Cal Club Autocross Forums

With same size wheels and tires would a wider track in the front or back give better rotation? On a fwd.

Multiple factors, but the simple math is wider track = longer lever on the suspension geometry = softer "spring rate" = more grip.

So if you want it to rotate more, and the only adjustment you have is to widen one end, widen the front.

Robert Puertas wrote:Multiple factors, but the simple math is wider track = longer lever on the suspension geometry = softer "spring rate" = more grip.

Does the wider track = softer "spring rate" principle hold for both double wishbones and macstruts?

Kai Hur wrote:With same size wheels and tires would a wider track in the front or back give better rotation? On a fwd.

Back when I was running the Integra in GS, I ran Kuhmo Victoracers in the front, and Falken Azenis - 215's (model not size) in the rear.
Similar intent, where your looking at track, I played with rubber compounds to increase grip in the front, decrease in the rear, for more rotation, since I couldn't play with spring rates in Stock.

I did the same with my accord a decade ago.. 225 Hoosiers in front 205 v700 in the back..

Kai Hur wrote:I did the same with my accord a decade ago.. 225 Hoosiers in front 205 v700 in the back..

Trouble with mixing tires is they typically change differently with heat. This specific case I can see the hoosiers being super sticky cold, then fade as the V700s get good, i.e. your rotation characteristics change quite a bit as you drive.

Air pressure and staggered widths seem like a more consistent solution.

Jay W

Well my initial post was intended for my spacer placement.. same wheels and tires all around. As Robert recommends seems that placing the spacer in the front widening the track will yield better rotation

I'm a total newbie at this, but wouldn't making a car wider make slaloms and linked turns more difficult? I understand the CG would be lowered; and maybe that offsets the bigger steering inputs required.

Anyways I always feel like my car is too big whether it's autocrossing, driving on the street, or finding a parking spot; maybe I'll get a Smart car :)

Eric Wong wrote:I'm a total newbie at this, but wouldn't making a car wider make slaloms and linked turns more difficult? I understand the CG would be lowered; and maybe that offsets the bigger steering inputs required.

Anyways I always feel like my car is too big whether it's autocrossing, driving on the street, or finding a parking spot; maybe I'll get a Smart car

With spacers, were talking 1/8", 1/4", or 1/2" per side.
- Personally I'm much more than that. OEM rims are 45mm offset, my aftermarket rims are 30mm (15mm difference = .6"). OEM's were 5", aftermarket are 7.5" (another ~1" wider?) I also run two (2) 1/4" spacers on each wheel. So I'm at ~ +1.1 - 2.1" in additional width.

IMHO,I get pretty close to cones...(I know my car's corners pretty well)... but not consistently close enough that even the 1/2" (or in my case even the 1-2") started making me hit cones left and right. If I was always 3-4" off of the important cone's... I'd be ecstatic! At best the change brought me closer to being within that range, at worst (if you could call it that), it's brought me even closer than that range.