Another F81 Build Thread

[attbimmer]

I think it took longer to remove the wiring harness from the car then it did the drive train. Overall though it came out without issues, just fiddling with endless clips. Out of the 100s I think I only broke about 10 or so.



Just a few things left to complete stripping the body. Then the real fun begins.

[WedgeSalad]

Godspeed

Cant wait to see what direction you take it

looks like its local too, if you need a hand feel free to hit me up

[attbimmer]

Had just a little time tonight, so thought I'd at least quickly pull out the sunroof and curtain airbags. Then looked closer and saw a few dozen rivets would need to be drilled out as well as some interesting looking clips that held parts of the airbag. After futzing with the first clip to figure out best angle and tools to use the rest came out pretty easily. The rivets are pretty thick, but are soft aluminum so drilled out relatively quickly.

After all the airbag and about 16 metal bracks were removed, the sunroof unbolted and was out in 5 minutes. It comes out in 2 parts with the tray, motors, and moving parts of the glass and shade as one large part and then a smaller section that has the second piece of glass that doesn't move. The seal that goes around the glass and metal of the roof is glued on real well, so that will be fun to remove.

Could probably have left a few of the brackets in, but at this point I'm beyond deep into this and would like to make it look as close to factory as I can within some semblance of reason.

[attbimmer]

Getting closer. On the inside about all that is left is about a million little plastic plugs in various places.

[attbimmer]

Haven't had a lot of time the last week or so, but with an hour or 2 here and there I was able to finish stripping down the wagon body. Even though it seemed close last time I posted, you look closer and find a few things here and there and they all add up. I pulled out the fuel tank, filler and lines, main battery wire, gutted the 4 doors, took out enough plastic plugs to fill 3 Ziploc bags and took off the rear hatch glass and roof rails. I also drilled out the welds for the rear diff guard. I used a special drill bit that cuts around the spot weld and automatically stops at the right depth. My first time using it, but it worked really well and didn't cause any damage to the body underneath.






So now I'm going to turn my attention to the M3 donor for a bit. I need to get the rear fenders off it so I can get the wagon body over to the body shot in the next couple weeks. Right now I plan on having them do the rear fenders first and paint the engine bay. I'll then pick it up and can start transferring over suspension and a lot of the underbody items and get the rear bumper sorted before it goes back for full paint.

I also took the M3 out for a short drive before I take it apart just to make sure overall things are working. Was my first time driving it. I put the stock tune on it before I drove it. That helped quite it down some, but it is still super loud on throttle. Getting cats back on it should sold that. Overall everything worked, except the parking sensors for some reason and the passenger heated seat. I recall a couple codes related to them and will look a little deeper before fully taking it apart. For now though I pushed the wagon over and backed the M3 in and will get started on it soon.

Looking at the carbon inserts on the front bumper, I'm guessing those are put on at the port with betalink as well and won't come off easy. I don't necessarily dislike them, but since I'm painting the car would be nice to have them off for paint.

[attbimmer]

A bit of dejavu as I begin taking apart another F 3 series. Intention is to take off enough to allow access to cut off the rear fenders so the wagon body can head to round 1 at the body shop.

Started with the nice and simple task of removing the wheels. Fronts came off easy, but there were 15mm spacers on as well that were very corroded into the hubs. Previous owner or whoever worked on it obviously didn't believe in anti seeze. After some soaking, heat and banging they finally came off. I cleaned up the hubs and spacers before moving on. The rear wheels on the other hand were so over torqued that it actually broke the socket I was using. I had to hold a torch on each lug, so a minute or so before they would eventually give way with a breaker bar. I've come across plenty of over torqued wheels over the years, but this one was the worst I'd seen.

After that though, was all very straightforward. Removed the wheel well covers, side skirts and rear bumper cover and carriers. At this point having the 2 cars side by side was able to start to see first hand the specific differences. On the rockers you can see about mid rear door where the mounting slots for the carrier change direction. On the F30 they stay the same all the way across. The F80 actually uses the F30 M sport skirt carriers for the front and middle and just the rear is M3 specific.

Tomorrow will spend some time measuring and marking before start cutting the rear fenders. Will leave plenty of extra so that there is a lot to work with as it gets eventually trimmed down to just what is needed.

[attbimmer]

After some time looking I decided to just dive in and start cutting. Was originally going to just cut out the M3 fenders and drop off as is to the body shop, but a lot of the fun in these projects for me is learning new skills along the way and I like to do as much as I possibly can myself while still ensuring I get a good result.

Since the wagon is already stripped, I started there. Was able to cut out large sections of the outer skin on the wheel arches and along the bottom rail. I also drilled out all the spot welds along the door edge. There are just a few spots still holding parts on that I didn't have a small enough grinder to get into. Ordered that and will be able to finish up this weekend. Once those large parts are out I'll be able to drill out the spot welds along the bottom rail and then decide how to approach the inner wheel wells.

At this point I'm leaving quite a bit of meat on still so that when it comes to fitting the M3 fenders I'll have a lot to work with to fine tune.

I'm also still undecided on how I will approach the inner wheel wells. Cut the entire section out and buy M3 inner sections to weld in complete or cut the wagon and M3 arches in half and weld together in the middle. Will start with the latter and if it doesn't look like it will work out well then I can always switch to using full new M3 im er wells.

[attbimmer]

It's a bit late, so will post details later, but big step forward. I've now officially ruined 2 not perfect, but functional cars. 😁 Was definitely a bit nervous about this, but feels great that it came off without any damage. One more to go and then ready for trip to body shop.

[attbimmer]

Another late night and another fender removed. Can now just focus on final cleanup this weekend between many other things going on and get everything packed up for the body shop.

[Boznien]

This is amazing. A lot more work goes into these custom builds than I thought. I love that you're documenting just about everything! This is going to be sweet.

[attbimmer]

Wanted to provide a bit more details on removing the rear fenders from the M3. I cut quite a bit extra around all the exterior edges and avoided drilling any spot welds that I cut and instead cut extra and then carefully drilled out spot welds from the inside inorder to keep the exterior fender as clean as possible. I did the opposite on the wagon where the goal was to keep the wagon body as clean as possible and didn't care about the fenders.

On the wheel wells there are 3 areas where they are welded to the body supports. 1 at the forward lower base, 1 at the upper forward area near the door latch and 1 near the c pillar join. Each had a series of spot welds that had to be drilled out from underneath. No way to get at them elsewhere.

End result though was inner and outer fenders coming off together and will putting them into the wagon in the same way to keep the outer lip factory and the rest will be fully hidden anyway.

Here are a few pics showing the areas that needed to be drilled out in the wheel wells.

[attbimmer]

Big milestone yesterday, got the wagon body loaded up in trailer and dropped it off at the body shop along with the M3 rear fenders. With the wood frames bolted to the body I was able to tie down just to the wood frame and avoid pulling on a section of body that wasn't meant to be pulled.

The body shop is going to start working on the rear fenders first and will be painting the engine bay to replicate a similar to factory matte finish. Once rear fenders and engine bay are done I will likely pick it up again and start moving over suspension, fuel tank and some lines that run underneath. I'll also then sort out the rear bumper before taking it back to finish the rest of the paint. Front subframe will also need to be in to allow welding in 2 extra subframe mount points.

In the engine bay on the front right side there are a couple brackets that are no longer needed and one that needs to be moved over from the M3 to support one of the air boxes. It's odd, from the factory seems BMW just cuts off 2 of the brackets rather than drilling out the spot welds and removing the full bracket or not installing them in the first place. I just drilled them out and removed the full brackets in order to keep it a bit cleaner.

[attbimmer]

Body shop got right on it and the right side inner wheel well is fully on and the outer is tacked in. Long way to go still, but very cool to see things coming together.

[attbimmer]

I started some work on the rear bumper and carriers. So far just rough trimming of each with plenty of extra still to trim, but did enough to get an idea of how they will come together. Also stopped by the body shop with the bumper pieces so that they can use them to confirm fit and alignment of the rear fenders before fully welding them in. The left side fender is also backed into place.

While the body shop is working, I'll next turn my attention to a few issues on the M3. PDC isn't working (camera does), just prints error on screen that park assistant unavailable. Also the passenger front seat heater isn't working. Lights on the switch don't come up at all when pressing it. All the other seat controls work ok. Figure it is better to sort these out now before I fully disassemble to avoid having to take things apart again after rebuilding on the wagon body.

[attbimmer]

While the wagon is at the body shop here and there I've been starting to take apart the M3. Also checked the codes that were present.

I setup ISTA on an old laptop and that gave me better details.The parking assistance issue is caused by front PDC sensor fault. Even after swapping sensors the issue follows the same position. The front wiring harness has obviously been modified likely as part of the original accident rebuild so I will just replace it and then check again. The front passenger seat it shows seat heating front passenger missing LIN component. The seat heating connects to a little module under the seat that is also used in the rear seats, but swapping them didn't change anything so will need to look into that more.

I started taking apart the front end to see what other damage I may find. First issue I found was the front edge of the front subframe on the right side has been squished in the accident. When fixing it they just drilled another hole so that they could still bolt on the lower part of the front support. Functionally it works fine since suspension was not impacted and the support just holds coolers and non structural elements up front, but since I'm taking everything apart anyway I will replace it. There are a few other misc plastic parts or brackets that have some minor damage as well that I will replace. A local salvage yard has a good subframe I will go pick up and see what other parts I need that I can find there.



I pulled off the exhaust as well. The m performance exhaust is certainly pretty light and seems well made. I'll likely keep it for now. I did also find the secondary cats were also gutted on this car. No wonder the farm thing is so early splittingly loud. It is effectively full straight piped when the valves are open.

Not sure what brande the aftermarket down pipes are. Perhaps someone on here knows. They have a G logo visible from below. If anyone wants them or burger motorsport intake pipes let me know.



A local forum member had most of the stock intake parts available that I also picked up to eliminate the aftermarket gold painted one that was on the car.

[attbimmer]

After picking up the new front subframe I stopped by my body shop. They have the rear fenders fully installed and primed and were finishing up installing the additional supports in the front.





I also dropped off the front subframe with the 2 support mounts that need to get welded in to the body and they will take care of that and then paint the engine bay as soon as I decide on the final color.

[alex2364]

Looks great so far! What color did you decide to go with?

[attbimmer]

Originally Posted by alex2364

Looks great so far! What color did you decide to go with?

It will be red. They sprayed a card of imola for me. I'm having them do a few more shades as well just to compare them side by side, but will probably end up imola. I can't decide on an exact shade of blue that I'm sure I would like as much as a red.

[Boznien]

Originally Posted by attbimmer

It will be red. They sprayed a card of imola for me. I'm having them do a few more shades as well just to compare them side by side, but will probably end up imola. I can't decide on an exact shade of blue that I'm sure I would like as much as a red.

No Avus Blue?

[attbimmer]

Originally Posted by Boznien

No Avus Blue?

Maybe for the next one. 👍

[swagon]

What are you doing for rust protection?

Great progress so far. The G logo on the cats is Gintani.

[attbimmer]

Originally Posted by swagon

What are you doing for rust protection?

I assume you mean for the areas that have be cut and rewelded?

So far everything that has been welded has been separated enough so that everything could get cleaned up and primed similar to what the factory does. Areas that directly got welded used a weld through primer. Seam sealer will go back over all edges again trying to mimic what the factory did. The back side of areas that got welded, mainly the upper part of the rear fenders are still accessible so that a coating could be added on top to ensure there is not exposed metal.

I wasn't planning to add anything beyond that, but open to suggestions. While the body is stripped may not be bad idea to do something extra.

Thanks also on the downpipes.