M54. Let the foolishness begin.

[hoveringuy]

Would you provide the vanos/software help?

Yep, I have VANOS boards and Hall conversion circuits ready to go. Still working on the tune... it's 95% good and only hiccups in a few weird situations.

[jrdeamicis]

Today marks the one year anniversary of installation and first start of the M54. It's a Holiday in my house and the kids will have ice cream with sprinkles tonight.

How's the motor been over the last year?

Kinda boring, actually.

Reliable.. boring.
Smooth.. boring.
Quiet.... boring.

Never fails to start, doesn't leak a drop. Boring!

Boring is good.

It still has tons of power and even more torque but it seems like I got used to the power so quickly. I already need something bigger and better for my next fix. S54??

I'm still learning a lot about the motor and working on the tune with TRM. It hasn't been as easy as just tweaking an S50 tune, the V/E profile just seems much different.

The VANOS control circuit and Hall to VR circuits have both been dead-nuts reliable. I've steadily made software revisions to the VANOS board and it now works completely invisibly.

The aluminum up front has been great, too.

I would do this swap again and I recommend it for anyone that finds an M54b30 in good condition.

Its great to see how well its working for you.

I would love to see it in person one day.

[MR 325]

Glad to it's still running great. Always nice to see you keep making more improvements in the tune, and more power!

[hoveringuy]

IAT sensor follies

Stuff like this shouldn't take me so long to figure out.

The motor has been running pretty good but there's been that constant *something* that I just couldn't put my finger on. I thought it was a tune issue but it just wasn't making sense.

The symptoms were that the car would run rich when the ECU was first adapting, but after it adapted it would tend to run lean before the O2 sensor went closed-loop. After it went closed-loop it ran fine. If I stopped at a store on the way home it wouldn't accelerate well when I first left the store, but a minute later it was back to normal.

Everything on the motor that relates to OBD1 has come from an M50 EXCEPT the IAT sensor. It snaps into a plastic fitting on the intake manifold and I figured it had similar values as the M50. It even has the same plug. I never bothered to check.

I finally got an M50 IAT and compared the two....they are substantially different. So far it has changed the driving characteristics quite a bit. I won't call the battle won but it's much, much closer.

The lesson is that the IAT has a huge influence on how the ECU programs fuel (and don't assume anything)

[BMWsteve]

Hi i'm new on here and have been fascinated by your hard work and determination to build your m54b30. I have a 325i turbo which i am now bored with so i have sourced a m54b30 with a full engine loom. I am pretty good with engine work but not too sure about the wiring. Is there any chance you could help me here or do you have a wiring diagram? I have read through all your posts here and have been unable to find one. Thanks i would be really gratefull.

[Court M3]

Good Lord got to drive this car today and am seriously still grinning from the amount of smooth power and torque delivery(and I was only at half throttle since it was wet out).

Throughly convinced this swap is worth it! Thanks again Steve for the pleasure.

[mutty]

Yep, I have VANOS boards and Hall conversion circuits ready to go. Still working on the tune... it's 95% good and only hiccups in a few weird situations.

Sent you a PM/paypal.

[hoveringuy]

This is kinda cool... I've been working with TRM to get the tune for the OBD1 M54 and I've learned a lot about datalogging and a little bit more about how the 413 works.

I never understood why the ECU needed to have maps if it had a MAF to tell it how much air mass was being consumed. I've learned that the MAF reading is one-half step behind what's actually happening in the engine and a good map is critical for crisp response. Also, an improper map leads to all kinds of small issues when the engine isn't running in closed-loop.

So, attached are two screen shots of an earlier log from where I was having some leaning issues and a later log after TRM corrected it.

These were taken after the ECU was reset and the O2 sensor unplugged. It is raw response from the ECU before adaptation corrections. The load numbers don't correspond to anything in particular.

The first one shows generally leaner fuel with load and also a lean hump around the 150 load line.


The corrected tune shows slightly richer with load, but most importantly, it's flatter. This one runs great!

On both of these maps the A/F was always at around 14.7 because of the short-term trim. The difference is in how it got there.

[hoveringuy]

I also logged my MAF signal with the DISA valve open vs closed. It shows that the DISA adds up to around 9% to the flow centered around 3500rpm. I switch the DISA valve at 3900 rpm to have good low speed and high speed flow. The DISA and the additional VANOS advance is what gives the M54 better low rpm torque.

The N52 has a 3 stage intake that has low, medium, and high speed configurations.

[mutty]

Holy smokes! What kind of mpg you get from that? Should be way better than any factory bmw.

[ZiMMie]

Hmmm, I'm curious why they ran #6 like that...

these header were design to be used in both LHD and RHD. the #6 runner was made like that to clear rhd steering shaft and to also maintain an equal length like the rest.

[dirtysix]

This is a top thread.
Congrates on figuring this shit out.

[Pzary3233]

This thread just made me want to go buy an M54...

AWESOME thread!!!

[SoEm0]

I am for sure interested in this thread. My buddy has a 330i that I am always working on it seems, but he is starting his search for a s54 swap... which means I will have his block sitting in my shop soon (possession is 9/10ths of the law right :) ) Anyways is there a certain pin out I should be looking for? I might as well start piecing together the stuff I will need for this now.

[hoveringuy]

another dyno day

It's fairly trivial finding the optimum VANOS switching point on a motor where you only have 2 choices "on" and "off". The problem with having the variable VANOS is that finding the best point to have the cams at all times is a little more difficult.

So, I loaded about 10 different cam advance profiles into my VANOS controller and went to the dyno. For the most part, the motor is tolerant of changes in the intake advance profile but it has definite sweet spots.

More intake advance results in more dynamic compression at lower rpms, retarding it takes advantage of the ram effect at higher rpms. Where to strike the balance at mid rpms?

On to the graph...



I fattened up my low rpm torque since last year and made some slight improvements on the top end. TRM has been working hard on deciphering my data for this and the results show.

So, I have 211 SAE whp out of a stock 3.0 litre M54 and a fat torque curve. I think that's about the best I can do on a STOCK motor without hardware mods. ZHP cams, Shrick cams, or even ebay headers would probably yield another 10-20 hp. Plus, if you consider that "power equals weight", the 50 lb aluminum advantage gives you a 5hp "gimme".

Most importantly, this motor is a sweet daily driver. Pulls strong from everywhere and I don't need to wait for it to get on the cam to make power.

Here's what all the runs together look like. Biggest impact was near 4000 rpm where DISA switches. Wrong cam position kills power there!

It's also interesting to see power jump at 2750 rpm where DISA is turned on. I have since moved that point to the left.