E39 N54 "535i" Project

[exextatic 96]

It has been a few years since my last project (E46 M3 Sedan), and while I'd initially purchased my E39 as a reliable daily driver (specifically not to be modified), I needed something to do a bit of a resto-mod on. An N54 is pretty similar to an M54 though, right? 😁

The subject in question is a 2002 E39 530i touring, purchased in 2018 from a fellow Bimmersport member.
Since purchase, I've put around 30,000km on the clock, performed a full suspension refresh (all bushes, bearing, shocks, struts, air springs) and manual conversion.
Unfortunately the vehicle was purchased with some clearcoat issues, which have only gotten worse.

As this vehicle is still a daily driver, I've also picked up a 2003 520i insurance write-off to use for development / mockup - the pictures below will be of this car.

For a donor, a 2008 E82 135i insurance write-off was used.
Unfortunately, this vehicle was fitted with an automatic transmission, something I'm not interested in for this project so a GS6-53BZ was sourced from the UK and imported.

The underlying theme for this project is "if BMW were to have made it" - I'll be trying to keep everything looking as factory as possible, so no aftermarket BOVs or pod filters. 😀
This theme also flows through to the electrical architecture of the vehicle, I'll be keeping the factory E8x modules (thankfully the donor vehicle came with an MSD81) and aiming for full integration with the E39 instrument cluster via a custom CAN translator of my own design.
The vehicle will have fully-functional A/C, DSC and cruise control. The translator I've developed has been proven in the manual HellBM 135d.

The first step with the mockup car was stripping out everything not needed:

Initial test fitting was performed with a spare N52 parts motor with a GS6-53BZ bolted up:

 

With it generally looking good, an N54 parts motor was made available and put in instead, allowing test fitting of turbos, etc.
Looking doable on the exhaust side:

Going to need to do something about the rear turbo's coolant line:

Enough sump clearance:

 

Tons of room on the intake side:

Some shims underneath to get it all lined up:
 

Sway bar at full droop, clears ok:

Just need to get an engine mount to join A to B and we'll be done in no time 😉

Bolted up a few more parts, still clearing ok:

Starting to work on some mockup engine mount arms so that we can remove the shims, these will only be temporary:

Looking pretty tight on the exhaust side:

Onto some temporary gearbox mounts:

With the temporary mounts made I could then start designing some more final mounts.
A 3D print of the design for testing fitment:

Same again for the gearbox:

 

The exhaust-side mount ended up being rather tricky, requiring many iterations:

 

Final design of the exhaust-side mount:

While that was going on, I took a look at fitting the oil cooler - a factory item on E39 540i's built for the Gulf region:

 

For fueling, I'm wanting to use an E82 135i pump in the E39 holder.
The fuel lines will be the factory-fitted E39 M5 lines, filter and 5 bar fuel pressure regulator.
Unfortunately, the E82 fuel filter sock won't suit in an E39, so a mockup adapter was 3D printed (in PLA, this will be printed properly in carbon fiber reinforced nylon).

Another item to tackle is the coolant radiator, condenser, intercooler and power steering radiator pack.
Initially I'd planned on using an E60 535i radiator but found the dimensions won't work in an E39.
The E82 pack seemed like the best choice, here attached with some temporary mounts (again, will be 3d printed properly in carbon fiber reinforced nylon):

4

Picked up a 540i rear diff and half shafts, it should handle things a little better than the 530i items:

Started mocking up a top cover panel for the radiator:

The intake-side engine mount arm machined in T6061-T6 arrived:

 

Fits perfectly:

 

With the N54 having the A/C compressor on the opposite side of the motor (compared to M54), we started working on custom A/C hardlines.
This one will run from the E39 bulkhead, around the back of the motor to the intake side, and will have a flexible section running under the manifold area to the compressor:

I'm also working on some mounting brackets for it:

 

The next items are sorting out the coolant / power steering / oil line situation which is underway currently.
Unfortunately, the supplier sent the wrong size hardline which has caused a bit of a delay on this aspect.

Another item we're working on is relocating the DSC module to behind the headlight - the E39 units often get baked in the factory location, leading to failure and other weird issues.
The DSC module to be used is a DSC8+ module from a facelift E60 rather than the (unreliable, relatively expensive) DSC5.7 factory-fitted in the E39.

 

 

Edited April 22 by exextatic

[Neil McCauley 249]

Absolutely insane attention to detail. Following closely!