[dcoff2]

I bought my car ('07 Z4M) a year ago and finally deleted the valve about 6 weeks ago. Like alot of others, I didn't found the difference to be night-and-day.

When I got the car, it did take a few months to really get used to the CDV "helping" with clutch releases and learning to work with it; I found that the timing becomes more instinctive and the interference becomes less noticeable with practice, though it always seems to require more attention (sometimes annoyingly so) to let out the clutch with a CDV than without it.

Taking it out seems to broaden the ranges of revs and corresponding release speeds that you can use and still get a smooth take-off (takes practice again, like the CDV version...no free lunch..) As I'm sure you've figured out, these cars have enough power that they aren't as easy to modulate as lesser beasts whether the valve is in or out (particularly in Sport mode), and taking out the valve doesn't smooth that out as much as I had hoped.

That said, I'm leaving mine out, and I agree that it's easy enough to do that it's worth a test. If you don't mess up the valve i.e. don't punch out the center, etc.), you can put it back in if you don't like it. There are lots of directions posted, some pretty elaborate with decoy valves (for warranty detection purposes), braided lines, etc., but I think that's making it alot harder than it has to be. I just clamped the line, unscrewed the valve, hooked the line up directly in its place (no adapter, other lines, etc.), bled the slave cylinder a little just in case, and DONE.