540i HFM on M50 engine

[lukasbmw]

Just got a decent deal on a 540i HFM and it is heading my way. I know it will connect right into the stock plug and my current cone air filter is large enough to fit over the 3.5" HFM, but my throttle body tube may be too small. Anyone know where I can get an adaptor?

I tried the bulb and beer can on another project and it did not work so well.

Now other then cutting off my cat or adding a big bore throttlebody, my M50 has pretty much every bolt on mod possible.

For those that don't know:
M50 2.5 Vanos
E36 M3 Cams
LukasBMW intake and shield (HUGE cone)
Fuel Pressure Regulator
Tublar exhaust manifolds
Supersprint exhaust
JC cam chip

I'm currently running a little rich so I don't think the extra air coming in will screw up my A/F ratios. We will see if the 540i HFM does anything for a modded 2.5 Vanos. The 3.0 and 3.2 guys love this mod.

[NickP]

You are correct that you'll either require an adaptor or the light bulb trick. But you'll also need custom programming - the mappings are way different than your stock MAF.

[Rich V]

Usually when people do the 3.5" AFM on the E36 cars it is combined with larger injectors and custom software. The big issue with why people do not do it on M50s is that such custom software does not exist, as NickP said.

Have you done any dyno runs yet? I know the M50 with S50 cams can be a pretty hot motor. I would be very interested in before/after runs to see what kind of difference it made.

Keep us posted and good luck.

Rich

[Ryan Stewart]

You are going to need software from what I have been told. The guys from the S50 group say it wont even run without software because its a HFM versus MAF so it meters differently.

I have this, a filter, and 21.5# injectors for my 3.0. Turner sells an adaptor for like $60 but some people have said a brand new boot and a heat gun = easy streching. The old boot would probably just crack. I am going to give that a shot because the turner adapter has a pretty sharp stepdown that would seem to negate any gains from the HFM. Hopefully soon I can get the BBTB too.

[aaron_silva]

I have heard the the 2.5 wont show much gains because it doesnt flow as much as the 3.0.

Aaron