Staggered wheel/tire setups on AWD... why it usually doesnt work, and when it does

[TROLL]

note: moved these posts to make a new thread so we werent getting off topic in the other one...

just a little tidbit of info about different staggered setups.... STi and Evos often run wider wheels and tires up front... i can only guess that it aids in cornering and thats where they need the grip the most.

but yeah, i think those wheels look silly on your car, i liked what you had before better.

[whitezenki]

just a little tidbit of info about different staggered setups.... STi and Evos often run wider wheels and tires up front... i can only guess that it aids in cornering and thats where they need the grip the most.

but yeah, i think those wheels look silly on your car, i liked what you had before better.

I thought you couldnt run a stagger, or even unever wear on AWD vehicles?

[TROLL]

i dont know exactly what they do but i'm almost positive they run wider wheels/tires up front... these are seriously prepped track cars so i'd assume the diffs would be working hard either way, and they probably keep the rolling diameter within a few percent. not exactly sure though...

[joe tom]

i dont know exactly what they do but i'm almost positive they run wider wheels/tires up front... these are seriously prepped track cars so i'd assume the diffs would be working hard either way, and they probably keep the rolling diameter within a few percent. not exactly sure though...

i've heard of this too, but for track only cars, as a DD, the diff would be overworked.

[TROLL]

a little off topic, but informative nonetheless, and informative is good. here are a few replies from a thread on the topic on nasioc...

Unless the tires are very close to the same height front-to-back (I think Subaru says within 0.25" :confused: ), I would guess this would be ill-advised for a street WRX. You don't want to have a significant difference in speed between the front wheels and rear wheels as you'll cook your center differential.

Neil.

Eh it has nothing to do with any kind of gears it has to do with overheating the viscous lsd unit in the center differential. Anyways, there are guys that run wider wheels/tire in the front than on the rear because you have more weight up front and of course urning the wheels is decreasing the grip you have as well. There are some autocross EVOs that run 275/285 tires in the front and 245s in the rear. Larry Fine autocrosses an STI and runs 275 tires in the front and 245 in the rear as well. As long as the diameter of the tire is close, you are going to be fine.

A WRX has a 50/50 split, it's not biased to one side or the other unless there is wheelspin.

STI is rear-biased 65R/35F or somewhere around there, but the reason they run wider in the front is front end grip, which may cause more oversteer and may cause more understeer depending on how the car is setup.


When running wider front wheels, you are suppost to use the exact same sized tires front and rear. The idea behind running a slightly wider rim width in the front, but the same tires all around is that the sidewall will be stiffer on the front tires. The stiffer rounder front sidewall will help with turn in while the rear will give a little more easily to help balance the car during cornering. Japanese tuners have been using this trick on Evo's and STi's for years. The Cusco STi is a rolling catalog so the wheel thing is just an extra little touch. I also don't think that a two pound difference per wheel in the front is gonna wreak much havoc on the Cusco diffs. Stock diffs might be a different story.

edit-wow I didn't realize this tread was from over a year ago...

using this wonderful tool http://www.miata.net/garage/tirecalc.html i just found out that
a 265/35/17 only has a .4% larger rolling diameter than a 235/40/17.
a 275/35/17 only has a .6% larger rolling diameter than a 245/40/17.
those are good to go... especially for a track car.

[whitezenki]

Now I'm interested to see why they would do that, I'm sure their diffs take a hell of a beating b/c any kind of noticeable stagger is gonna be out of the 1-2% change in rolling diameter recommended to avoid. If were talking serious serious race applications then they probably rebuild the diff, or have some baller diff setup that costs like 8K lol. The only other reason's wider front wheels would be of any use is to increase braking power and oversteer, even the best Evo's want to be RWD!

How much you sellin them for?

[TROLL]

made a new thread out of this so it can grow without getting OT.

as you see in the numbers i sampled, they are under 1% different, which i'm sure is within reasonable means. tire pressure and wear can probably have an effect of over 1% rolling diameter alone.
and i agree, for an autox or road course car, they arent putting enough miles on them to wreck the diffs, and if they do, then they'll replace/rebuild. also, on a car thats pushing the corners that hard, the diffs are going to spend more time working to get traction than to overcome a small rolling diameter difference.
and the reason to go wider up front is becuase on a AWD car you are asking 2 duties of the front wheels... turn and accellerate at the same time... so traction is much more often an issue up front than in the rear so the extra rubber helps.

[evomike]

people do it alot, wider tires in the front to eliminate understeer and such

[markley02]

What about cheaper tires in the rear and better tires in the front. That is what I have on my evo. Although the max handling will be less than wider fronts, the handling characteristics is what I am after

[joe tom]

What about cheaper tires in the rear and better tires in the front. That is what I have on my evo. Although the max handling will be less than wider fronts, the handling characteristics is what I am after

are the 4 tires the same speed/load rating?? just a cheaper rear set?? if you have different ratings, won't the handling be negatively effected?

[markley02]

speed rating is the same. Softer in the front (advan's), harder compound in the rear. I have been like this for 8K miles and have had no ill effects. Just oversteer, the way I like it.

I have also done the same with my M3 in the past. I hate understeer with a passion.