Trent's S54 Rebuild and Sedan Swap

[Slideways]

Alright, still righting some wrongs over here.

- All new Mk60 sensors installed. I now have ABS and DSC again - Hooray!
- Diff fluid swapped for the right stuff. No more diff moaning - Hooray, again. Old fluid looked surprisingly good but must have been made of something not to spec. Picture of E46 diff that came up from the Titanic attached. At least it's not made of carbon fiber as it would have exploded. Everyone knows that tho, right? Too soon?
- Got a pleasant surprise in the mail.
- Tried a new combination for the DMTL codes. Moved Pin 7 of x60011 to Pin 18 of x60004. Fingers crossed...

Question: it appears the "long" press of the DSC button did not bring up the DSC and BRAKE lights. Just the DSC light illuminates. Is that normal? I seem to remember two lights with the long press? Short press brought on the yellow DSC light as per usual.

To come: Chasing a fuel relay shadow code.

Yes, long press should show both unless you add the track mode LED to the cluster.

[heinzboehmer]

Only full on or full off for M3 MK60. If you code in m track mode, short press activates it and long press turns everything off.

[tlow98]

Only full on or full off for M3 MK60. If you code in m track mode, short press activates it and long press turns everything off.

Interesting. I like that! Thanks for the info.

Weird side note: I held the DSC button for a long time while I was trying to get it to do its thing and it triggered a shadow code in the DSC. Something about > 10-second press. Didn't seem to matter, but odd.

[tlow98]

Running well, but of course the CSB has let go.

Driveshafts are cheap as chips used, so I bought one and am rebuilding it.

First step the CSB. Came off pretty easily with a 3 jaw puller.

[tlow98]

When you’re ignoring the actual work you need to do to pass the BAR smog test and you’re just blissfully painting mufflers while swapping drive shafts.

The new/used driveshaft fixed my clunky DS issues as well. The root issue ending up being play in the U-joints. heinzboehmer swappkng this out also reduced the auto solutions noise for me quite a bit. So nice bonus there. Everything underneath looked ‘normal’ with the shifter.

Oh, and something finally showed up - hoorah!

[heinzboehmer]

heinzboehmer swappkng this out also reduced the auto solutions noise for me quite a bit. So nice bonus there. Everything underneath looked ‘normal’ with the shifter.

Oh awesome, is it tolerable now?

[tlow98]

Oh awesome, is it tolerable now?

a few more driving tests need to be done, but it’s better for sure. TBD for ‘tolerable’. I sure hope so. I don’t feel like swapping it all haha

[bmwvsevo]

tlow98, thank you for documenting your build. Helps me a lot with my S54 rebuild that I am starting right now. I know it has been a while since an update but I wanted to check in and see how the motor has been performing?

[tlow98]

Updates :-) In order of most impactful to least impactful.

Tune + Airbox



Installed:
- HP ECU with Bry5on's "mullet" tune fantastic overall - more on that below. Stock CSL tune was rough, to say the least.
- Karbonius matte carbon airbox with their non-flap air intake piece
- Placed the MAP sensor inside the ECU/ABS bin

Impressions with STOCK CSL tune
Quieter than my old Evolve airbox, especially down low in the rev range. Driveability is better than the Alpha tune I had on the Evolve box. Overall, throttle response suffers below 4k RPMS, however, it does scream quite satisfyingly above 4k RPM. It suffers enough in low RPMs that loading the throttle on the highway in 6th is a mostly miserable experience, or climbing a hill in practically any gear below 3K RPM. It bucks and misses and generally is a crap experience. I'm likely more sensitive than most, but it was crappy enough that I found myself grabbing the keys to my MIL's Subaru Outback for short trips around the town. Yep, that bad. Honestly considered selling it and going back to stock as the whole point of this car was to build a daily driver. Daily drivers need good throttle response and resolution low in the rev range.

Impressions with the "MULLET" tune
Power, refinement, and throttle response are all back in spades. I think the highest compliment I can give is that it drives like a normal car again below 3-4k rpm. And above that power feels much stronger. More on power in a minute, but I think the most important thing is that I can drive it like I want and I don't have to drive around the airbox inadequicies. Little things matter.
- The clutch feels like it should at takeoff. Yes, this changed for some reason that I can't explain.
- Rev-matching downshifts is dependable again - what a concept!
- I can climb my driveway at any speed in 1st gear now. Previously it would chug, and buck on my steep driveway
- The engine doesn't ping when when accelerating at low RPM. Hooray, my engine isn't living on the knife edge of some tuner's reduced knock sensors.
- I can start in second gear like a boss, again.

And then there's the big things...
- I can go WOT at practically any RPM, which will pull cleanly. It won't buck and chug and fall apart.
- Power. I did pulls against a stock convertible M3 with the airbox and the mullet tune. Above 4k RPM in third gear through the top of 4th I would pull 5+ car lengths. With the stock CSL tune I would pull barely ahead of the stock car. Not scientific, but the results were repeatable, and the seat of the pants is worlds better. On my favorite and frequently traveled roads I'm faster everywhere and need to watch the wheelspin more closely (I'm running 245s square, remember).

Anyway, worlds better. Super happy to have this tune. I'm happy the car is safer and running better. Hard to beat that combo.

The only area I've found that still feels off is about 2.6k tp 3.3k RPM. It feels a bit 'soft' for lack of a better term. This could be that I'm running stock headers (Bry5on's car has SSV1's and a flap) and no flap. Flap will be installed on my car soon and I'll follow up on that change.

M3 MK60 ABS brain box
- This was maybe the biggest PIA install I've ever done. However, the ABS now talks to the rest of the car and works wonderfully. Nice to have TC back again, and in a much more competent form. Worth the pain, for sure.

New Instrument Cluster
- Old one failed. Was high mileage (211k) and doctor'd by Kassell. Not sure why it failed, but either of the previous could be to blame. Ebay sourced a low mile unit (64k) and moved on. Gauges are much nicer looking with low miles as nothing is faded. Nice to look at!

Engine update
- ~4k miles on the reuild.
- Car seems to be running strong with no issues to speak of. I suspected I was burning oil as I had to add some, but between switching the ECU (CSL has a tighter oil spec reading), multiple short oil changes, and the initial fill that swallowed way more than you might think... I'm just not sure I have good enough data to say. Will keep an eye on it, but it hasn't called for any in 1,500 miles+ so we'll see.
- Hope to check the valves and do another oil change in the next 1k miles.
- Oil leak at the timing chain cover. Yay. I'm a fool for not decking the timing chain cover when I decked the block. Not excited to tackle this. Likely it'll stay leaking for a bit as it's a bear of a job and it's only a small leak.

What's to come
- CSL OE intake flap install. Sitting in a box. Need to be less lazy :-)
- More autcrossing. The maiden voyage autoX was this spring and the car performed flawlessly.
- Would like to install an equal length section 1 dual resonated set of pipes.

Final Note
- The car is NOT raspy, which I love. The airbox + stock headers + E36 M3 exhaust yields a combo that is overall quiet and then, when you want it, all the intake roar you could want. It's civil, but alarming when you want it to be. The key for me is that I can make it loud, but only when I want. Not all the time. Happy for now.

[tlow98]

tlow98, thank you for documenting your build. Helps me a lot with my S54 rebuild that I am starting right now. I know it has been a while since an update but I wanted to check in and see how the motor has been performing?

If I had to redo the rebuild I'd pay more attention to the bore finishing. I think mine is obviously working well, but it's not an area I'd leave to chance. Go with someone like Anri on here who has a lot of first-hand experience with these motors.

[tlow98]

Update.

Thanks to Bry5on for designing a nice exhaust bracket for his setup (SSV1 headers and cats). My car has the stock US header + cat combo, and can use the same bracket except the US section needs a 2.25” clamp vs the 2.5” for the SS larger pipes.

It works. Love it. Car is smoother all over, but especially around idle. Blips are butter smooth. No more jostling and much less bucking. It’s subtle, but when you spend a bit of seat time in these cars it’s definitely noticeable and easy to see why BMW used a similar bracket on the m54 cars.

[tlow98]

Oil change and a steering wheel.

I wouldn’t normally post about an oil change, but since I rebuilt the motor myself there’s sometimes that unspeakable thought in my head that the motor’s about to eat itself. Happy to report that this 4K mile change was clean of any debris. No sparkles, no flakes, just somewhat dirty oil! I’d say it’s certainly fully broken in now. Time for dyno maybe? heinzboehmer what shop did you use for the dyno time? I forget…

In true, semi-beater swap fashion, this car got another hand-me-down from a fraaaaan. Leather wheel! The alcantara ZHP wheel never did it for me. I re-did the leather dye with the colourlock kit. Good kit, would recommend. Of course it didn’t take the deeper gouges out, but it’s respectable looking and feeling now. I’m going to try the full button-less trim for a while. I don’t often use the options.

Also, somehow I snagged the clock spring on the way off with the wheel. If this happens, don’t sweat it, just wind it all the way up and put the cover back on. Now wind it lock to lock without installing the wheel and count the turns. Then turn it to the middle of the range and you’ll be good to go.

[heinzboehmer]

Time for dyno maybe? heinzboehmer what shop did you use for the dyno time? I forget…

Been going to Charlie up at Sonoma: https://www.charliehayesracing.com/dyno

Let me know if you do end up going, I'd be down to join and see what the mullet does on my car.

[maupineda]

What is the cost of the dyno runs?

[heinzboehmer]

What is the cost of the dyno runs?

Been a while, but I think it's around $150 per hour.