Info on 540i MAF / Euro HFM

[m3_eater]

Hi all,

I've done a bunch of searches both here and other locations, and not found what I'm looking for. Basically, I need to know which MAF/HFM is best suited to my purpose.

I'm running an M52B28, OBD1 (M50 manifold, etc) with S52 cams and 21.5lb injectors. I plan to have Chuck Stickley provide the tune, once I have a 3.5" MAF installed. I've been told that I need a 1994-1996 MAF from a 540i, 740i or 840i. Thing is, searches for these parts all seem to turn up different parts from model to model and year to year. Are they really different, or will just any one work?

Also, is there really any additional benefit from running the Euro 3.5" HFM instead? It looks like any additional tuning points provided by the Euro unit might be redundant for a simple ODB1 application like mine.

Thanks in advance!

[318isbmw]

Mine's out of a 740 and it works ok even w/o a tune. Odviously would work better w/ but it runs ok, doesn't die or anything w/o one. I'll look for part numbers this weekend for it.

[tjcm3]

I'm running the 540 HFM with Shrick Cams, 24# Injectors...etc. When I asked Turner Motorsports about the Euro 3.5 vs. the 540 with regard to the JC chip they said "same thing". So, it sounds like though they're different PNs, they're close enough that they don't require different tuning.

[chuck90m3]

As we told you when you picked M4tts car up you will need a HFM from a 5,7,8/40 from 92 to 96. Basically what you want to look for is a 3.5" meter with the round plug/connector. The late model meters have a square plug/connector o0n the sensor and will not connect to your harness.

Chuck

[chuck90m3]

I'm running the 540 HFM with Shrick Cams, 24# Injectors...etc. When I asked Turner Motorsports about the Euro 3.5 vs. the 540 with regard to the JC chip they said "same thing". So, it sounds like though they're different PNs, they're close enough that they don't require different tuning.

The part numbers are different because of how the housing mounts to the airbox on the each individual car

[Mossman]

you can buy brand new land rover/range rover maf's for like $100 by the way. Obviously you need one from whatever years use the m60 or m62, I think 2002 or 2003 rings a bell. I think it has a square connector though, might be worth the trouble though since used bmw ones go for as much as new rover ones.

[chuck90m3]

The Rovers use late model BMW V8 and use late model meters that will not plug into the OBD1 M/S50 engine harness. Again you will need the early model meter

[m3_eater]

Thanks, Chuck! I just had to be sure before jumping, because there are a ton of used ones out there.

[Teaguer]

Theres a bunch of threads on Bf.c about this subject .

Also there seems to be a VW HFM that is interchangable with the 540/740 units and they are alos much cheaper new/rebuilt like the Rover units .
Theres another thread on Bf.c with part numbers and guys who have used them .

[1990m3]

I use the 540HFM I got from a local wrecked car for cheap. Works fine with my conforti chip

[sanya]

Theres a bunch of threads on Bf.c about this subject .

Also there seems to be a VW HFM that is interchangable with the 540/740 units and they are alos much cheaper new/rebuilt like the Rover units .
Theres another thread on Bf.c with part numbers and guys who have used them .

any info on which vw hfm?

i assume for obd2 cars, the 3.5 hfm has to be obd2 as well?

[WillisE30]

any info on which vw hfm?

i assume for obd2 cars, the 3.5 hfm has to be obd2 as well?

Correct.

[matt]

Correct.

Incorrect.

The 540i/euro HFM is not compatible with OBDII. You need a porsche MAF and you need to wire it in a specific way... hence the TMS MAF harness that goes with conforti OBDII intakes.

[WillisE30]

Incorrect.

The 540i/euro HFM is not compatible with OBDII. You need a porsche MAF and you need to wire it in a specific way... hence the TMS MAF harness that goes with conforti OBDII intakes.

Interesting, I was under the impression that the OBDII MAFs could be switched around. Never stop learning.:neutral:

[Teaguer]

part#'s for VW and Rover HFM

This is the Bf.c thread that lists part numbers for the VW and Rover units :

http://forums.bimmerforums.com/forum/showthread.php?t=916617&highlight=vw+hfm