This is and observance from me that I ask everyone to think about it before responding. (FYI, I wrote this for the Scionlife forum. But I would like to hear more opinions.)

The reason I am posting here is because I have a friend with a WRX that is running Hotchkis Sways. On the lowest setting he now gets oversteer instead of understeer. So wouldn't combining sway bars that induce oversteer with staggered wheels be better? Another thing, hox would wider rears make understeer worse on a car with understeer already? The front wheels begin sliding at the same speed no matter how big the rear wheels become (relative to the turn). I mean, of course you want the front wheels as wide as possible, but rears have more room, typically, for wider wheels. I know some professional AWD cars run larger front wheels for stability, but maybe that is way into the extreme for handling that rquires a LOT of fabrication?

My view: I have read quite a bit about people who get Hotchkis or Progress (maybe even TRD) sways and the understeer becomes oversteer. This is where staggered wheels should be awesome. It is obvious that with more tire in the rear of the car, the harder it would be to slide them and thus, useful! This means that the wider the rear wheels, the faster you can go in a turn before you get oversteer. Maybe it is not even 5 mph faster, but like an S-pipe or CAI, every little bit helps.

This leads me into the next argument that the tC does not have enough power. Aside from the obvious of getting a turbo kit to up the power, there is the fact that in a road course, and even an AutoX, the car is already rolling and does not need to overcome as much of the weight as when the car is at a dead stop. Add to the fact that you can corner faster so you do not have to slow down and accelerate as much in these turns.

Now, this comes from my observations and logic. With that, comes my question. Does having the rear wheels further from the body mess with the turning geometry and hurt handling? I do not know much about suspension geometry but, like the springs argument, its seems like there could be a benefit to go so far and at a certain point the handling reaches maximum effectiveness before deteriorating. Maybe being wider than 2" in the rear (combined) there is a positive or no effect on handling or maybe my car will flip and burst into flame, the radio cover shoots off into my arm and the clutch pedal shoots back then forward throwing my knee into my face.

Common sense is that there are many manufacturers that use staggered wheels (specifically for sports cars). I mean, check out the Z06 Corvette: 18" x 9.5" front and 19" x 12.0" rear ! Let us not forget that the C6 did very well on the road course for Top Gear.

 

staggered wheels were and are used on many cars and no problems what so ever apart from a flat tyre which was over come with the space saver tyre thanks to Renault/Citroen

 

If you do a search here and on other Audi forums, you'll find that this has been discussed many times with one conclusion: if you are performance minded, staggered wheels don't belong on an Audi (unless you're talking about the new R8). Virtually all Audis have a pretty serious forward weight bias. This makes then tend to understeer. Staggered wheels are used to tame oversteer. Putting them on a car that understeers will make them do that more so.

If you're more concerned about looks than performance, than have at it. If you care about performance, don't do it.

 

Some purists adhere to the philosophy that a suspension designed to maximize traction would utilize no or very small sway bars, and that springs (coil, torsion, leaf) of the appropriate rate at each corner should be used in lieu of sway bars to produce the desired handling balance. I know of one well-respected and very successful tuner who forsakes sway bars completely, and believes that an optimized suspension may just well be one that always understeers at the limit,and it is up to the driver to keep the carjust under that limit in order to extract the maximum performance from the car.While this philosophy is a little too fundamental for my tastes, I do agree that sway bars are functionally a compromise and should be leveraged sparingly to fine tune the balance of the car.

That being said, taking a car prone to understeer, adding sway bars sized to the point that the car oversteers, and then using wider rear wheels to tune the handling seems like a backwards approach to me.

The route to maximizing grip is to maximize the size of the contact patch. As the body of the car rolls/sways in a corner, the camber of each tire changes, and how the camber changes should dictate what approach should be taken to manage the sway.Too much roll resistance and the inside tire lifts off the groundwhile contact patch of the outside tire shifts to just the outside shoulder. On the other hand, too little roll resistance can result in the camber at the inside and outside corners getting wonky, or ultimately the chassis reaching the limit of its movement too quicklyand the roll resistance rate reaching inifinity (at which point you start seeing the car getting onto its roof). The optimum is somewhere in between, where the suspension continues to give some as cornering load increases, but resists enough so that as the cornering load increases towards the limit the contact patches progressively shrink so that the car slides as opposed to flipping.

So given all that, putting wider wheels and tires on a car to increase the width of the contact patch will raise grip levels, but I would tend to think that the situation you describe - where the addition ofstiff rearsway bar necessitates the use of wider wheels to keep the car balanced - indicates that the rear bar is too stiff (or the front bar too soft) and a better approach might be to change the rates of the bars (adjustable endlinks?) to tune the balance.

IMHO, FWIW...