Stiffening the convertible chassis

[BDK]

what I will do when I install my new subframe bushings is the same as I did with my E28's...
Stock HD Mounts filled with poly, you get the extra stiffness of the poly filling without the extra roadnoise that pure solid mounts transfer....

but with a cab, you're picking up road noise anyway, but the hardtop does make a world of difference with that too....
I'm doing big sway bars, lowering springs, good shocks (billie or koni), the Xbrace, prolly throw the buttstrut in there too boot...
I thought that I read somewhere that you should not run a front strut tower brace inconjunction with an Xbrace, anyone else read/hear that?

[Lance Racing]

Nice job.

For those wondering why BMW didn't do this from the beginning, remember their customers back in the day. For $35k you could buy an E30 M3, for a just a few thousand less you could buy an E30 cabrio. So in those relative close price ranges, the people looking for performance were buying the M3. The original purchasers of cabrios were boulevard cruisers and were not putting the demands on the car that enthusiasts are now.

Did I see this cabrio at the Picnic last year? If so, it was stunning. White on white?

[xLibelle]

I imagine that if you have the OEM rubber subframe mounts, where the sides do not have rubber, then the frame is likely to resonate to some extent... rather as much room that the mount cylinders will allow. Much less likely if you have something solid in there like urethane mounts.

Taking a close look at that region of the car, you have a considerable amount of structure and framework. Near-by lateral motion is controlled by the base of the back seat, for the most part. As the car gets into a turn, the lateral forces will roll the cabin's walls and relocate the subframe mount points in some way, shape, or form. To say exactly how much is probably a hard thing to do. Is it enough to effect the suspensions geometry for a street vehicle with some HPDE's? NO WAY.

But then this shouldnt be a thread solely about if the butt-strut works or not and I will stop the tread shitting here. I doubt you're hurting anything and more than likely have provided for some much needed frame strengthening. Is it worth the ground clearance loss? i dunno.

Good luck with it.

[CorvallisBMW]

OK, well that sums it up about the buttstrut. rubbish

I'm not so sure. I noticed a difference, without a doubt. Was it as much of a difference as the mason x-brace? No, but it was a difference. I still think they are worth doing, and the testimonies on the butt-strut website from Z3 and E30 owners count for something too.

[N2MYE30]

Ive got to remember this when I upgrade the suspension.

[Liam]

OK, well that sums it up about the buttstrut. rubbish

Pretty much.

There is some stuff back there that could use some extra control, but like I said in an earlier post, it's an engineering nightmare and where it would have to go to make it work would mean tearing the whole world apart.

[xLibelle]

OK, well that sums it up about the buttstrut. rubbish

[ejnight]

If you come up with something, let me know. Your fab skills far exceed my own :)

For sure.

[CorvallisBMW]

I made my own X brace for my new Vert. It was a night and day difference for sure. I will have to look into the rear.

If you come up with something, let me know. Your fab skills far exceed my own :)

[ejnight]

I made my own X brace for my new Vert. It was a night and day difference for sure. I will have to look into the rear.

[twright]

I made my own "butt-strut" for my 1989 325ic. I left it on there for a year, and I couldn't tell much difference during the street driving that I do. I took it off and it seems the same.

[CorvallisBMW]

75% eh? So like almost all the shake and flex, but not all of it. More than half, just not all. somewhere in between that. like 3/4 of it. ;p


I'm still a pretty big disbeliever with the buttstrut thing. If Z drivers have reported on the success of this kind of thing, can someone show the posts/threads/site on it? I recall the last thread here about this and it was all hear-say.

I don't know many Z owners, most of what I saw was the user testimonials on the strong-strut website.

any pics of it installed?

ya, on the first page.

where can I buy a "butt strut"?

http://www.strong-strut.com/Butt-Strut.htm

[bmw325csi]

where can I buy a "butt strut"?

[oekundar]

Interesting...I was just wrestling with the cabrio tonight...something to look into.

[Liam]

75% eh? So like almost all the shake and flex, but not all of it. More than half, just not all. somewhere in between that. like 3/4 of it. ;p


I'm still a pretty big disbeliever with the buttstrut thing. If Z drivers have reported on the success of this kind of thing, can someone show the posts/threads/site on it? I recall the last thread here about this and it was all hear-say.

I've twisted, shook and bent a lot of BMWs.

The Butt strut, I just won't say anything there.