[Biginboca]

Small update to the car while I’m waiting for the carbon roof to arrive. I decided to switch to a carbon front lip. Luckily the weave matches the hood and trunk, and all should match the roof too. So that’s worked out so far...





Also I’ve spent a lot of time this week going over any info I can find on the roof swap. Thanks to Corona Virus shutdowns I was able to spend time searching and find the company who makes the adhesive and get it without the BMW tax. From BMW it’s $150 per tube but ordering direct I was able to get the same quantity for about $110. I also found this press release from 2006 by the adhesive manufacturer which has what is basically the directions for the roof install. So that’s really helpful!

[Bimmer_Engineer]

This is an awesome build...the roof sounds very ambitious...good luck!

[E91WAG3N]

Interesting work on the roof skin swap on E92, don't think I've seen it on this chassis before.

If you haven't already, I'd take a look at some of the E46 M3 with CSL roof swaps. There's likely much to learn from since the process is nearly identical. I recall seeing either an E46 or E82 roof swap that required moving one of the brace pieces since the slicktop vs. sunroof cars had a different configuration.

[Biginboca]

Thread update...

Yesterday I spent 2 hours taking my headliner out and prepping the car for glass removal.



This is a surprising amount of work and also brought up an issue I hadn’t seriously considered. My stock headliner really wouldn’t look good without a sunroof. And on top of that once I got it out of the car I could see it was sagging in a few corners and looked kind of dingey.

I started looking online and there’s some great deals on slicktop headliners on eBay ($200 range) but no one willing to ship them. So I was pretty bummed.

On a good note my new $500 roof showed up today. This is what a roof looks like on arrival...



Then I noticed something interesting as I started unwrapping it. It has a headliner with it! SCORE!



So this was a huge win. The roof overall is like C+ condition, but I’ll gladly work with it for the price paid. The fact it came complete with the black roof rack rail covers, a black shark fin, and a slick top headliner made it a huge score for me. The carbon has some marks on it, but I had always figured whatever roof I got would need some love.





I got right to work clearing the glass away and trying to figure out how to separate the carbon. The front and rear edges (front and back windshield edges) went pretty easy. Use a heat gun on the backside (metal) of the roof, not the carbon and this will soften the glue. (You run the risk of turning the gelcoat brown if it gets too hot.). Then a hammer and a metal putty knife and set to work.

It took me about 3 hours going slow and careful to get the front and rear separated.



For the inside edges (roof rack sections) it’s going to be trickier. I haven’t really figured that out yet. I think tomorrow I’ll make cuts on the red lines and then try to rotate the outside edges away from the carbon and use my heat and putty knife/hammer method.



If that works out then it’s time to call the glass guy to pull my windshields.

So I have to say I’m barely into this but it’s definitely a huge project... but so far I haven’t encountered anything which makes me think this swap won’t work out. As far as I know this is the first time anyone has ever swapped a salvaged roof into a car. All the swaps I saw online when researching are new roofs. I have to say knowing what I do now it’s easy to see why. Separating the old roof is a real ass kicker that will likely take me 6-8 hours total.

[colorado.e9x]

I like how they cut right through the glass and shipped it like that lol. Raw asf.

This is going to be interesting.. I wish you the best of luck

[Biginboca]

8 hours in and here’s where I’m at...



The roof is 3/4 free. It’s been a lot of work going slow with a heat gun on the adhesive as I work, which is a lifesaver for this job. Every time I catch myself wanting to speed up and get reckless I tell myself “This Panel is $5,000 from BMW. It’s worth going slow and steady to preserve it.” Have to keep reminding myself that.

This has been a bitch I’m about 8 hours in and haven’t even got the new roof prepped. It will take me all afternoon tomorrow to get the rest separated. Then I have to sand the edges to remove all the old adhesive and prep for install. Then I have to work on the topside and either buff it out or strip the gelcoat and clear coat it.

But even saying all that, right now I’m feeling awesome because I really think this is going to work out. Separating the roof was a huge unknown. Once that is over I’m just following in others footsteps.

[Biginboca]

Plenty of time to tinker lately, so progress being made every day. I’ve got this panel mostly prepped on the mounting surface. I just want to touch up a few areas with fresh gelcoat where it splintered a bit during separation from the original M3 body.

And then I need to sand and spray 3 layers of clear coat on the topside. So will spend this week going through prep on this roof and then planning on starting the install next weekend.

[IllSic_Design]

How was the removal of the roof from the rest of the panels? Was it very difficult to get it separated without damaging the roof at all? Highly interested in this as I know I could also do it myself, but if it's a huge pain to get the roof free without damage I don't know if I want to take it on.

[tlow98]

This is so great! Way to go.

You're making me reconsider my 128i intentions... as there's no OE CF roof for that car :-(

How is the fitment of the Seibon hood? Did you play with shimming up the bumper at all to fill the front gap? I'll bet you can get creative there and really close it up.

Great work so far - I'm feeling the excitement all the way on the other coast!

[Biginboca]

Originally Posted by IllSic_Design

How was the removal of the roof from the rest of the panels? Was it very difficult to get it separated without damaging the roof at all? Highly interested in this as I know I could also do it myself, but if it's a huge pain to get the roof free without damage I don't know if I want to take it on.

The roof removal was a PITA. I read the tech specs for the adhesive BMW used and it said the “typical failure mode” is “substrate failure”, meaning whatever the adhesive is used to attach will typically fail before the adhesive does.

Anywhere the adhesive separated clean from the metal it took the cars paint off with it.

So it’s really annoying to deal with. It took me about 10 hours to get the roof free from the cars body. There are a few places where the edge of the panel frayed a bit. Not through to the top (glossy) surface, the topside of the panel looks good. But in a few places on the edge of the underside there’s loose carbon hairs where the gelcoat separated from the weave and stayed stuck to the metal roof frame. From what I know about carbon fiber you don’t want loose hairs exposed to moisture because it will travel (wick) into them, make them swell and then start to separate and splinter the gel coat.

So I’m going to put some gel coat on these areas to reseal them. They will be resting inside the roof rack rails which definitely sees water.

I found you really need 5 tools (and a ton of patience) to get this done:

Heat Gun
Oscillating Tool with Saw Blade
Putty Knife with Chisel Edge
Flat Head Screwdriver
Hammer

There might be a better way but this is what worked for me...

It’s very slow going, heating a 6” section with a heat gun. If you get the Carbon too hot it will start turning color. Luckily I was working on the inside and none of the color changed areas are visible on the outside. Then I started hammering the chisel in between the inside edge (like if you were inside the car) to open a gap. Then once there was a little gap I get the oscillating saw into it and start cutting adhesive. Once I’ve cut as much as I can with the saw I then heat gun the area again and start hammering a flat head screwdriver into it to pull the rest of that panel apart. It literally took me like 10-15 minutes to separated each 6” of panel. You start going to hard and fast and the risk increases exponentially. The adhesive BMW uses flows like caulk and the hardens into PVC plastic consistency. So it only cuts with a saw you can’t use a blade on it even though it looks like soft caulking on a quick exam.

I’ll post some pics later to show what those edges look like.

I’ll tell you this though, the feeling when the roof finally separated from the last bit of frame was exhilarating! The whole process I still had my doubts that it was really going to work.

Picking up that huge carbon panel when it was free was like holding an Olympic Gold Medal on the podium

It’s a really well made panel btw. Worlds apart from the hood and trunk I bought. The amount of work, hand labor, and quality control that goes into making these panels is nothing like the aftermarket carbon parts we usually buy.

[Biginboca]

Originally Posted by tlow98

This is so great! Way to go.

You're making me reconsider my 128i intentions... as there's no OE CF roof for that car :-(

How is the fitment of the Seibon hood? Did you play with shimming up the bumper at all to fill the front gap? I'll bet you can get creative there and really close it up.

Great work so far - I'm feeling the excitement all the way on the other coast!

The fitment of the hood is probably a B+. The worst is just where you mentioned, the gap above the grills. Shimming it up is on my to do list for sure. Fitting the hood was super easy btw. When I bolted it onto the hinges I could see missing paint on them from where the bolts were for the oem hood. So I just aligned the bolts for the Seibon exactly to the same place on the hinge as the OEM and it lined up perfectly first try.

Seems like whatever Jig they use to construct the hood is dead on.

[StayFrosty]

Looks awesome, great build

[Biginboca]

So kind of at a standstill now. Waiting on epoxy resin and clear coat to arrive.

Seems like salvage parts are never perfect. This roof I got pretty lucky so far. Had some scratches they all came out easy in a few mins with 400 grit wet sanding, except these 2 little chips in the gel coat. So spent a few mins fixing these. Now they just need some epoxy to fill them in and then sand smooth, and then I can clear coat the whole roof.

I’m going to try and do as much of this swap as possible with no professional help. This is supposed to be a diy budget build so I’m planning on clear coating the roof myself when it arrives.

Here’s the roof after some wet sanding. You can see the 2 chips on the left side...



Here’s the chips up close...



I used a pencil eraser and 400 grit to clean the edges...



Here’s where they are at. I think a little epoxy to fill them in and once I clear coat you’ll never know they were there...

[NYBulldog]

Very nice!

[matthewjmoser]

i would recommend ppf after clearing the the roof and allowing it to cure for some time. the sun will take its toll in no time. i have a friend who put a carbon roof on his e60 m5, recleared it him self ( re resin ) and only 1.5 years later it has already starting to turn.

[Biginboca]

So here’s where I’m at with those chips. I can live with this now. I filled them with Spray Max 2K clear coat. Wetting an area duplicates what it will look like after clear coat.

So this panel is all wet sanded and ready for clear coating. Weather has been crap here lately 15-20mph winds and temps 85-90, and humid.

We got a front today and temp is expected to be about 70 tomorrow... at 5:00am. Looks like I’m getting up early to spray this thing lol

[Biginboca]

I just applied 3 coats of Spray Max 2K aerosol clear coat. Waiting on the roof to dry before I can wet sand and polish out the orange peel and some runs tomorrow...

I also have the glass guy coming tomorrow to pull my front and rear windshields. So after tomorrow there’s no turning back!

[Biginboca]

So the roof looks great! Going to install it as is this weekend and then will wet sand and buff it on the car. I want the clear coat to cure for a while before I clean it up. It has a lot of orange peel and some runs but it’s truly a diamond in the rough.

This is how it arrived a week ago. It had a few chips all the way through the gel coat, some big scratches, and lots of oxidation:





These show how it is now after sanding/filling the chips, wet sanding the whole panel, and clear coating:





This has proven to be a lot more involved than I first estimated. I have like 10 hours into separating the roof and now like 6 hours into fixing chips and correcting the gel coat. And I still will need to wet sand and buff the roof once installed.

And I haven’t even started on my car yet lol. Hoping to start working on removing the metal roof Friday.

[W37V]

Biginboca Dude, this is beyond impressive.

Also, I've been using your car as a template on what to do next with mine. I do have one regret - that I never did the n54 manifold like you did. 3im is annoying with torque dips. I just don't want to pay for yet another tune - which I already own.

In any case, amazing work and it takes a lot of courage to even think of doing this.

[Biginboca]

Originally Posted by W37V

Biginboca Dude, this is beyond impressive.

Also, I've been using your car as a template on what to do next with mine. I do have one regret - that I never did the n54 manifold like you did. 3im is annoying with torque dips. I just don't want to pay for yet another tune - which I already own.

In any case, amazing work and it takes a lot of courage to even think of doing this.

Thanks! The torque dips never bothered me as much as the falling flat over 6500rpms. One other nice thing about the n54 that has grown on me is the lack of DISA valves and all the associated issues people seem to have with them on the N/A forum. (Not working, breaking, testing them, etc)

The roof swap is a product of the pandemic. I had fantasized about it for a long time, but if it wasn’t for being able to take my car off the road for a few weeks and having a lot of down time then I would never have attempted this swap.

[Biginboca]

Things just got serious... no turning back now!

[matthewjmoser]

what did you wet sand with before clearing the top? looks great