Z3elda retires from autocross..

[z3elda]

The car is retiring, not the driver.

One of the BMW Z3's weak points is that the rear sub-frame and differential mountings were engineered for 4 cylinder power, but not really for the torque of the 6 Cylinders that came later. The single tab differential mount is subject to cracking, and the trunk floor welds are known to break. I've known this all along, and regularly inspect these areas. While changing my Diff oil last weekend, my inspection revealed a hairline crack developing on the Diff mounting bracket. So, I've decided to stop autocrossing the car until I can get it repaired.

There isn't really an easy shortcut repair. There is a proven repair, but it involves extensive surgery to reinforce the trunk floor and add a dual ear differential mount. Owners that undertake this repair usually make a series of related upgrades at the same time, making the cost quite substantial. Unfortunately, I am not in the position to fund that repair now. I want to continue enjoying the car on Z club drives, so I will keep an eye on the crack and take it easy for a while. It will be repaired, just not right away.

How will I compete in 2014? Not sure yet. As I've said in other posts, I wanted to focus on the fun this year. So maybe I'll do some novice instruction and perhaps a co-drive or two.

[CoolGuy094]

Sad to hear; she will be greatly missed this year. I think your car quickly became a poster-child for the sport in our region, what with the roof tire rack and all stickered up. Events just won't be the same without it.

If you find yourself without a co-drive, just let me know.

[tedebayer]

Sad to hear but understand. I quit autocrossing the M Roadster for same reason.

But every now and then, I think... hmmm roll bar...... reinforcing diff mounts and body to chassis. H I L L C L I M B .... LOL

[matthugie]

That is sad, but I'm glad to hear you'll still be out there. My subframe is out of the car right now, it's a good reminder to check it.

Ted, that's a beautiful car, what have you done to it? S52 powered I assume?

[tedebayer]

That's not mine... just a pic of one with a roll bar I found. Mine is 2000, imola red 2 tone leather. I worked as Materials Manager for interior supplier to BMW for life of Z3 project. Lived at BMW... LOL Had a company car Z3 but wanted an M Roadster so bad. Got one... not planning to let go of it. Here's my baby...

[z3elda]

Once the repair happens, she will be back, at least occasionally.

Her SCCA farewell fling will hopefully be at the National Convention. Tire Rack and all!

[drum3]

You know this is the Hub of the motorsports fabrication world and I'm betting we could find a few skillful professional fabricators that would donate much of their time to do your repair for much less than you think.

[philip1]

Eric I have a high powered RWD that could be co-driven providing I get it done.

[z3elda]

I will definitely take you up on that Phil. and you also Andy!

For anyone that is interested, here is a video put together by Randy Forbes (Not the Congressman) that shows a VERY SEVERE and really advanced failure on an M-Roadster. Mine is configured a bit differently, and not even close to this severe.

Randy is the recognized expert in this repair, and has completed literally hundreds with no repeat failures, even in extreme HP applications.

and here is a thread on Bimmerforums with more detail: forums.bimmerforums.com/forum/showthread.php?1979601