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      08-07-2013, 08:41 PM   #12

Drives: 1995 E36 M3
Join Date: Mar 2007
Location: Norcal

iTrader: (2)

Originally Posted by DVCperformance View Post
Thought I'd revive an old thread rather than start a new one...

jbass524, what's the verdict on the your research for fitting the widest wheel/tire combo on the F30?

I've been trying to decide on a wheel/tire combo, but was leaning toward something for all around use as well as track...and also toward a staggered setup.

Two questions:
Is a staggered setup (say, 8.5"/245mm and 10"/275mm) a compromise on the track? (probably for autoX, but I am mainly interested in track)

Also, would it be worth getting a little more width up front (9" wheel as opposed to an 8.5" wheel) even at the cost of a few pounds of weight penalty per wheel?
Hey DVCperformance,

There's a fitment article here:

A heavily staggered setup like this, 8.5"/245mm and 10"/275mm, is not good for a BMW on the track. You would do much better with 8.5" front and rear. Just because you can fit a wide tire doesn't mean you should.

The reason for the same sizes - square setup - is that BMWs are a little heavier in the front (nothing like an AUDI) so they need every bit as much rubber up there as they have in the back. BTW, a square setup is the best handling mod you can do and should be the first one.

The next handling mod should camber. Here's an excerpt from the above linked article:
Benefits of Negative Camber[/size]
Additional negative camber balances a BMWs handling and significantly increases its performance. Racers typically run an additional -1 degree of camber on the front compared to the rear, sometimes more. From the factory, BMWs typically have +2 degrees more camber in the front compared to the rear. Although this is done to give you early warning in the front tires when you’re going a little too fast in corners it biases grip to the rear tires. By adding negative camber to the front you can more perfectly balance a BMW’s handling by creating similar levels of grip, front and rear.

Wider front tires also contribute to perfectly balanced handling on a BMW. If you want to run aggressively wide tires in the front, negative camber (commonly referred to as “more camber”) is almost always necessary to help clear the front fender by tucking the wheel under it.
JMK007 and I have both taken our F30s to the track and we both drove them hard. He has a review of his and I think I posted my thoughts also. I won't be competing with mine but JMK007 will. He and I have talked on the phone and I can see he knows what he's talking about and I would pay attention to what he has to say.