Ground Control on my e30

[DSP74]

With a custom built arm that looks alot like this one....

http://img143.imageshack.us/my.php?image=wattsarmstp4.jpg

Note the spacer between the strut and control arm....Car is an E36. Same pricipal.

[DSP74]

Ok I have the answer that was something simply overlooked about the differences between the two cars.......M and non M......

But I'll still wait for YOU to tell me why.

[Elephant]

With a custom built arm that looks alot like this one....

http://img143.imageshack.us/my.php?image=wattsarmstp4.jpg

Note the spacer between the strut and control arm....Car is an E36. Same pricipal.

This set up already exists for E30 M3 but it is not cheap. If you're interested let me know and I can help you out. As a kit it replaces all the stock control arm and tie rod parts with links. All bushings/balljoints are replaced by spherical bearings.

I will be installing this kit on my car next season, it's the way to go for a dedicated race car where proper set up is that important.

Cheers.

[xLibelle]

You explain it to me then. Like I said other than a longer link, making the swaybar more sensitive to adjustment I can't see any.

Assuming non adj bar, and the same link i.e. heim/heim, there really isn't any difference.

has nothing to do with the link. that length is not a factor because it actually doesnt make that big a difference to even mention it as an upgrade.
the point is you tie the end of the sway bar to a place further out to the end of the suspension. stock e30 location is a little further than a half way to the center point of the tire's contact patch. the m3 link mount location is on the strut tube which points down to the inside of the contact patch. This difference in distance is an extreme translation in sway responce.
If you still dont get it, because you cant see the geometry at work here, the simplest example is a lever system like a door. push on the door at the middle and it takes more force to open it than it would if you were pushing at the door knob.

[xLibelle]

With a custom built arm that looks alot like this one....

http://img143.imageshack.us/my.php?image=wattsarmstp4.jpg

Note the spacer between the strut and control arm....Car is an E36. Same pricipal.

nice idea and it could work, but not in your SM class. if you see the angle in which that extension comes down from the strut knuckle, you see its angled outward which i think the e30's is too slightly.
again, simple geometry here, you extend that point down, then to attach it to stock control arm, which is required in SM, then this will bring the hub location closer to the center of the car. AND will reduce camber.
this is why that car has a custom control arm, to extend the length of the arm outward to compensate for the extended mount point.

the e30 m3 design is completely different and can benefit from a simple spacer.

[DSP74]

I'm not required to use stock control arms in SM....Only thing not legal in that picture is the inner mounting point where the innerballjoint mounts. And there are solutions for that using the stock mounting point, which is required.

Anyhow by looking at the picture you can see that stud is actually strait, not angled out, when referenced to the knuckle. Only looks angled out compared to the control arm. And that is because the control arm is in a droop position.

[DSP74]

has nothing to do with the link. that length is not a factor because it actually doesnt make that big a difference to even mention it as an upgrade.
the point is you tie the end of the sway bar to a place further out to the end of the suspension. stock e30 location is a little further than a half way to the center point of the tire's contact patch. the m3 link mount location is on the strut tube which points down to the inside of the contact patch. This difference in distance is an extreme translation in sway responce.
If you still dont get it, because you cant see the geometry at work here, the simplest example is a lever system like a door. push on the door at the middle and it takes more force to open it than it would if you were pushing at the door knob.

A longer link is definately worth mentioning, at least when compared to the really short standard E30 mount. And will definately make larger adjustments. With that said, Yeah I get you. I'd never really looked at the M3 bar on a car, only knew that they were mounted to the strut housing.........So a 25mm bar in M3 configuration is actually giving more roll rate than the same size bar on a standard E30.:up: