I have always heard that a strut brace is especially beneficial on a convertible where one wouldn't have as much structural rigidity as a coupe. I'd go OEM and get the BMWCCA discount.
The strut brace does add torsional rigidity. Your point about the Z4M chasis needing it is valid. I was told by a guy who installs them at Performance Art in Gilroy that they can actualy screw the ride up under certain less than great road conditions when turning at speed. If you are going for minimum track times you want one. If you like a good performance ride on the road, you probably don't want one. Performance cars all ride relatively stiff. It's the nature of the beast. After awile you kind of like it because your are more connected with the road. In any case, no Z4M will ever make you **** blood like something that's full race. Even with a strut brace. Enjoy!
I've had the OEM brace for several weeks now, it has noticeably improved my handling and cornering. I don't track the car but it is much more responsive. I haven't noticed any negative effects from the brace. The weight is only a few pounds and as an added benefit makes the engine compartment look nicer.
Car has been pretty good but it's at the dealer now getting a new VANOS. The up side is that it'll get fixed and they gave me a 335i for a loaner. Now how to switch my seats for the sport seats in the 335 before I return it?
I was asking about your engine due to the hydraulic lifters' propensity for making noise and related posts. How many miles do you have on it? Glad the dealer is supportive w/ the VANOS. I really like the fog lights of the facelift.
Sorry, it has been into the dealer twice for the lifter noise. They could not duplicate but I did have two movies on my phone that showed the noise. They are supposed to be getting a retro kit that is different from the head replacement and previous "fix" that the will install when they have a couple under their belt. They don't want me to be the first and want to make sure that it works before they try mine. I have 33K on the clock.
by the way I just noticed the full fledged bedazzled roundel logo under your hood vs. the M, molded in plastic black.
Yes, it just added a little zip under the hood. A couple of bucks at the dealer and some 3M double stick tape.
Or a CAI. The part I don't understand, if one shock tower is being stressed, doesn't the load get partly shifted to the other? Is that a good thing? As far as I am concerned unless the strut bar is connected to the firewall, it's just bling. Not that there is anything wrong with that.
Keep in mind the cross tower brace was standard equipment on the E46 M3. It does maintain the chassis integrity and spread the stress load
If they are cornering forces its a good thing . If it's side-impact collision forces, it's a bad thing. A strut tower brace helps the outside strut tower from deflecting under the high stresses of at-limit cornering. The inside strut tower doesn't have much stress on it through a corner, so by connecting the two towers together with a strut brace, both take some of the load and the outside one is not over-stressed (...which might cause metal fatigue over time). I doubt the strut towers need to be braced to reduce movement during cornering: Z4 have pretty stiff everything. In a collision, its bad to have a strut brace since if one side gets bent, both sides get bent.
The Dinans have creases/fold points. Hopefully "give" enough to not jack up the other side if you do get hit on one side.