Stiffening the convertible chassis

[CorvallisBMW]

impressed--

I thinks I am going to invest in the X-brace.

I think my rear is solid with the poly sub-frame bushings.

I think you're right. The poly bushings will do a lot more to stop flex than the stock rubber ones. if you suspension is sorted out enough to be runnin gpoly bushings, the x-brace will make a huge difference for you.

corvallis bmw
I am in admiration at the bar you fabricated for rear lower beam double shear
I admire the fact that some people do not whine or pretend that a structural problem does not exist , and have the intelligence to make something from nothing
looks great good work JOHN MASON

Thank you John. It's not quite as nice as your piece, but for a 1st attempt I'm pretty happy.

Darin you are my hero:up:

:up:

Wow, if you catch that rear bar on anything you'll tear your rear subframe to shreds. Aside from that potential danger, looks good.

Hopefully that wont happen, lol. I'm already extremely careful with this car.

Like I've said, I don't know why BMW let the e30s out of the factory without it.

You don't notice the chassis flex nearly as much on a car with stock suspension and wheels. Everything is so soft, not much force ends up making in the the chassis, the suspension absorbs most of it.

[Cha Ching]

Great knowledge, thanks for sharing. Just what I was looking for to stiffen my 21-yo vert's squeeks, rattle & rolls! I will be looking to pick up a crossbrace soon. Any plans to market your home-made brace?

[cactusjacks1]

I played around with it a bit more, running just the x-brace, and then just the rear. The x-brace certainly makes the biggest difference. It's just built more stout and because of it's strait-tube design, resists the transmission of forces better. The bends in my bar means it's not quite as stiff, but like I said, it's a prototype. Ideally I would like to re-make the bar with a series of long, large-radius bends instead of shorter, sharper bends (and get rid of the exhaust notch).

I also run the Mason X bar on my cabrio & it made a world of difference in cowl shake. I really like you "butt strut". I am trying to recall if your running a strut tower brace - if so, was it on in both instances of on/off X & rear braces?

[BDK]

can I ask a question?
have you run the butt strut? why not just run one of those? They do fitthe e30's right?
Not that there is anything wrong with yours but did you just fab your own due to your own fab skills?
just asking and not trying to insult, atleast you can weld, I can't/haven't really tried and don't have the tools?

Do you know if the Mason xbrace will work with an M30 transplant?

[CorvallisBMW]

Great knowledge, thanks for sharing. Just what I was looking for to stiffen my 21-yo vert's squeeks, rattle & rolls! I will be looking to pick up a crossbrace soon. Any plans to market your home-made brace?

Not really. It took a lot of time to make this, and seeing as how I'm just finishing college and about to start a new job, I don't have much time to devote to building these.

I also run the Mason X bar on my cabrio & it made a world of difference in cowl shake. I really like you "butt strut". I am trying to recall if your running a strut tower brace - if so, was it on in both instances of on/off X & rear braces?

Yes, I have the IE (Sparco knockoff) strut brace, and it was always on the car.

can I ask a question?
have you run the butt strut? why not just run one of those? They do fitthe e30's right?
Not that there is anything wrong with yours but did you just fab your own due to your own fab skills?
just asking and not trying to insult, atleast you can weld, I can't/haven't really tried and don't have the tools?

Do you know if the Mason xbrace will work with an M30 transplant?

Yes, they do fit the e30s. They make theirs out of 1/2"x2" 6061 bar stock. A flat bar is much weaker in bending and torsion than a hollow tube, plus this weighs less. But I am going to make one out of 6061 bar stock just for fun and see how it compares. Not to mention, I didn't want to pay $375 or whatever they wanted for a glorified piece of aluminum bar.

I have no idea if it will fit on M30 cars, I suggest emailing John Mason and asking him.

[xLibelle]

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.

[shmutzigE30]

any pics of it installed?

[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.

[oekundar]

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

[bmw325csi]

where can I buy a "butt strut"?

[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

[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.

[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.

[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]

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

For sure.