heinzboehmer's 2002 Topaz 6MT Coupe

[0-60motorsports]

Yeah I'm pretty excited about it. Will share all the design files when I'm done in case anyone wants to recreate this on their car.

Awesome Thanks! Wil just have to find someone in the USA to print them for me in the correct material.

[heinzboehmer]

Also, forgot to mention earlier, but I also designed this top clamp to go over the stock strut bar. The purpose of it is add rigidity to the bottom sheet metal clamp. There will be a torque trying to bend it away from horizontal (or close to) and this clamp should help with that. However, it's totally possible that the final geometry makes this clamp essentially redundant. We'll see.

[heinzboehmer]

That E86 Brace idea is perfect! Good thinking. I am just imagining how easy it'll be to work on the engine as you said. Thanks.

Yeah I'm pretty excited about it. Will share all the design files when I'm done in case anyone wants to recreate this on their car.

[0-60motorsports]

That E86 Brace idea is perfect! Good thinking. I am just imagining how easy it'll be to work on the engine as you said. Thanks.

[heinzboehmer]

Braces arrived today, this should turn out pretty great:



I will need to shorten the ends a bit and redrill the holes for the fasteners. Fortunately the flat part is pretty long, so I'll have space. The shortened braces should line up pretty much perfectly with the base of the windshield. I plan to keep my windshield attachment point pretty tight to the existing structure, so that the braces are as parallel as possible to the plane of the windshield.

Also, here that crash safety feature I was talking about:



Will definitely sleep better at night knowing that that exists.

[heinzboehmer]

Sneak peek at side project #57: Took the M3 to the dentist today and got it fitted for braces:





Plan is to design a windshield cowl attachment point with two studs that I can fasten E86 Z4 braces to. Many reasons why I chose those, but it basically boils down to them being BMW parts and having a notch at the bottom that allows them to buckle in a front end collision. BMW didn't design the E46 chassis to be seeing significant rearward force in the middle of the windshield and I'd very much like to keep all the engine bay stuff out of the passenger compartment when I go head on into a wall.

Oh and the biggest benefit of this design is that it'll be three piece! Definitely gonna be less stiff than Slon's (although hard to quantify by how much), but it'll make working on the engine so much nicer. Won't have to be worrying about losing my alignment settings whenever I'm in there

To attach the braces to the strut towers, I designed these brackets:




The tab going to the top hat stud is there to help reinforce the stock cast aluminum piece. It still might now survive though. If it doesn't, I'll redesign the entire thing and get it printed in an appropriate material.

Anyway, waiting on the E86 braces to show up. Will update as I get farther along with this.

Oh! I did also manage to (almost) retrofit the euro cubby into one of my test dashes:



Need to tweak the vinyl cuts and dies a bit, but it's getting there. More to come...

[WestBankM4]

Headliner is a nice pickup Heinze! I've been keeping my feelers out for one, just so I can throw it in storage for my roof project in 2055.

[George Hill]

My best guess is that it came from the foil that seals the oil bottles. Definitely looks very similar:

That was my guess too.

[heinzboehmer]

Annual oil change and PS "flush" (suck fluid out of the reservoir and replace) done.

Fun fact, this is the first time in many years that I reached the mileage limit of the interval before the time limit (5k mi or 1 year, whatever comes first). I actually ended up ~300 mi over the interval exactly a year after the last change, awesome. Feels good to have the car "re-streetified", as I'm actually driving it now.

Anyway, nothing of note during the service except for this thing that I found inside the oil filter. Interior trim nut/clip for scale in the second pic:




Non-magnetic and a bit too shiny/flimsy to be cast aluminum. My best guess is that it came from the foil that seals the oil bottles. Definitely looks very similar:



Not worried about it really, oil filter did its job. Track day in a couple weeks, so if the engine explodes, well, I guess I should have been worried

[heinzboehmer]

Cleared out the local junkyard of all their (remaining) lower left dash sections. No black interior cars there, so didn't feel too bad about chopping up some perfectly good dashes



One of the cars I stole parts from was interesting. Interior was in great shape and the exterior was covered in small sections of tape, almost like telltales. It also had crash damage that looked suspiciously like it had come from some kind of front overlap crash test. Not sure who's crash testing an E46 25 years after they were released, but cool to see.



Anyway, time to knock out the remaining CAD stuff.

[heinzboehmer]

Designed some more concentric templates for cutting:





The innermost one is meant to act as a vinyl cut template. The plan is to just stick an oscillating cutter in and plunge it through all three dash layers. The vinyl will need trimming after forming, so the shape at this point is not super important. Although I might tweak the profile in the future.

The middle template is for drilling pilot holes for the corner radii of the inner layer cut. These holes are meant to only go through that inner dash layer, not the foam or vinyl.

However, I didn't use either of these new templates for the first test. The inner layer is cracked on the dash that I'm experimenting on, so not worth going through the trouble if I'm not gonna be able to take measurements off of it anyway. Instead, I just cut a square hole through all three layers using the previous sharpie marks as guides.




And it fits! Looks pretty good:




Aforementioned tabs line up great as well:



I also dug out some of the foam so that I could get a sense of how much the vinyl will need to stretch:



Unfortunately, I'm now at a point where I can't really do much more in the real world. Next up is modeling the outer dash surface and the entire cubby using the scans as references.

Plan is to fit them together in CAD and then work out the appropriate shape that the vinyl need to be pressed into. I plan to design and print that shape, fit it up to a (clearanced) dash and iterate on it until I'm happy. Once it looks and fits well, I'll use the negative of it to design the press die.

[heinzboehmer]

Which software are you using to design and model the parts?

I've been using Onshape. It's pretty great for most stuff, but I do have to say that it really struggles with the higher resolution scans.

[ac427]

Which software are you using to design and model the parts?

[heinzboehmer]

Finally some euro cubby progress.

Started by modeling and printing a perimeter that represents the smallest hole I can cut in the inner dash layer, while still allowing the front of the compartment to fully articulate. Clearance between the reference perimeter and cubby is way tighter than I actually want to make it, but this piece is just meant to serve as a real world, tangible reference for myself:





Next came the cutting template for the inner layer. I modeled the inside of the dash (actually a negative of it) using one of the many scans Bry5on and I took as a reference. Then did my best to approximate the cut lines using images of the euro dash:





Managed to nail the geometry on the first try!

Guess that's kind of the expectation when referencing a very accurate scan, but still felt great to pull this thing out of the printer and have it just fit:





Hard to tell from the pics above, but the template indexes on a couple of the dash features and is held in place by the screws that normally hold in the footwell plastics. This should make the cutting operation fairly precise and very repeatable.

(also, photographing matte black plastic is no fun...)

I then grabbed another (cracked) section of a dash, verified that the template fits just as well on that and marked the cut lines with a sharpie:



Looking more and more similar to bmwfnatic's dash!



I also checked the cut marks using the reference perimeter piece from before. Keep in mind that the cut will happen on the outside edge of the sharpie marks, but the minimum perimeter corresponds to the inside edge of the reference piece:



I might open up the tolerance on the cut lines just a bit, but still not sure. Placing and fastening the cutting template seems pretty repeatable, but I'm going to need to practice on a few dashes before I can say for sure that the cut lines always end up in basically the same spot. If they do, then I can keep them where they are. If they don't, I'm gonna need to mess with them a bit.

The one thing that I cannot move around is the bottom cut line (closest to the existing screw holes). The cubby has two tabs that hook onto that edge and keep it in place. Too much space between the cubby and that edge means its bottom will slide forward when you go to open it.

Next up is actually cutting that section of the inner layer out, digging out the foam from underneath and starting to mess with the vinyl. I should be able to cut out most of the vinyl and just push the cubby in to give myself an idea of how much the vinyl needs to be reshaped.

[heinzboehmer]

Old headliner foam removed. I opted to buy some dish brushes and try to remove it manually in an attempt to cut down on the mess. The brushes I got had some plastic scrapers built into their heads which worked extremely well for scraping the foam up. I then used the actual brush part for the harder to reach areas.





The foam was easy enough to remove, but there's still a layer of old glue on the thing. I don't think I can remove it without damaging the material underneath, so just going to leave it.

There was also a bit of mold staining on the bottom corners. Tried spraying with some isopropyl alcohol and then hitting it with the brush. Got most of the stains out, but was also starting to mess up the material underneath, so I stopped. Good enough:




That's it for now on the headliner. Once I manage to buy the fabric, I'll give it a quick pass with the drill brush attachment (to get any foam that I might have missed by hand), stick it in a bag with the ozone generator, give it a quick scuff with some sandpaper and reupholster it.

Also, since the slicktop homelink bracket is NLA, I decided to just get a homelink mirror instead. Ended up with a ridiculous amount of them, as I also retrofitted a homelink 4 module into a friend's mirror:



Along with the mirror, I also built an E8x/E9x dashcam adapter harness thing for said friend:



M3 got a short, grey clown nose mirror with the homelink buttons. It also came with a compass, but I decided to disable it. TIS wiring diagrams made it seem like the compass runs off of the shared 12V rail in the mirror, so I didn't even try pulling wires from the connector to see if one of them disabled it. Instead, I just removed the GND jumper from the daughter board of the compass screen (J6) so that it can't turn on. I also put some tesa tape on top of the screen, as you can just barely make out its outline if the light hits the mirror just right. much harder to do so with the tape:





And lastly, just a quick note to my future self: guitar pick is absolutely the best way to open these things up. Slip it in somewhere (homelink mirrors have a nice little cutout in the surround near the buttons), then run it around the perimeter of the mirror. Pick is flexible enough to get underneath the edge of the surround and also soft enough to not leave any marks: