VAF to MAF conversion
 

I have the old style VAF meter in my ti. I'm wondering if there is a swap I can do to make it a MAF type system. I was looking at the connectors on the 1994 328i MAF sensor, and the connector on the VAF meter in my car. They're the exact same. Can I just do a direct swap and dump a MAF in my car if the connectors match up and couple together? Or is there some other proceedure that I would have to follow? Or, trial and error, put one in and see if it works? One of my instructors says it might work, it might not, but if it does, there will be a small power gain. And I mean small, like a couple of horses for getting rid of the restriction that is the VAF meter.

I'd give the trial and error a shot, worst thing that happens is the car runs like sh*t and stalls

I'm pretty sure I have a MAF leftover from my swap, shoot me a fair offer and it's yours. BTW, I'm in SoCal if you're in a rush to try this.

Hell yeah, I'll take it! If you're within driving distance of me, I'll just come out, put it in really quick and see if it runs. If it does, I'll be more than happy to take it off your hands.

Anyway, PM me and I'll get you my phone number.

EDIT: I noticed you're in Ventura. Looks like I have an excuse to go on a road trip! You're in the 805, right? My dad works in Fillmore, so it's not that much further than when I go to visit him on the weekends.

To be honest, I'm fairly certain that it's not going to be a simple "plug and play" modification. Reason being is that the two items work off of different principles. The MAF sensor(newer style) has a strip of film that heats up at a perscribed interval. The film is then cooled by the incoming airflow and a measurement is calculated and relayed to the ECU which then controls how long the fuel injectors stay open. The older style used on '95 318ti's is called an Air Flow Meter(AFM). It measures air by volume rather than flow. Basically the air passes through a trap door where it is metered and a signal is sent to the ECU. I'd start by getting a bentley manual and reading the pinout for the Mass Air Flow Sensor and compare it to the pinout of the Air Flow Meter. I'm thinking the AFM won't have the same type of heating element that the MAF does. You'll more than likely need to tackle a software issue and very likely rewire a corresponding connector for the MAF.

I still need to check and see if I still have my M44 MAF. IIRC, it's still attached to my old airbox in my trunk. Anyway, I'll PM you my phone number and you're more than welcome to swing by or I can just as easily mail it to ya. I'm 100% positive that it's in perfect working order. My car ran awesome and passed emissions with flying colors just prior to yanking the M44 out for my swap.

I just re-read your first post and the sensor you were looking at was from a 6cyl. There's no such thing as a '94 328i, as they didn't come out until '96 when BMW switched from the OBDI 2.5L M50(325i) to the OBDII 2.8L M52(328i). Either way, the 318ti's OBDII 1.9L M44 MAF sensor will be slightly smaller in diameter than the 6cyl MAF.

LMK if you're still interested, I'll post pictures of the connector on the MAF tomorrow. I no longer have the M44 engine harness, so if the plug is different than the one on your M42 harness, you'll need to source a pigtail.

Here's a good deal, this guy is asking for less than I would and it's a 6cyl MAF:
http://cgi.ebay.com/BMW-96-328is-e36...d=p3286.c0.m14

I'm getting a $440 check next week, I should be able to make a fair offer by then. Also, I have no credit card, so I can't make an Ebay account. I was wondering, if this idea actually works, would you like to take my VAF meter and try to sell it? At service shops, they usually go for over $150. I'll check Harout's to see what they would sell a VAF type sensor for.

It won't work. They work off different outputs. You might be able to get the connectors to work but the ECU will just throw up at the data. I don't even know why you would want to do this on a stock ti. You're much better off spending that money on a chip which will give you up to ~8 hp and a few hp/tq at peak.

It won't work by simply plugging in a the newer style MAF and going on about your business. You need to use a signal converter to properly calibrate the signal from the new sensor to what your DME is expecting to see. To do this right you also need an AFR/wideband O2 sensor.

Splitsecond sells their ARC/MAF update unit, and people have run that with success. I've never seen a before/after dyno chart to know if they saw any power gains. I would expect it isn't much as you don't peg(5 volts) the barn door style sensor at full throttle.

Ok, so it's not "Plug and Play" like I hoped it would be. But still, is this a conversion that is worth doing, or should I keep my behemoth of an air meter? I was thinking of going with a chip since there is a Dinan dealership within 10 miles of me, would the Dinan shop carry the items I need to do the conversion should I decide to do it?

It's not worth doing. The M44 does not even get close to requiring the full airflow of the AFM. Unless you supercharge it, or turbocharge it, you won't need to do it. They use the same size AFM on the e34 535i which has much more airflow.

Instead, go get a chip from Dinan or some other tuner (ebay has a lot of cheap clones too).

I don't trust Ebay anymore. I've gotten too many bulls--t parts from there. I think I'll stick with Dinan products for now.