Re: Don't forget about the lower bushings & jo (archive)

Using 16x7.5 20mm offset rims with 225/50-16 Yoko AVS Sport tires. I notice these tires come extremely close to the strut housing's conical spring perch base and I wonder whether there is in fact room to increase negative camber, even if I tried slotting the bushing hole. I guess a 5mm spacer might help. When you say hard cornering takes its toll on the balljoint and they might need replacing, is that because they may fatigue and suddenly fail or because they get sloppy and result in less negative camber during cornering? I.e. is it a safety or a performance issue? Could you suggest an upgrade for the ball joint from a bigger Bimmer or aftermarket supplier, if such exists?
I already have the strut brace.

James, how do you find the M3 compares to your E28 in terms of tire scrub? A part of my mind says quit trying to make something out of the E28 that its not intended for and, if I'm going to prep for SoloI, start over with a better base in an E30 M3. You've posted usefully several times in the past on the relative merits of the two cars... I love the 535is but I feel I'm at the crossroads.

Don't forget that the lower control arm takes most of the lateral load (hence the term lateral link) from cornering. That bushing may be solid rubber, but it's still rubber. Plus, the balljoint is not a solid spherical joint like you'd see on a racecar. These two combine to reduce negative camber under cornering loads. These cars are heavy! A couple of driver school seasons really take their toll on the balljoints, so count on replacing them every two years if you do a few events a year.

You could slot the lower control arm bushing hole to increase negative camber, but then you'd need to adjust the tie-rods and upper control arms accordingly. Reinforce the metal around the holes if you decide to slot them. Some racing classes do allow this, so it's not an unheard-of procedure.

Chris is also correct when he recommends the upper strut brace. It prevents the cornering loads at the tire from pulling the upper shock mounts apart. You may not think that it's a lot of force, but think how much force it takes to accelerate the front half of your car at 0.9 g's. No, you do not need a solid-end bar, pivots are perfectly OK. There is no way in hell a 3' long bar is going to prevent upward movement of the other shock tower.

What size wheels and tires are you using?

James M
james_535@yahoo.com
1988 M3
1988 M5
1983 535i

Follow Ups:

Re: Don't forget about the lower bushings & jo Chris Graff 19:10 10/16/2000 (1)
- Right Chris, but don't forget... JamesM 07:58 10/18/2000 (0)

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