Anyone running a "strong-stut" or "butt-strut"?

[Justin B]

^ dude, you are fucking awesome! I will be working on a jig for manufacturing these this weekend. With some luck, I can start a GB soon for about 1/4 the price of those retail ones.

dooo itt lol

[CorvallisBMW]

so will these be only for verts? Im looking into some bars for my hardtop... if yours will be made with some stronger sources, i am def. intrested. im sure i will have a friend who will buy too...

are you making front or back?

No they will work for all body styles as all rear subframe studs are in the same location. They will be made of 0.5"x2" steel bar stock, so they should be very strong. They will only be for the back, as the front is already tied together by the front subframe (which has no rubber bushings to absorb chassis flex)

At some point we may look in to building an e36 syle 'x-brace' fro the front, but for now it's mostly just a pipe dream. We'll see how well these go.

[devonjordan]

Im in for one...

[ditchdigger]

It seems to me that 1/2" thick is a bit overkill. I was thinking of 3/8" because I have it laying around and then on the strong strut website these pics look to be about 1/4-3/8" thick


Another question. The ovaled holes on the end? is there something special about the rear subframe mounts that require that or are those just there to provide a bit of "adjustment" to fit cars that might be bent?

I suppose I could go lay under my car and measure but its raining and I am feeling lazy;)

[CorvallisBMW]

According to the dimensions provided by td325ic, it is 0.5"x2" bar stock. And yes, I assume the oval holes are to allow for a bit of fitment ease. These chassis flex fairly easily, and a bar that fits snugly when the car is on the ground may not line up quite right while it's in the air on jackstands waiting for install.

EDIT: I just pulled out a peice of of 0.75"x1.75" stock I had lying around, and it's fucking huge and really heavy. I think I may end up bulding this out of 0.25"x1.5", I doubt the press could even handle 0.5" or even 3/8" stock. And 0.25"x1.5" will still be very, very stiff.

[Van Westervelt]

Did you double check the overall length of the bar?

[ditchdigger]

Next question. Anybody know off hand the size and thread pitch of the subframe bolts that these special female bolt fasteners mount to?


I have a plan on how to make it just need to know what tap/drill to use.

[Van Westervelt]

m14x1.5

[td325ic]

Did you double check the overall length of the bar?

I just double checked the length of the bar. I also figured out the unbent length of the bar by laying masking tape on it, marking the ends, then laying the tape flat on the floor and measuring it.

unbent: 51.5"
bent: 50.5"

It is indeed 1/2" thick by 2" wide. The thing weighs around 15lbs.

Also, I wanted to mention, from what I've read one of the main drawbacks of using a "butt-strut" is that if your car is lowered then you'll scrap over speedbumps, as the buttstrut sits even lower than your exhaust. I'm not sure how the exhaust layout on a Z3 compares to that of an e30, but since you're designing this specifically for use on an e30 perhaps there's some room for improvement you guys can come up with.

Good luck. Keep us updated on your progress. I'll let you guys know when I locate the mounting hardware.

[TwoJ's]

Did you double check the overall length of the bar?

You just need to use some trig to find out the overall length. Use arctan(3.125/5.6875) to find the angle, or Pythagoreans (a^2 + b^2 = c^2) theorem to find the length of the hypotenuse.

[NC325iC]

you should make something to tie the front frame together under the transmission it could be as simple as the butt strut but just a different size

[DCColegrove]

^ dude, you are fucking awesome! I will be working on a jig for manufacturing these this weekend. With some luck, I can start a GB soon for about 1/4 the price of those retail ones.

Hmmm, better be sure that there isn't a patent on it, you could end up owing him money...a lot.

The only way to do that with impunity is to move to China and build them there.

[CorvallisBMW]

Hmmm, better be sure that there isn't a patent on it, you could end up owing him money...a lot.

The only way to do that with impunity is to move to China and build them there.

We will be manufacturing our own, based on our own measurements and design. The drawings I requested for only for reference. We will be changing the dimensions too, making them hold tighter to the body to increase ground clearance (since the e30 exhaust does not sit as low as the Z3M exhaust, with which the brand-name model is compatible)

Besides, can you have a patent on a piece of bent bar stock? there's nothing special about it. Just like there are many manufacturers for strut braces, yet each is nearly identical.

[CorvallisBMW]

Next question. Anybody know off hand the size and thread pitch of the subframe bolts that these special female bolt fasteners mount to?


I have a plan on how to make it just need to know what tap/drill to use.

We will be ordering ours strait from Oregon Bolt, so no worries there.

[DCColegrove]

We will be manufacturing our own, based on our own measurements and design. The drawings I requested for only for reference. We will be changing the dimensions too, making them hold tighter to the body to increase ground clearance (since the e30 exhaust does not sit as low as the Z3M exhaust, with which the brand-name model is compatible)

Besides, can you have a patent on a piece of bent bar stock? there's nothing special about it. Just like there are many manufacturers for strut braces, yet each is nearly identical.

Yes you can patent a bent bar, though I doubt that this part is patented however the information exchanged in this thread would be excellent evidence in a US (and most EU) courts.

It really depends on how thorough the original patent is recorded. Patents, trade marks and copyright laws are tricky.

I can tell you though I have several dozen pieces of equipment, photographs and reams of paper sitting in the us patent office archives...I'm hoping someday to recoup the R&D expense whether it be by going into production or...

Your probably safe on this one...I'd look first if I were you though.