For these people, it's all about the show.

FWIW, you can run 9.5 wides with 255/40-17s up front, and thus all around assuming you use the proper offset wheel.

I use 9 x 17 SSR Integral A2, 45 offset, 255/40-17 all around. See my sig pic below @ Putnam Park Turn 4.

POM HB

SleepR1,

How about the over all height of the tires? I think if the front tires are shorter, they rotate faster or more and will create understeer.

Being high power, FDs should have taller rear tires...so when acc. in conners, the rear won't come-out easily...unless you wanna drift.

POM HB

PS. SleepR1, please correct me if I'm wrong as I can decide what I wanna do next.

SleepR1

Tire sidewalls act as springs. The shorter the sidewall, the stiffer the spring. In suspension tuning rule of thumb, "stiffest end slides first". If your front tires are shorter in overall diamter (assuming same sized wheel diameter), then your front tires have shorter sidewalls and stiffer springs rates. Couple that with narrower front tire widths, and you have a car that will push like a pig

riddlemr2

I tried searching, but didn't have any luck. I'm looking into buying a used set of stock rx7 wheels for my mr2, which has larger rear tires than front stock. I'd like to preserve that setting by putting a larger-than-stock tire on the rear rx7 wheels. Any advice as for what sizes fit?

POM HB

SleepR1,

I have 235/40 and 265/35. Yeah, I feel the car is understeer a lot when I turn slightly hard with my right foot off the gas. But, when I push the gas hard, the rear comes out. My car is not that powerful....only PFC as a big mod.

Can you help me figure what is wrong? I have my coilover set softer at the front than rear, too.

POM HB

SleepR1

Your problem might have nothing to do with the wheels/tires, and everything to do with worn out rear suspension bushings. Sounds like the symptoms anyway? How old is the car? How many miles on the suspension components?

SleepR1

We have no idea what tire sizes are on an MR2? My guess is the rear stock (newer style) MR2 is 225/50-16 in back, and 215/50-15s front? If that's the case then stock FD Rx7 wheel/tire setup in back should be fine, except you'll need a shorter overall diameter tire up front, like 225/45-16. This will give you a close overall tire diameter match with the stock MR2 setup, but the widths will be nearly the same between fr/rr. You'll have slightly more neutral handling than stock (dialing out some push with same width fr/rr).