Here we go again....

[Axxe]

Also, Mtech2 wheel FTW, don't have pics installed but yeah, it's perfect, wouldn't want to go any smaller.

[1BADBMR]

Nice build Axxe, can't wait to see the finished product.

[T.Dot_E30]

What offset, and width 18s are you going to run?

[doogee]

Originally Posted by T.Dot_E30

235/40s all around, on 17x8s squared setup. No Strut bar. It could be how the coilovers are setup or the alignment, e36m3s are known to understeer, bf.c guys seem to suggest more camber up front.

Front swaybar will fix the understeer

Do not get a rear bar though lol.

[BigD]

Originally Posted by doogee

Front swaybar will fix the understeer

Do not get a rear bar though lol.

More front bar = more understeer.

[T.Dot_E30]

So front sway bar or front camber plates?

Which one should I get?

[doogee]

Originally Posted by BigD

More front bar = more understeer.

Not on an e36 or e46. Trust me.

Ask any club racer or Arek. And from my own experience, a huge front swaybar gets rid of the stock understeer.

[BigD]

Originally Posted by doogee

Not on an e36 or e46. Trust me.

Ask any club racer or Arek. And from my own experience, a huge front swaybar gets rid of the stock understeer.

I'm not a religious man, I don't take things on faith. Without an explanation, I'll stick to my opinion. Not saying you're wrong but the physics of weight transfer apply to anything from a bus to a formula car. If it's true then there's probably a design flaw that I'd like to hear about and why it wouldn't be better overcome with other ways (eg static geometry changes and spring rates).

[doogee]

Originally Posted by BigD

I'm not a religious man, I don't take things on faith. Without an explanation, I'll stick to my opinion. Not saying you're wrong but the physics of weight transfer apply to anything from a bus to a formula car. If it's true then there's probably a design flaw that I'd like to hear about and why it wouldn't be better overcome with other ways (eg static geometry changes and spring rates).

Scotch (Arek) explained it best to me once.

"The BMW mac strut works best when the roll rool is reduced. This can be done with stiff springs, but then you compromize other handling, so a stiff front bar does this well. you're correct the soft rear bar is for putting down power. If you're lacking rotation, it's far better to add more spring (or tune the shocks) than stiffening the bar ... it will work, but usually at the expense of corner exit grip.

What feels good on the steet really has no bearing at all on track handling ... you're never anywhere close to 100% on the street to be able to tune it right, so just go with what works best for you (comfort/etc), and worry about atcualy handling tuning at the track."

[T.Dot_E30]

Sorry, don't wanna cluter Tomek's thread any more than we already have.
Can we continue this here?
http://www.maxbimmer.com/forums/show...26#post1485226

[BigD]

I don't really see an explanation though, other than:

"The BMW mac strut works best when the roll rool is reduced."

Why?

[Steve30]

isn't that the case for all struts since they roll and reduce negative camber vs. a wishbone suspension which actually retains negative camber?

[BigD]

Originally Posted by Steve30

isn't that the case for all struts since they roll and reduce negative camber vs. a wishbone suspension which actually retains negative camber?

Yeah, which is why you run exaggerated negative static camber, so as the car rolls (and with macpherson strut, also gaining +ve camber under compression), you actually get a better contact patch.

[Steve30]

ok, so then running a bigger front bar will result in more weight transfer to the opposite wheel resulting in a greater contact patch for both sides right?

[BigD]

Originally Posted by Steve30

ok, so then running a bigger front bar will result in more weight transfer to the opposite wheel resulting in a greater contact patch for both sides right?

A bigger sway bar will transfer force to the opposite side, and through the other side's spring and its own torsional stiffness, effectively add to the spring rate of the outside wheel. The problem is that when a car rolls to one side, the "weight transfer", or basically just the car leaning on that side, causes more pressure on the wheel, increasing friction. Imagine an arrow pointing out the side of the car - that's the centrifugal force (car wanting to go sideways instead of turning). If the car rolls, imagine that arrow no longer pointing sideways but a little down. The vertical component from this force will push down on the wheels (until you roll over of course lol). So the flatter the car stays, the lower this force will be.

The other part is static vs dynamic friction. Static friction is much greater than dynamic. Ever notice how if you push a chair, it takes a lot more force to get it moving than to keep it moving? That's it. Same thing happens with tires - if you start sliding, you have way less grip than if you were rolling. You don't want to overcome the static friction barrier. But when you initially turn in to a corner, the outside front tire has to generate enough force to begin the initial change in direction (which will later be handled by both front and rear). So the more time it has to do this work, the less instantaneous force it has to generate. This is why if you turn in too suddenly, you'll understeer - asking one tire to generate all that force right away. The same thing happens with too much roll stiffness. If the car has some body roll, while it rolls over ("weight transfer"s), the tires do less work because part of the weight of the car is not being supported. But a stiffer roll resistance will have a similar effect as turning in sharper on a softer car.

So as you can see, this will be true for anything with 4 tires and pivoting suspension. There can be other complications but in the ideal world, they are solved with static geometry changes.

That being said, I'm no expert, just read a bunch of books n shit.