Body Brace and Butt Struts!

[Cooper]

Well Gaz just posted a new article https://zroadster.org/articles/basic-bmw-z3-suspension-modifications-by-mike-fishwick.41/ and damn, now I am convinced I really NEED [I told the wife I need it but really want it lol] a body and butt brake combo! Now to start saving....

Anyway, I cannot see any comments regarding any protection or prevention of the dreaded boot spot weld issue on the larger engine Zeds. I assume that any improvement in rigidity would assist in preventing this issue, right?

Cheers.

 

[GazHyde]

Haha, the article was always there I had to fix an issue with the images... but yes,. you probably want them now!

I wouldn't worry about the boot welds on yours as it's a later model, only affected the early ones (and those which had the clutch dumped regularly).

 

[NZ00Z3]

Collective wisdom from another Z3 forum is to fit poly sub-frame bushings and leave the diff bushing as OE rubber. This stops the sub-frame twist on dumping the clutch, which is perceived as the cause of the forces that tear the cross member, boot welds and diff mount.
If your 3.0 L Z3 is a manual, then I recommend you follow this collective wisdom. If its an auto, then its still a good idea. Remember that your 3.0L Z3 has more torque (300 Nm) than the common USA S52 powered Z3M (285 Nm). It's torque that breaks things and the USA Z3M's break the boot welds etc.

I tried the butt strap for about 6 months, its now sitting in the shed gathering dust. It did not give any real benefit and it was awfully close to the petrol tank (~ 10 mm in front of the tank) as well as hanging down and reducing ground clearance to ~ 115 mm. One good wack on a speed bump or gutter and the tank would get a wack too. During an inspection, found one good nick in the brace from contact with something, so off it came.