Recently, MGarrison mentioned that E30 swaybar mounts eventually break when stiffer aftermarket sway bars are installed. http://stage.bmwcca.org/forum/showthread.php?p=6395#post6395 It's the first I've heard of it. I've recently upgraded to Eibach 20mm front and 16mm rear swaybars on my 1987 325i convertible. I have them both set to the middle stiffness setting. The set-up is quite a bit stiffer than stock. How do you reinforce the mount points? Do I do it preventatively or do I wait until something breaks? (And, I suppose, is MGarrison exaggerating the problem?)
How do you reinforce? The rear ones indeed look particularly vulnerable. They receive a direct shearing force across the bracket. When I installed the Eibachs, I worried about how much direct force the rear brackets would carry. In the front, all the force is transfered directly to the frame. Sorry for the personal comment. I was just looking for reassurance that maybe the problem isn't that serious. I was not making a personal dig.
I mentioned that based on my personal experience after modifying the suspension and running my E30 at something like 60 track events or more since I got my first 325is in '92. After adding larger swaybars, the rear tabs broke after a certain period of time. As I recall (this was back in the mid-90's mind you, it's been awhile) my shop welded a small reinforcement in, triangulating the bracket in some fashion. I think one side or another of one of the mounting tabs partially cracked again, and a beefier reinforcement was added in. Turner Motorsports has a part for dealing w/ the bushing brackets - http://www.turnermotorsport.com/html/detail.asp?PRODUCT_ID=TSU3075308 I believe it bolts through the trunk floor. I don't recall having as many problems with the bushing brackets as the tabs on the trailing arms. I'll try to take some pictures of my back end (ha, ha) sometime. If you're not going to flog your car around a racetrack or an auto-x for many hours every year, then you may find your car isn't subjected to the same degree of stress mine was, and they may hold up just fine if street driving is all you do. Obviously they don't start out broken, so I'd say it can certainly be something to just keep an eye on, or check out whenever you happen to get it up in the air.
