Another F81 Build Thread

[swagon]

Originally Posted by attbimmer

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.

I'm not an expert on this unfortunately; I've had my F80 coated with Würth anti-corrosion wax of sorts up in all the cavities, fender liners were off, etc., and when I saw your photos, they reminded me of this

I'd try look up something similar since the car is in bits now. And these things are great in snow (and salt's a bitch)

[attbimmer]

Originally Posted by swagon

I'm not an expert on this unfortunately; I've had my F80 coated with Würth anti-corrosion wax of sorts up in all the cavities, fender liners were off, etc., and when I saw your photos, they reminded me of this

I'd try look up something similar since the car is in bits now. And these things are great in snow (and salt's a bitch)

I'll look into it some. I'm in Southern California and the car will likely never see snow or salt at least while I own it, but like you said while it is apart.

[attbimmer]

After thinking about it a bit I decided to have my body shop do the transmission tunnel modificationa now as well so that the RWD trans mount bolts up properly. That means I really need to tear into the M3 because I need to cut out a section of the body and front driver's seat mount.

So last night I took out the center console and dash. Doing it for the second time it went quite quickly. Not too much different between the 2. The M3 has lane departure sensors, so you lose the little cubby under the main light switch. Also there are the extra knew braces on the center console, but it still comes apart the same way.



Today I pulled out the engine and trans. I had previously pulled off the coolers and found various plastic parts the were cracked or broken and will need to be replaced. Really not too many things to disconnect from the engine to the body before it is ready to come out. Since my fancy chassis dollies are at the body shop I put the front subframe back on with wheels so that if I need to I can still move it around. After the engine was off I also had to reposition my lift again due to the weight loss up front.

[attbimmer]

I was also comparing the strut bar mount points between the wagon and M3. In order to fit the larger aluminum brace from the M3 there is a rivnut on the outside edges of the body on the M3. In the F31, the hole for it is already drilled, but no rivnut. That is easy to add.



There is additional bracing that goes back from the strut to the base of the A pillar. At that point there is a different type of bolt hole welded in some how. Can't see behind it and doesn't look like that part can be ordered individually. I'll likely cut the M3s out to see what it looks like, but may use a rivnut there as well. That probably isn't as strong though, so will think about it.

[attbimmer]

I'm quite surprised at how poorly at lot of bolts on this car were tightened. Some bolts are hugely over torqued and others are barely more than hand tight. I'm certainly glad I'm taking everything apart anyway and someone else didn't buy this car and just drove it as is. There are also various places where things were poorly repaired and just random bolts used or things just zip ties together. All of that will be addressed now. Certainly makes it easier that I have a full cars worth of extra bolts/clips/...

One of the trans mounts was completely broken and not held together at all, so those will both be replaced. The engine mounts seem to be fine. One of the right front suspension ball joint boots is torn, so will have to take care of that as well.

[attbimmer]

Let's see how well you guys know your reds.

[swagon]

1. Toronto Red
2. Melbourne Red
3. idk
4. Imola

[swagon]

Originally Posted by attbimmer

I'm quite surprised at how poorly at lot of bolts on this car were tightened. Some bolts are hugely over torqued and others are barely more than hand tight. I'm certainly glad I'm taking everything apart anyway and someone else didn't buy this car and just drove it as is. There are also various places where things were poorly repaired and just random bolts used or things just zip ties together. All of that will be addressed now. Certainly makes it easier that I have a full cars worth of extra bolts/clips/...

One of the trans mounts was completely broken and not held together at all, so those will both be replaced. The engine mounts seem to be fine. One of the right front suspension ball joint boots is torn, so will have to take care of that as well.

There are many horror stories of salvaged US vehicles that were imported into Europe and subsequently very badly repaired. I'd say more than half of the F8x for sale in Germany at the moment are salvage-titled US imports.

[attbimmer]

Originally Posted by swagon

There are many horror stories of salvaged US vehicles that were imported into Europe and subsequently very badly repaired. I'd say more than half of the F8x for sale in Germany at the moment are salvage-titled US imports.

I'm not too surprised. A few different salvage M3s I was close to buying on copart all ended up going to Europe.

[attbimmer]

I finished pulling out the rest of the dash today so that I could remove the front carpet section and enough of the wiring to be able to safely cut out the front seat mount and floor section to complete converting the tunnel to RWD. Some gross stuff under the carpet in the M3. Definitely some food and spilled soda remains. Despite the wagon having way more miles, it does seem like it was better cared for. So far nothing that can't be cleaned up though. Will drop off the floor section along with trans mount and the rear bracing at the body shop so that everything can get bolted in place to ensure the new tunnel section is welded in the right spot.

[attbimmer]

Originally Posted by swagon

1. Toronto Red
2. Melbourne Red
3. idk
4. Imola

I could have mentioned only 2 of the reds are BMW.

1. Rosso Corsa
2. Melbourne
3. Imola
4. Carmine

[attbimmer]

I've officially got a 2wd F81 wagon body with the transmission tunnel work now done. Getting awfully close to bringing the body home and can start moving the drivetrain over. Really looking forward to finally switching my tools from off to on.

[Boznien]

It's getting exciting... I wouldn't even know where to start if I had this project. Massive props to you, sir!

[scotty737]

Originally Posted by attbimmer

I was also comparing the strut bar mount points between the wagon and M3. In order to fit the larger aluminum brace from the M3 there is a rivnut on the outside edges of the body on the M3. In the F31, the hole for it is already drilled, but no rivnut. That is easy to add.



There is additional bracing that goes back from the strut to the base of the A pillar. At that point there is a different type of bolt hole welded in some how. Can't see behind it and doesn't look like that part can be ordered individually. I'll likely cut the M3s out to see what it looks like, but may use a rivnut there as well. That probably isn't as strong though, so will think about it.

I just did a rivnut here. You never see if

[attbimmer]

Originally Posted by scotty737

I just did a rivnut here. You never see if

Even BMW uses a rivnut there so I just ordered one from BMW and will use it there. My issue is on the other spot near the A pillar base. I cut around the top section on the donor car and it is a much more complex structure underneath that is welded into the body. It isn't impossible to remove it and move it over, but would require a lot of cutting and rewelding on the wagon body, so for the moment I will probably pass on that unfortunately. Just not sure it would be worth cutting up the wagon enough to add it properly. I can see how it is very functional though and provide a lot more support as the carbon bar ultimately is anchored into this spot.

[attbimmer]

If you guys have an idea on something that is worthwhile to add to help reinforce without cutting up the body let me know. I may just take a metal plate and weld it on top to at least double the thickness there.

[scotty737]

Originally Posted by attbimmer

If you guys have an idea on something that is worthwhile to add to help reinforce without cutting up the body let me know. I may just take a metal plate and weld it on top to at least double the thickness there.

Originally Posted by attbimmer

Even BMW uses a rivnut there so I just ordered one from BMW and will use it there. My issue is on the other spot near the A pillar base. I cut around the top section on the donor car and it is a much more complex structure underneath that is welded into the body. It isn't impossible to remove it and move it over, but would require a lot of cutting and rewelding on the wagon body, so for the moment I will probably pass on that unfortunately. Just not sure it would be worth cutting up the wagon enough to add it properly. I can see how it is very functional though and provide a lot more support as the carbon bar ultimately is anchored into this spot.

I was talking about the a pillar. I did a riv nut there and it has been fine. I also think this is what everyone has done when doing these conversions. I question the importance of this extra mount as the f87 comp/cs doesn’t even have this extra bracing.

[attbimmer]

The extra front subframe mounts got welded on, so now body welding is all done.




Ended up changing plans a bit with the body. Since everything is about ready for paint now except for the rear bumper we are going to go ahead and just paint everything we can now so that I don't need to take the body back and forth twice. After they are done with paint I'll bring it home and get the rear bumper combined and fitted later on and then will take just the bumper back to them finish it and paint it. They should be able to start painting next week so perhaps the week after some time I'll be able to pick it up.

While waiting for the body, I will probably separate the transmission from the engine so that I can take a look at the clutch and see if it needs to be replaced before everything goes back in the car. Honestly I'm hoping it is ok since the last thing I need is another part to buy, but now is the time if needed. Car had 64k miles and a tune the last 10k miles or so. Other than that will enjoy a little break. I've got enough parts lying around, so don't want to take anything else apart until I can put it right back onto the wagon.

[attbimmer]

I removed the clutch today to see what condition it is in. Doesn't look terrible, but does seem worn. Measures at 7mm. Not sure what min is. The dual mass flywheel also looks fairly worn. I've seen worse, but certainly new would be much less movement.



Here is a video that shows play in the flywheel.

flywheel play

[TouringM3]

My man - you're doing an awesome job. I've gotta plan a road trip down to Cali to link up with ya at some point this Spring / Summer.

[e46IX]

Good stuff, and I appreciate you showing the detail in the bodywork where you're making the cuts.

I'll be doing the same build over here in Canada shortly as well. I have a 2017 F31 330xi here and a 2015 F82 M4 6MT donor. Wish I got my hands on an F80 M3 donor, I have a lot more headache on my side with the body harness aspect and then on top of that pre-lci vs lci differences in electronics/wiring.

[TouringM3]

Originally Posted by e46IX

Good stuff, and I appreciate you showing the detail in the bodywork where you're making the cuts.

I'll be doing the same build over here in Canada shortly as well. I have a 2017 F31 330xi here and a 2015 F82 M4 6MT donor. Wish I got my hands on an F80 M3 donor, I have a lot more headache on my side with the body harness aspect and then on top of that pre-lci vs lci differences in electronics/wiring.

Important heads up here - the M4 flares and rear bumper are vastly different than the M3 (which you'll need to do this right). You'll want to be on the lookout for a wrecking yard with M3 quarter panels and rear bumper.

See here that the rear bumper isn't shared M3 v M4:
https://www.realoem.com/bmw/enUS/par...&q=51128055991