Restomod BMW E23 7 Series

[Moulie1977]

Hey

I am new to this forum so this is my first post.

I used to own a BMW E28 528 some time ago which my father bought new and handed down. Sadly the car was rear ended and was written off when my sister borrowed the car.

I am purchasing an 1985 BMW E23 732 which had the engine swapped out for a 735 engine.

The car needs a bit of work so planning to go a derelict style restomod. The body is not perfect but paint is pretty good considering the age and I am thinking of adding a pfeba body kit. As the car will be parked on the street (inner city Sydney) I will match the body kit as best as I can color wise and just happy to leave the minor imperfections so I am not too fussed should further 'character' added.

I am thinking of buying a E60 5 series 545i or F10 5 series 550i as a donor car and swapping in the engine and transmission. There is a place in Sydney www.brintechcustoms.com.au who specialise in this kind of thing and while I haven't engaged them as yet figured I would put it out to this forum to get some feedback to see if anyone has done anything like this.

I know there was a e23 745 which was turboed and which is why I would ideally like to go with the F10 5 series 550i which has the 4.4 litre V8 twin turbo.

Evolve-Technik offer chip tuning and down pipes which take stock engine performance from 299kw/600Nm to 389kw/745Nm.

Again I know this is a BIG power increase but like the idea of creating my version of a E23 M745Nm with 4.4 litre V8 twin turbo with with SERIOUS power.

I am buying the E23 for about $20k AUD and expecting to put in another $80-$100k to update the engine, trans, suspension, brakes, body kit and interior.

This is my first build and have a decent budget and hoping for a derelict style restomod sleeper as a fun casual daily driver with some go.

Has anyone done something similar or have any feedback?

Keen to hear any thoughts even if it will be this won't work!

[kojo96]

Wow, that's a ton of money (US or AU) to pump into an e23 that isn't a unique or known tuner car.

If you're doing it for the "love of the car", can afford it and aren't concerned about recovering your money if you ever sell, I say go for it.

If though, you're thinking about selling it at some point and getting close to even, that'll never, ever happen.

Start a thread on whatever you decide to do, we don't see many e23 builds here anymore.

[RobertRO]

I am thinking of buying a E60 5 series 545i or F10 5 series 550i as a donor car and swapping in the engine and transmission. [...] I would ideally like to go with the F10 5 series 550i which has the 4.4 litre V8 twin turbo.

You need to carefully assess the condition and reliability of these engines. Instead of a N62B44 sourced from an E60 545i, you're much better off with a N62B48TU engine from an E60 550i / E63 650i / E65 750i / E70 X5 4.8i.
While the N62 was far from stellar reliability-wise, its successor N63 was much worse. Stay away from any N63 pre-first technical update (N63 non-TU). Actually, an N63 became a decently reliable engine only after the second technical update (N63TU2). Note that there was also a third update - guess why...

As a side note, the E23 platform is a very old design. Unless you really really fell for its shape, you may want to also consider the E32. The E32 750i came with a V12 engine, therefore it may have more engine bay space than the E23. And that's something that you are going to desperately need, for a modern 90 deg. V8 with huge cylinder heads. The E32 was a significant technological step forward, versus the E23. Bonus, you get an aerodynamic drag coefficient of 0.32, which is not too shy even for today.

[Moulie1977]

Wow, that's a ton of money (US or AU) to pump into an e23 that isn't a unique or known tuner car.

If you're doing it for the "love of the car", can afford it and aren't concerned about recovering your money if you ever sell, I say go for it.

If though, you're thinking about selling it at some point and getting close to even, that'll never, ever happen.

Start a thread on whatever you decide to do, we don't see many e23 builds here anymore.

Hey kojo96,

Yeah just the love of the car. No real plans on selling it. Money is in Australian dollars. I just want a unique restomod sleeper and really like this model. I completely understand that I will never get the money back from the car. Never been in a position to just give myself a goft when it has always been family first so just doing this for me.

[Moulie1977]

I am thinking of buying a E60 5 series 545i or F10 5 series 550i as a donor car and swapping in the engine and transmission. [...] I would ideally like to go with the F10 5 series 550i which has the 4.4 litre V8 twin turbo.

You need to carefully assess the condition and reliability of these engines. Instead of a N62B44 sourced from an E60 545i, you're much better off with a N62B48TU engine from an E60 550i / E63 650i / E65 750i / E70 X5 4.8i.
While the N62 was far from stellar reliability-wise, its successor N63 was much worse. Stay away from any N63 pre-first technical update (N63 non-TU). Actually, an N63 became a decently reliable engine only after the second technical update (N63TU2). Note that there was also a third update - guess why...

As a side note, the E23 platform is a very old design. Unless you really really fell for its shape, you may want to also consider the E32. The E32 750i came with a V12 engine, therefore it may have more engine bay space than the E23. And that's something that you are going to desperately need, for a modern 90 deg. V8 with huge cylinder heads. The E32 was a significant technological step forward, versus the E23. Bonus, you get an aerodynamic drag coefficient of 0.32, which is not too shy even for today.

Hey RobertRO,

This is great information so thank you.

As mentioned I haven't yet engaged Brintech other than a brief email but hopefully as B<W experts they will guide me on engine relibaility choice too. Ultimately I just love the old shark nose Bimmers and the E32 while probably streets ahead tech and performance wise just does not do it for me.

As for space they these Brintech guys did a BMW M3 E46 S85 V10 Swap (https://www.brintechcustoms.com.au/m3e46s85v10 ) so I figure they should be able to shoehorn a V8 into an old E23 7 series or tell me it isn't going to happen.

My preference would be to restomod an e28 and drop a E90/92/93 M3 engine into it in the event that the E23 can't be done. Wait and see and will keep you posted once tis project is underway.

[stuartinmn]

Look for board member Kenny Blankenship - I believe he has (or had) a modified e23. He may be able to give you some tips.