Ideal ride height?

[Brew]

Wondering if anyone has done any testing as to how low you can go on the e30 front and rear suspension without adversely affecting suspension geometry. And also if there are any off-the-shelf options for adjusting bump steer.

It seems the best way to measure would be fender lip to center of wheel, since some of us are running under or oversized tires.

[rsafier]

I always measured from the trim edge as its level across the car. Some of us are crazy and completely chop fenders out

[Jean]

I wonder just how much can be done with just pulling the fenders out? I gotta try it.

[Brew]

I always measured from the trim edge as its level across the car. Some of us are crazy and completely chop fenders out

Thats fine for your own measurements with similar height tires, but if we're talking about suspension geometry, measuring to the wheel center will allow you to compare suspension settings regardless of overall tire diameter.

[rsafier]

True, but I was more pointing out ones fenders are not necessarily a static feature on the car. I suppose inner fender well might be...

[mazur]

I have set the front height so that the LCA's are parallel to the ground and set the rear so that I have a reasonable amount of camber.

Does ride height in the rear ever have a major affect on suspension geometry? And if so, in what way?

[Brew]

True, but I was more pointing out ones fenders are not necessarily a static feature on the car. I suppose inner fender well might be...

Ok, I see what you're saying now. I do think for most of us the fender lip is the way to go.

I have set the front height so that the LCA's are parallel to the ground and set the rear so that I have a reasonable amount of camber.

Does ride height in the rear ever have a major affect on suspension geometry? And if so, in what way?

Disregarding alignment settings, the rear suspension is really limited only by suspension travel, as the camber change during suspension movement is linear and the toe change is fairly minimal. At least thats what I got out of the article on www.e30m3performance.com

The front is a lot more complicated, and thats mostly what I'm curious about.

[RedStar240]

h&r sports have a nice drop but for a track car you might want something stiff like H&R racing or Eibach Ground Control.

[Jean]

h&r sports have a nice drop but for a track car you might want something stiff like H&R racing or Eibach Ground Control.

who said anything abour H&R sports drop

[808BMW]

I've always heard that once your control arms go past parallel (to the ground, at static ride height) your just doing more harm than good.
Which isn't very low, my car would need to probably come up a full inch or maybe more.

[SA E30]

I have set the front height so that the LCA's are parallel to the ground and set the rear so that I have a reasonable amount of camber.

Does ride height in the rear ever have a major affect on suspension geometry? And if so, in what way?

My understanding is that setting your control arms to parallel while the car is static will lead to a positive camber curve, when applicable side of the car is under compression, as it would go past parallel ?

[AlarmedBread]

It's not really possible to make that generalization, ideal ride height at one spring rate is different from another.

A brief explanation.

http://e46m3performance.com/tech/transfer/pg-2.htm

[nando]

My understanding is that setting your control arms to parallel while the car is static will lead to a positive camber curve, when applicable side of the car is under compression, as it would go past parallel ?

I don't think that's quite true - the angle between the control arm and the strut would have to be less than 90 degrees before you started hitting the positive camber curve. it's not neccesarily the relationship between the control arm and the ground that matters in that respect.

[joshh]

There are way too many variables to setting the LCA at static for "the best performance". Accelerating, braking, what springs and shocks you are using, turning, off camber turn the surface and more make it next to impossible to have a perfect angle for the best performance.
The main thing is to go as low as you can without sacrificing suspension travel. That usually is the best setting because with most cars you can only lower the car so far anyways.
Even on my Integra (double wishbone) I can only lower the car about 2" before I start riding the bumpstops and I'm on 450lbs springs up front. The lower LCA at that point is sitting almost perfectly at 90*.

[rsafier]

Excellent points.