Rusty M5...how to restore

[BobM5]

OK...here is my problem. I just picked up a new E28 M5 with plans on doing a proper restoration. Car has a history of life in the snowy northern U.S. The car has significant structural and non-structural rust (ie rockers both sides, lower a columns, firewall, floor pans, trunk floor, rear bumper supports, front core support). I'm not talking surface rust..I'm talking holes. So locally there is a non running schwartz e28 that I can pick up for next to nothing with a rust free unibody. Thinking about buying the unibody and moving everything over to it....doors, hood, trunklid, interior, motor, drivetrain, suspension...everything. I know that I would have to cut out and weld sway brackets, battery box, and the airbox bracket from one to the other. Also, I do all of my own work so time, not expense is the only cost. So 2 questions...anything else that I would need to be aware of (ie differences in bodies) and second...what do I end up with a standard e28 with m5 parts or a rust free M5? My state will let me petition to keep the M5 VIN if I can prove that it is the majority of the car (BTW other than dash and body stickers is the vin stamped in the shell?)...if denied I get a "rebuilder" title and new VIN...my guess is with pictures, the original vin stickers on body panels, etc I will be able to keep vin. Thoughts? Should I just part the car? Any input would be appreciated.

[skip535i]

OK...here is my problem. I just picked up a new E28 M5 with plans on doing a proper restoration. Car has a history of life in the snowy northern U.S. The car has significant structural and non-structural rust (ie rockers both sides, lower a columns, firewall, floor pans, trunk floor, rear bumper supports, front core support). I'm not talking surface rust..I'm talking holes. So locally there is a non running schwartz e28 that I can pick up for next to nothing with a rust free unibody. Thinking about buying the unibody and moving everything over to it....doors, hood, trunklid, interior, motor, drivetrain, suspension...everything. I know that I would have to cut out and weld sway brackets, battery box, and the airbox bracket from one to the other. Also, I do all of my own work so time, not expense is the only cost. So 2 questions...anything else that I would need to be aware of (ie differences in bodies) and second...what do I end up with a standard e28 with m5 parts or a rust free M5? My state will let me petition to keep the M5 VIN if I can prove that it is the majority of the car (BTW other than dash and body stickers is the vin stamped in the shell?)...if denied I get a "rebuilder" title and new VIN...my guess is with pictures, the original vin stickers on body panels, etc I will be able to keep vin. Thoughts? Should I just part the car? Any input would be appreciated.

If you want to do the swap, why tell the state? Just switch everything over and the less they know the better. Sheesh...

[mooseheadm5]

There are VIN tags on practically every removable body panel, under the rear seats (IIRC) and on a couple places hidden by trim. It won't be an M5 again, unfortunately, but it'll be just like one.
I'd be very surprised if any state allowed a VIN swap like this. Where are you located, anyway? You in Alabama where that really nice looking black shell is? If so, buy that car right now.

[Son of a]

There are VIN tags on practically every removable body panel, under the rear seats (IIRC) and on a couple places hidden by trim. It won't be an M5 again, unfortunately, but it'll be just like one.

The first part is 100% true. As for the second part, I disagree. It's an e28 M5, not a 40+ yr. old race-pedigree Ferrari. It will be as much an M5 as any with an S38 in an e28 chassis with all the other M5-unique elements. Hell, if you include all the crap many (if not most) M5 owners upgrade (SLS, SSKs, BBKs, rims, cam gears, exhausts, etc., etc., etc.,) it could turn out better than a "real" M5.

I'd be very surprised if any state allowed a VIN swap like this.

I'm not. To most DMVs this is just an e28 to e28 repair. Getting it registered like that just helps preserve whatever "authenticity" the car might need to still be considered an M5.

To the OP, if you have got the skills and the parts to do it, then do it. Definitely go for that type of informed registration. Silver lining, if you lose your case, you'll be saving a lot on insurance.

[TheE28Ranch]

An arbitrary E28 with an S38 drivetrain does not make it an M5. Sorry, it has to come off the line that way. But a solid clean E28 with an S38 drivetrain is a better platform than an original M5 that is too far gone with rust.

[mooseheadm5]

Not being an actual M5 chassis will kill the resale. You would be building an M5 clone. This is one reason I didn't simply dump all my M5 stuff into a regular E28, even though I had an awesome looking Konstantinrot (I think that is the correct color name) 82 528e ready to go. Instead I found the CarBQ car and parted my old car. There is nothing wrong with your plan at all, but if you ever try to sell the car you are obligated to tell the buyer or you are committing fraud. However, if you are going to swap stuff over, why not chose a car that isn't black for a donor? In Europe, you could get all sorts of colors on an M5. That is what I'd do.

[alpinacsi]

If you were able to get part # 41 00 1 937 969 and transfer all associated parts; what would you have?

[Duke]

Not being an actual M5 chassis will kill the resale.

A "M5" chassis would be a E28 chassis correct?

518
525
528
533
535
M5

All have the "M5" chassis.

[stuartinmn]

Like it or not, the end result would be an M5 clone.

[Duke]

Like it or not, the end result would be an M5 clone.

I don't care either way. My point was, there is no such thing as a "M5" chassis.

[mooseheadm5]

So you could get an Alpine and transfer all the Tiger parts and have a Tiger?

[Duke]

So you could get an Alpine and transfer all the Tiger parts and have a Tiger?

Nope....there are chassis differences (firewall, trans tunnel….etc.) that were done at the Jensen factory. Believe me, it has been tried a lot and the cars are discovered as clones or Algers and worth 1/2 of what a Tiger is.

There are not any chassis differences in the E28 family.

[buzby]

Do it, so what if it is an M5 clone? Especailly if you can get the other E28 for a decent price. Yes, the value will be less than an original M5 but as time goes on more and more original M5's will bite the dust due to accidents, rust, engine failures, parting out, etc so it makes sense to at least save the heart and soul of the original car.
I have the opposite, a totally rust and accident free M5 sitting in my garage with a broken heart and soul. If you ever think of selling the engine......

[mooseheadm5]

There were minor chassis differences, like the front sway bar mounts and the rear battery box. Nothing that couldn't be recreated, same as with a Tiger from an Alpine. It can be done, and people that want to do it can do it right if they are good. The differences might be spotted if you are really really good or poke deeply enough, but all that doesn't matter. What matters is the VIN assigned by the factory (it is stamped on the body in addition to being included on the stickers.) The M5 was put together in a different factory from different parts and hand finished. Because of this is a different car, even though many of the differences are minuscule, like the odd bracket here or there that isn't installed on the other E28s. Does it matter when it comes down to driving it? Not really. I'd take an M5 clone over an M5 with holes in it any day. Does it matter when it comes time to sell? Absolutely, but the condition of the car matters too. There are more than a few really really nice 535s that deserve to command more than the average M5 price wise, but they will never be as rare as an M5 or a tuner E28.
Speaking of which, if you drop all the Alpina parts you can find on a car, is it an Alpina? There are no chassis differences.

[Rich Euro M5]

One difference between the M5 and standard E28s is the amount of front caster. This was accomplished by repositioning the strut towers in the M5 chassis. Another difference is factory cut, rolled, and welded rear fender lips. And one cannot forget the VIN being stamped into sheetmetal in several locations. With the exception of the VINs it would take a knowledgable person identify a well executed M5 clone.

Just my $.02

Rich

[mooseheadm5]

One difference between the M5 and standard E28s is the amount of front caster. This was accomplished by repositioning the strut towers in the M5 chassis.

I did not know that. Thanks!

[M5BB]

Gee Rich where did you get that tidbit of information?
Very interesting can you explain it more please?

How was this accomplished? Wern't all the bodies from the same factory?

[Rich Euro M5]

Gee Rich where did you get that tidbit of information?
Very interesting can you explain it more please?

How was this accomplished? Wern't all the bodies from the same factory?

I stumbled across it somewhere, don't recall exactly where. IIRC, the reason given was to improve stability at Autobahn speeds.

Increasing the caster during body assembly isn't difficult. Look at the strut towers, the upper hat is a separate piece which is welded / bonded to the inner fender. It's my understanding the M5 body shells were produced in batches / blocks on the DIngolfing assembly line and then shipped to the Motorsport assembly facility for final assembly.

Maybe someone else "rcbmw" with more knowledge will chime in.

Rich

[BDK]

If you were able to get part # 41 00 1 937 969 and transfer all associated parts; what would you have?

funny,
some may remember one of those, BNIB if you will, being auctioned off on Ebay.de a few years back...went for $4k...

[wkohler]

Gee Rich where did you get that tidbit of information?
Very interesting can you explain it more please?

How was this accomplished? Wern't all the bodies from the same factory?

I stumbled across it somewhere, don't recall exactly where. IIRC, the reason given was to improve stability at Autobahn speeds.

Increasing the caster during body assembly isn't difficult. Look at the strut towers, the upper hat is a separate piece which is welded / bonded to the inner fender. It's my understanding the M5 body shells were produced in batches / blocks on the DIngolfing assembly line and then shipped to the Motorsport assembly facility for final assembly.

Maybe someone else "rcbmw" with more knowledge will chime in.

Rich

If that was the case, why does the M5 forward structure have the same part number as all other E28s (just asking)?

http://www.realoem.com/bmw/partxref.do? ... showeur=on

[Rich Euro M5]

Gee Rich where did you get that tidbit of information?
Very interesting can you explain it more please?

How was this accomplished? Wern't all the bodies from the same factory?

I stumbled across it somewhere, don't recall exactly where. IIRC, the reason given was to improve stability at Autobahn speeds.

Increasing the caster during body assembly isn't difficult. Look at the strut towers, the upper hat is a separate piece which is welded / bonded to the inner fender. It's my understanding the M5 body shells were produced in batches / blocks on the DIngolfing assembly line and then shipped to the Motorsport assembly facility for final assembly.

Maybe someone else "rcbmw" with more knowledge will chime in.

Rich

If that was the case, why does the M5 forward structure have the same part number as all other E28s (just asking)?

http://www.realoem.com/bmw/partxref.do? ... showeur=on

Why did you pick a PN for Euro cars ? Not a single US/NA version listed.

PNs from the ETK don't tell the full story. The PN could be the same, but what we don't know is how finished were the body shells when they went to Garching. Or what special instructions / jigs were used during assembly when the block of M5 bodies went down the line.

Like I said in my original post, I read it somewhere but I can't remember the source. I suspect it was Richard Nott's website which was a huge technical resource. Too bad the site is dead. It also might have been in one of the dozens of magazine articles that have been written about the M5 since it's introduction. I've been an E28 owner for 16 years and in this time span I've read volumes about the E28 and M5.

Rich

[wkohler]

I got that number from searching for the number Todd posted. I didn't figure it made a difference. If the Autobahn theory was correct, it would more likely be a Euro anyway given that not many US cars would ever see the Autobahn.

I'll never say the ETK is infallible. Just a thought is all.

[Ciskoe]

Hello Im new to this forum and my name is Francisco..

Im currently working at a restoration shop where we specialize mainly on Mustangs and one thing that is mainly important is the VIN on the actual Shell. We have a 68 Shelby that was completely rusted out and simply because the firewall and roof werent they are restoring it. That VIN stamped on the firewall means and shows its a real Shelby and not a clone.

Honestly it just narrows down on how you want to restore it and how original you want to be, do you want show class, garage queen or a great nice DD M5.

Cisko

[Rich Euro M5]

Gee Rich where did you get that tidbit of information?
Very interesting can you explain it more please?

How was this accomplished? Wern't all the bodies from the same factory?

I found the reference and it wasn't more front caster.

The E28 M5 has 12 minutes more positive camber in the rear suspension than a regular E28. This in combination with other suspension differences was to help tame oversteer in wet conditions. Therefore the body shells are the same with the exception of the differences in brackets used to support the oil cooler , coolant bottle, AFM , etc.

Rich

[///BBX]

I remember reading something stating the M5 chassis had additional welding for reinforcement.
Like a racecar would have stich welded seams.
True?

[Rich Euro M5]

I remember reading something stating the M5 chassis had additional welding for reinforcement.
Like a racecar would have stich welded seams.
True?

The only difference I've noticed is the rear fender lips have been cut, rolled, and welded on the M5. The US/NA M5s we're fairly late in the E28 production run and they might have the later reinforced rear trailing arms. I know my '85 Euro M5 has the earlier version trailing arms.

Rich