E39 N54 "535i" Project

[exextatic 131]

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 397]

Absolutely insane attention to detail. Following closely!

[exextatic 131]

Time for another update 😊

Some progress has been made on fabricating coolant lines.
The current intention is to use an E39 diesel coolant reservoir mounted on the intake side of the engine bay, freeing up room on the exhaust side for the DSC module and vacuum reservoirs.

Two aluminium pipes run atop the intake side chassis rail, one for the coolant reservoir to the heater core and thermostat, and another from the radiator to the heater control valve.

The next step is to fabricate a hard line to connect these up to the thermostat.

 

In other news, the final exhaust-side engine mount arm has arrived from manufacturing.
Test fitting looks good, with only a small shim required on top of the engine mount to raise the mount up slightly, due to there being more compression in the engine mount than anticipated.

 

 

 

 

With that in place, the gearbox mount design was finalised, propshaft angles were checked and the design sent off to be manufactured.

 

[Cement 891]

Missed the original posting of this project, some nice work going in there 👍 Looking forward to seeing more progress on it.

I've done some work with the CAN integration side of things on my E46 project, sounds like you already have a solution in mind but let me know or take a look at my thread if I can be of any help. There are bits and pieces scattered about my thread, bit of a starting point here: https://bimmersport.co.nz/topic/64728-blue-chunder-e46-318ci-vq37vhr-swap-other-stuff/page/6/ and Arduino code here if thats where you're heading https://github.com/david-morton/BMW_E46_Gauge_Cluster_Control ... hopefully it's a bit easier sticking with the BMW ecosystem.

 

[exextatic 131]

On 5/19/2024 at 8:26 PM, Cement said:

Missed the original posting of this project, some nice work going in there 👍 Looking forward to seeing more progress on it.

I've done some work with the CAN integration side of things on my E46 project, sounds like you already have a solution in mind but let me know or take a look at my thread if I can be of any help. There are bits and pieces scattered about my thread, bit of a starting point here: https://bimmersport.co.nz/topic/64728-blue-chunder-e46-318ci-vq37vhr-swap-other-stuff/page/6/ and Arduino code here if thats where you're heading https://github.com/david-morton/BMW_E46_Gauge_Cluster_Control ... hopefully it's a bit easier sticking with the BMW ecosystem.

 

Thanks David, yeah I've got a homegrown four channel CAN bus translator based on a PIC32MK that I'll be using at the core of this project.

I've been extremely slack with keeping this thread up to date, so time for another update.
Since the last post, the gearbox crossmember has been finished.

 

And fitted to the test chassis, alongside the modified propshaft (135i gearbox flange, retubed, E39 540i from CSB backwards):

 

Onto the next job, creating a custom coolant hardline between the coolant reservoir and electronic thermostat (still needs some brackets):

 

 

While on a roll with bending up hardlines, an oil supply hardline was fabricated as I didn't want to have -AN fittings visible off of the oil thermostat.
For this I also machined an adapter fitting for the oil thermostat.

 

The coolant and air conditioning hardlines I had been working on previously were also finish welded:

 

 

Next up was making the N54 engine loom use the E39 e-box grommet:

 

And the shift linkages were modified:

(Not quite sure where the selector rod photos went unfortunately)

 

Propshaft had a fresh CSB and CV joint installed:

 

I'd also performed the typical maintenance on the N54 I'm going to be using, namely replacing all of the gaskets I can easily access (valve cover, sump, VANOS solenoids, etc) and injector decoupling elements.
New spark plugs and coil packs (standard N54 items for now) will also be used.

 

Looking nice and clean in there.

Nice and clean down under too.

 

 

The next major hurdle was fabricating exhaust downpipes; there's not a lot of room to work with unfortunately.

The vehicle will need to keep the catalytic converters for passing emmissions testing during LVVTA certification, so those were extracted from a factory downpipe set.

 

To complete the factory-like look, some small brackets were designed and 3d printed:

 

And laser-cut and machine folded:

 

Welded on and oxygen sensors added:

I'm extremely happy with how these downpipes turned out; they're currently off being ceramic coated (in an effort to keep under-bonnet temperatures down).

 

A few months have also been spent working on electrical and electronics, starting off with a jump-start terminal.
The E39s all use engine-mounted jump-start terminals, while the N54 never came with an engine-mounted jump-start terminal - all usages of the N54 have them mounted on the chassis.
For this, I designed and 3d-printed a jump-start terminal that will attach to the intake manifold:

 

And finally printed out of PA-CF:

 

Mounted and wired in the fuel pump (EPKM) module:

 

Designed a replacement case for the Comfort Access module, allowing it to attach to the same bracket as the factory E39 PDC module:

 

 

Created an adapter loom for between the E39 X6001 and E9x X6011 / X6021 engine connectors:

The wiring is still ongoing at this stage - chipping away at it slowly.

[exextatic 131]

Another problem needing solving with this conversion is oil level measurement - the N54 never came with a physical dipstick, relying instead on checking the oil level via the oil level sensor. While it is possible to use a scan tool to measure the oil level, I'd prefer to have a quick and easy way of doing this on the go, leading me down the next rabbit hole - designing an in-cluster display to show the oil level (and any other interesting information, such as exact vehicle speed, oil/coolant temperature, etc).

The design is based on an off-the-shelf SPI display, paired with a custom (own design) circuit board using a PIC32MK with a single CAN channel:

3D print a housing for the screen out of ABS (don't worry, this cluster isn't the actual cluster I'll be using in the vehicle, just a testing one):

Test fitting and adjusting positioning with the cluster face loosely fitted:

[Jacko 2158]

Very f**ken impressive! 

[Eagle 1670]

10 hours ago, exextatic said:

the N54 never came with a physical dipstick, relying instead on checking the oil level via the oil level sensor.

I thought the sentence is was going to be you adding one. I give credit to Japanese for not following this stupid euro trend.

Does the BMW DME contain the actual litre reading in its data?

[exextatic 131]

14 hours ago, Eagle said:

I thought the sentence is was going to be you adding one. I give credit to Japanese for not following this stupid euro trend.

Does the BMW DME contain the actual litre reading in its data?

It was contemplated but would be less "oe-like" - either having to modify the sump, or using parts from the BMW Motorsport catalogue that replace the oil level sensor, which then has a flow-on effect on the DME. Adding the screen was more in line with modern BMW and opens up additional opportunities.

The DME does have the oil height in millimetres, which can be correlated to the oil level in litres. This isn't sent out over CAN, however - a simplified oil level overview is sent (and typically consumed by the instrument cluster in a factory vehicle).