Dreaming: Miata-style butterfly brace

[92 mtechnic cabrio]

What kind of ground clearance would the e30-version butterfly brace have?

two of my miata friends have lowered miatas and have had their butterfly braces ripped off (along with damage to the cars' original parts from having the brace ripped off the car)

can't blame FM for that though, or anyone but themselves, they have the same beliefs in ride height as I do

[Wishno87]

good insightful post

[Coco Savage]

interesting.

[xLibelle]

I have a close friend that works heavily with miatas and we have discussed this component and the possibility of something like it for the e30 but investigating the potential design needed.... lets say it would be difficult to produce the outcome thats gained with the miata.
We've heard a bunch of good feedback from the FM belly brace and the design of that car benefits greatly from it. The e30 on the other hand is a totally different design than the miata though.
Here's the reason for its need in the Miata. The car is based around subframe design and the Power Plant Frame (PPF). The body just ties the frames together at key points with bushings. (there's 22 of them in total btw, thats a lot of rubber.) Remove those few bolts and you can pull the body off and end up with this:

The butterfly is key to triangulating the rigidity of the entire car. Something the e30 could possibly use, but doesnt have the problem that the miata does.

A couple points on the e30 are worth mentioning though - front end and rear end... obviously. The control arm bushings can be solidified from moving toward or away from each other... explained here. (And in Red below)
The rear subframe motion can be dealt with by installing solid SF bushings. But also the addition of something like what the Miata rear subframe has that ties it to the body of the car is feasible. The two bars can be seen in the miata belly picture in rcko's post.
The rest of the bodies structural rigidity is addressed with heat shielding and other brace work below the drive shaft, above the exhaust. But here could be a suggestion for realistic bracing, though i dont know if it would be worth it. (In green)
The quick sketch is not a proper design, but rough idea at what points describe possible linear deflection... or whatever.

[funcrew]

That quote change my mind entirely. I think you should revise that whole thing. I will not be putting some chassis brace that can be modified with tin snips on my car, Sounds like race seat brackets made of chewing gum and used foil from making potatoes.

My bad - In case it wasn't obvious, I was just joking around. The Miata guys swear that this piece transforms the chassis - its made from heavy gauge stainless steel, laser cut and cold-formed on a mega$ brake. In other words, the proposed version could be several times stiffer than the well-designed but lightweight E30 belly pan.

[Farbin Kaiber]

This is quickly becoming a "Tornado Brand Air Intake Horsepower Mod" Thread.

[atomic]

^ AGREED Farbin Kaiber

if a brace can be trimmed with tin snips and JB welded back together, you might as well be using balsa wood and elmers glue then...

[Farbin Kaiber]

The brace is/will be a sheetmetal piece - you can just use tin snips to clear your swap, then JB-Weld the trimmed off bits back on as gussets to stiffen up what's left.:grin:

That quote change my mind entirely. I think you should revise that whole thing. I will not be putting some chassis brace that can be modified with tin snips on my car, Sounds like race seat brackets made of chewing gum and used foil from making potatoes.

[funcrew]

agreed... and the 6-speed....

The brace is/will be a sheetmetal piece - you can just use tin snips to clear your swap, then JB-Weld the trimmed off bits back on as gussets to stiffen up what's left.:grin:

[BeirBrennerE30]

I'd take one if it will clear an s52.

agreed... and the 6-speed....

[duodvlhntr]

Fantastic idea! I wish I could help with the R&D. I think something similar to the Miata's would stiffen it up a lot. ...Man, this is hard to do without drawing something...

[Farbin Kaiber]

Shhhh......

[atomic]

I'd take one if it will clear an s52 and most importantly made of carbon fiber!

[Farbin Kaiber]

I'd take one if it will clear an s52.

[devonjordan]

I would totally be in for one of these! My vert needs all the stiffness it can get!