Thread: thought on maf sensors

i had a thought which led me to a question.

quick example: on most intake systems for newer cars, they have a plate built in to the pipe where the maf sensor housing was. and you just screw in your maf sensor on to the plate and eliminate the housing.

now i was wondering, how hard would it be to do this for our cars? because the stock SR maf is kind of restrictive. and to upgrade you have to get an upgraded maf (N60, N62, etc.) and an ecu to run it.

so would it be too difficult to just fab up a plate for it and run the sensor into the intake pipe?

just kinda thought this would be nice to have the free flow without switching mafs, rewiring, sending out ecu's, blah blah blah.

I thought about that one myself, even tried to take appart an E60, but ended up breaking it because it's a little too sensitive, so gotta be careful. Then you need to figure out on how to mount it without it leaking.

well.. the SR sensor is alot easier to disassemble. it's just 2 screws. and as far as making it not leak, i mean tracing it out as a template for mounting, and then adding like 1.5'' sides to it to mount to the piping seems like it should work.

then as far as the seal goes, the actual sensor part of it looks to be about 13-14mm in radius. so if you make a 15mm hole in the plate where the sensor would bolt up to, the rest of the plate could be solid. and then just use either a fine o-ring or gasket paper for the seal.

this is just off the top of my head though. i'm a sucker for wishful thinking.

Looking at a stock DE MAF makes me worry about this idea. I somehow get the feeling that it is designed to get less air flow (it is set off from the main air flow) than the main pipe and just figures if it gets some air, then the engine is getting proportionally more air. If you put it into the main flow path I'd be worried it would read tons more air, and that would signal the computer to put too much fuel in.

it would read more air because it's getting more air.

if you bore out a stock maf, it will get more air and run leaner. not by a huge noticable amount, but it will have an effect on your a/f. but im wondering about my concept vs stock maf on the same car. i would want to tune each setup to see if after a/f adjustments and possible minor timing adjustments (just minor stuff) if the setup without the restrictive housing would actually make more hp. i mean, just by physics and theory, i would have to say yes. and i would also have to believe that it would make for better/more consistant velocity. as opposed to coming in to a 3'' filter, funneling down to a 2'' or 2.25'' maf housing, and back to a 2.5-3'' pipe.

I'm not sure of my theory, but you're not understanding it.
The MAF element is set in the MAF housing with it's own airway separate from the main airway. This airway is off to the side and has a very oddly shaped and seemingly restrictive outlet. All of this conspires to reduce flow around the MAF element. When the engine is getting 100 units of air, it might only be reading 33. Okay, so the ECU sees 33 units of air and adds enough fuel for 100 units of air. Now you are going to go put this element in the main airflow where it will see 100 units of air. It will then tell the ECU it sees 100 units of air, and the ECU will think that the engine is getting 177 units of air. Or 300 units of air, or whatever the factor or multiplier is. It will give fuel according to this. Likely much more fuel than you want/need.

That's me theory anyway.

yea.. i know what you mean.. but that's the whole experimenting thing comes into play. i'm just a curious person i guess. never know

The stock de maf is very touchy. Andreas used to bore the stock mafs and you needed to retune because of it. x 2 on what Ben said. It's gonna throw everything off. It's not even worth your time without the tune correction factor.

It was talked about on the old forum.

maf trick from the people of PR - SR20 Forum

I don't understand why you couldn't tune for the difference. Sure it will read leaner but you can't use something like Calum RT to adjust it?

At the same time I don't see a real advantage either. Seems like a lot of work for very little gain.