Z3M cars are notorious for ripping out the rear subframe attachment for the diff.
They run a 188 stock. There's a guy that actually makes a living fixing them in Florida. I've talk to him about installing his set up on my Ti.
http://www.spcarsplus.com Eventually I am putting a '97-98 Z3 M52 2.8 with cams for around 220-230 Hp. I think the 188 diff will hold up if we change the oil before every race and add a temp gauge to monitor things. Might even add the Rogue Engineering finned diff cover if needed. My Ti isn't going to be sitting on the ground to worry too much about ground clearance.
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