heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Well, more than a year later and finally got around to finishing up my rear seat weight reduction project. Left off here:

Parts/tools ordered for V2.

Here's the V2 attempt that I tested out on the spare set of seats I took apart:





This worked okay, but it was pretty tricky to get even tension on the seat cover and required it to be permanently modified. So instead, I decided to ditch the Victorian age inspired approach and instead draw inspiration from the RC community.

I came up with this, a 3D printed structure reinforced with carbon fiber tubes, that is made to mimic the original steel frame:



I'm still a pretty big CAD noob, so making this honestly took forever. Fortunately the bigger seat is just a stretched mirror image of the smaller one, so that saved me a good chunk of time. Still, spent way more time on this project than originally expected (what a surprise).

Anyway, to ensure the plastic parts wouldn't break when assembling, I split it up into multiple pieces (which was needed anyway, as the whole thing exceeded the build volume of my printer anyway) so that I could print them all upright:




Yes, the amount of supports is kinda crazy, but this was unavoidable thanks to the print orientation I chose.

Printing everything standing up makes the lip that the leather hooks onto pretty strong, but also makes the structure fairly weak on its long side, hence the CF reinforcements:



I made the sleeves fairly tight around the tubes, but to make sure they wouldn't move, I modeled some clamps/notches into the sleeves where the tubes ended. This allows for the use of a couple small screws to clamp the plastic around the tubes. Here's a cross section showing that off (you can also see a bit of the keys I modeled into the lip that the leather attaches to):



First test prints:




Looking good, so I fired up the print factory and started cutting the tubes. Here's all the pieces needed for the right frame:



Assembled and installed for a test fit:






Super happy with how it came out, looks pretty much indistinguishable from stock.

[heinzboehmer]

Shoot Mark @ Driftec a message. He's super easy to get ahold of, I installed one of his hand brake kits and we chatted a couple times about the install. Nice guy.

Good to know, I'll reach out.

Skimmed through the install instructions for the handbrake kit and it seems very well thought out. Gives me a bit more confidence in the RTAB bracket.

[George Hill]

Shoot Mark @ Driftec a message. He's super easy to get ahold of, I installed one of his hand brake kits and we chatted a couple times about the install. Nice guy.

[heinzboehmer]

Is the toe adjustment range an issue?

Yeah, at my current ride height (higher than most track cars), I can't get less than 3/32" toe in at -2 deg camber in the rear. I could go lower and get more sensible toe at higher neg camber, but I was hoping to go back to stock height instead, so those brackets are probably my only option.

[bigjae46]

Oh also, came across this product that should allow me to run the rear toe + camber I want at a higher ride height: https://drifttec.co/products/high-to...ets-e36-e46-z4

I'm still undecided on them though. My biggest concern is binding, since there has to be a lot less clearance from the bracket to the bushing to allow for the extra toe adjustment. This image shows the difference in geometry pretty clearly:


I'll likely just leave it alone for now and reevaluate when I change springs/dampers/get an alignment.

Is the toe adjustment range an issue?