Obd i m54?

[e30guydownunder]

Anyone done it before?

I whizzed two of the inlet studs out of my M54 and plonked on the M50 manifold I had lying around.



I also sat the M50NV Rocker Cover I have on there. It hit the Vanos unit obviously but with the vanos unit removed and the NV blanking plate off the front of the M50 the cover should bolt right up. I don't see why you couldn't use an M50 Vanos cover and Single Vanos unit.

Then the last thing to check out is the crank sensor. I could have my mate alter the coding in the 413 to correct the base angle and use the M54 sensor, but I also think the M50 Timing case will bolt up. Then I can use the M50 crank pulley and sensor.

So my plan is to swap all my M50 gear on there and run the 413 ecu I have. Which will basically give me an Alloy M50B30....why has nobody tried this before?

Obviously I will lose out on the Vanos and DISA benefits but this seems like alot less head aches for 80% (maybe 90%) of the power.

[nando]

DISA is one reason I can think of not to do this. double vanos is one of the biggest reasons to do an M54.

surely somebody has hacked the stock DME by now?

[DesertBMW]

surely somebody has hacked the stock DME by now?

I am in the process of doing it. I will post wiring information once I complete the project.

[e30guydownunder]

Speaking of DISA. The M50 inlet manifold is 4kg's lighter than M54 manifold! I will say for the daily driver an OBD II swap does make sense, it's worth the effort. I will be using the engine in an e36 compact for rally use so I less worried about drive ability and flat torque / power curves below 3000rpm, so the simplicity of going OBD I makes sense for me, more importantly the weight savings of the alloy block.

[hoveringuy]

I would say that the M50 manifold is absolutely the wrong manifold to use on the M54 for several reasons.

1) you're giving up DISA which gives huge gains in torque over the M50 manifold
2) M54 manifold flows to the capacity of the head. The restriction is in the head, not in the manifold.
3) you can't use the idle circuit passages in the M54 head.
4) M50 head doesn't make OBD-1 any easier.

I ran an M54 OBD-1 with the original manifold and retained DISA. It can be done, but the problem for any OBD-1 application on a non-standard motor is tuning.