I was looking over some info on the S38B36, and I found it used the Motronic 1.2 system, while the M30B35 used the Motronic 1.3 system. I figure the two are very similar in terms of pinouts and logic systems, so I would like to know if the MAF from an E34 M5 would be a direct (or semi-direct) replacement for the AFM in the 535.

Anybody know? (DeWitt, MrProject, MBlaster, DarkHelmet, please chime in, since you guys are the most likely to know)

According to RealOEM, the S38 has a MAF, not an AFM:

http://www.realoem.com/bmw/diagrams/h/a/9.png

Oh, wow. Reading comprehension > me. I don't know the answer to your question.....I'm going to blame that last post on the large dose of NyQuill I just took. :)

If you swapped in the entire Motronic DME, sensors, and ignition equipment, then yeah it would work. But at that point, I would suggest going with a standalone ECU. The E34 M5 MAF is a nice $700-900 ticket item.

Swapping in the MAF for the AFM wont work. There are different hardware hookups, parameters, voltages, etc that the MAF works on. You could go with a Split Second piggyback and pop in the MAF in place of the AFM for under $900 or so. I considered this for one of my E28 M5s (with those barn door AFMs) and determined that I dont want a system with no fail-safes on an expensive engine.

If you swapped in the entire Motronic DME, sensors, and ignition equipment, then yeah it would work. But at that point, I would suggest going with a standalone ECU. The E34 M5 MAF is a nice $700-900 ticket item.

Swapping in the MAF for the AFM wont work. There are different hardware hookups, parameters, voltages, etc that the MAF works on. You could go with a Split Second piggyback and pop in the MAF in place of the AFM for under $900 or so. I considered this for one of my E28 M5s (with those barn door AFMs) and determined that I dont want a system with no fail-safes on an expensive engine.

Has anyone actually tried it, though? The Motronic 1.2 should still be an analog system, rather than the digital systems of later (3.0 and up) Motronic systems. Also, since I am fairly sure BMW doesn't like to constantly reinvent the wheel, the pinouts and voltages are probably the same. Since the displacements are very close (~100ccs) the maximum flow rates are about the same, so there shouldn't be a huge discrepancy with the maximum voltage values.

Also, based on a cursory examination of the AFM and MAF drawings, the plugs are the same, as well, so no more funky wiring.

The Split Second is a nice, proven kit that's good for 10rwhp and about 10-15rwtq. I'd just go that route.

The Split Second is a nice, proven kit that's good for 10rwhp and about 10-15rwtq. I'd just go that route.

Yeah, but it is also 1k. I find it decidedly difficult to accept that a D->A converter and a x-fer function are worth more than 700$, since their MAF costs ~300$.

The pinouts are different from the DME as the MAF from the M is a hot wire type and requires a burn off of the wire. As stated the entire DME would need to be exchanged. Most other pinouts remain constant. there is also cost and availability of the MAF to consider I believe the price to be closer to $1000 plus a core charge that varies.

bmwe34.net mentions that Modern Performance makes one for 500ish. But they seem to be devoted exclusively to 4-cylinder American cars. Anyone know anything about this? (or where one might get a MAF for less than the Split Second)