heinzboehmer's 2002 Topaz 6MT Coupe

[Obioban]

I think it'll go in even being completely rigid, I don't recall ever having to bend a coupe. The door frame is larger on a coupe than a sedan and they come out a sedan without bending as well. Worst case you take the door off, 3 bolts and a wiring connector, bingo bango.

I will admit, I did not think of taking off the door.

[heinzboehmer]

So the cars I've pulled these from are junkyard e46 non-m with shit all over the place. I think without a seat and door would help free up space, but I'm going to tinker around with the loose headliner I have and see because now I'm curious.

Other areas I would think about (not necessarily an issue) is how it conforms along the ceiling and slides under the window moldings, and the panel in the back where the headliner curls over. As long as the fit is good i'm sure it's not a huge deal but these are areas I recall some flex aiding.

I'm guessing these reasons why a certain shop took 3 years to develop this, and unless they purchased up all the limited(and now not really available I have a backorder in) BM134 this would be a non-oe fabric.

Yep! The more I stare at this, the more it becomes obvious that there's no way a replica is gonna be better in any way than the BMW part. Weight, NVH, ease of install, etc.

BUT, being able to buy something beats not being to buy anything, so still seems like a worthy endeavor.

I can see how replicating these the traditional way (i.e. trashing a part(s) to pull a mold) drives development costs way up and makes the retail part end up priced like they've priced it. However, I think approaching it from the digital world would lower those costs significantly. Development cost basically becomes materials for the mold and a couple prototypes, then it's just a matter of cranking out parts.

[bavarian3]

So the cars I've pulled these from are junkyard e46 non-m with shit all over the place. I think without a seat and door would help free up space, but I'm going to tinker around with the loose headliner I have and see because now I'm curious.

Other areas I would think about (not necessarily an issue) is how it conforms along the ceiling and slides under the window moldings, and the panel in the back where the headliner curls over. As long as the fit is good i'm sure it's not a huge deal but these are areas I recall some flex aiding.

I'm guessing these reasons why a certain shop took 3 years to develop this, and unless they purchased up all the limited(and now not really available I have a backorder in) BM134 this would be a non-oe fabric.

[heinzboehmer]

Link not working

Oh hmm, looks like they deleted the post?

Link still works on my phone, so maybe the app has it cached?

Whatever, here's a few screenshots:

[bigjae46]

Bryson sent me this: https://www.instagram.com/reel/DYAGESosIlI/

Looks like their strategy is similar?

Link not working

[heinzboehmer]

What I would do is apply a layer of surface veil with epoxy on the original part to create a good surface to pull a mold from. That is how I made a mold for the fiberboard E9X M3 panels that go behind the front bumper.

The bad thing is you have to destroy the part.

Bryson sent me this: https://www.instagram.com/reel/DYAGESosIlI/

Looks like their strategy is similar?

[bigjae46]

The 2M one? I'm very curious to see what they managed to pull off, how they made it, how much it weighs, etc. Staring at this part has made it very obvious that it's not trivial to get it right

What I would do is apply a layer of surface veil with epoxy on the original part to create a good surface to pull a mold from. That is how I made a mold for the fiberboard E9X M3 panels that go behind the front bumper.

The bad thing is you have to destroy the part.

[heinzboehmer]

I've definitely replaced a headliner on a coupe without removing the door. I MAY have removed the seat or laid them all the way back, but I've done it without a door removal. For whatever it may be worth

Also on the e46 m3 Facebook group, someone said they were going to make slick top headliners at about $1k soon. But I didn't pay too much attention to it

The 2M one? I'm very curious to see what they managed to pull off, how they made it, how much it weighs, etc. Staring at this part has made it very obvious that it's not trivial to get it right.

You don't need to on a stock headliner, lay the seat back and open the door and it goes out the passenger side no problem.

What I meant was that IF you needed to bend it to get it out and a rigid headliner wouldn't fit then you could take the door off easier than pulling a windshield. Again, I don't think that is necessary but some people were concerned in the various headliner threads present right now.

Yep, I like your line of reasoning. Feels safer to go for max stiffness in the part and remove the door if necessary during install. Seems like much less hassle in the end than trying to live with a floppy headliner.

Unless you make it too stiff and it resonates at highway speeds 🙃

If that ends up being an issue, it might be worth looking into redesigning the motion sensor bracket so that it double-sided-tapes to the roof, to constrain the part in the middle. Hopefully that drives the resonant frequency way up into a range that a street car will never see in practice.

[George Hill]

I've definitely replaced a headliner on a coupe without removing the door. I MAY have removed the seat or laid them all the way back, but I've done it without a door removal. For whatever it may be worth

You don't need to on a stock headliner, lay the seat back and open the door and it goes out the passenger side no problem.

What I meant was that IF you needed to bend it to get it out and a rigid headliner wouldn't fit then you could take the door off easier than pulling a windshield. Again, I don't think that is necessary but some people were concerned in the various headliner threads present right now.

[YoitsTmac]

I've definitely replaced a headliner on a coupe without removing the door. I MAY have removed the seat or laid them all the way back, but I've done it without a door removal. For whatever it may be worth

Also on the e46 m3 Facebook group, someone said they were going to make slick top headliners at about $1k soon. But I didn't pay too much attention to it

[George Hill]

I think it'll go in even being completely rigid, I don't recall ever having to bend a coupe. The door frame is larger on a coupe than a sedan and they come out a sedan without bending as well. Worst case you take the door off, 3 bolts and a wiring connector, bingo bango.

[0-60motorsports]

Thats excellent.

[heinzboehmer]

Yeah the stiffness of the part will be an interesting thing to figure out. Too stiff and it won't fit through the door, too bendy and it'll flop around when driving, since it's not really held by anything in the middle.


Also, have started working on the CAD model and wow, it's been a struggle.

For the previous scan, I hung the part vertically from the ceiling, thinking that that would allow it to keep its shape. Unfortunately, mirroring the part along its short axis in the digital world made it very apparent that this assumption was incorrect.

I messed around with it for a while, thinking that I had my coordinate axes slightly tweaked, but eventually came to the conclusion that the part was deformed when I scanned it. This is as good as I could get it:



That gap is roughly 20 mm across. Nowhere near acceptable.

So, I gave up on that scan and redid it. This time, I built a professional fixture so that the part could lay horizontally on the ground without distorting:



For anyone following along at home, you'll need exactly these parts for max precision:

• 4x Dinner plates
• 1x Flooring sample
• 2x Varied candles
• 1x Folded over MF towel
• 3x Assorted rolls of tape

I set everything up so that the headliner was juust barely resting on the plates. They're not there to provide any support, but rather to provide flat references for plane alignment in CAD.

Newest scan is muuuch better (have updated the previous link):



Gray is the scan and yellow is the mirror. Not entirely perfect, but I didn't expect it to be. Can absolutely work with though.

Now it's just a matter of getting lost in surface land and coming out the other side with a model.

[bigjae46]

You can get the the stock one in that way, but it’s quite bendy.

Maybe that's why the 2M one never took off? The headliner would need to be installed when the roof is installed and most that would buy it already have a roof installed.

[Obioban]

Should be a little bendy but not much. Can't get it in through the door opening with the seats removed?

You can get the the stock one in that way, but it’s quite bendy.