Author Topic: MAF Converter...99% READY TO ROLL! (Read 21788 times)

Damoj · « **Reply #75 on:** January 04, 2007, 09:37:05 PM »

Did you do a dyno run with your engine using an AFM?

bmwman91 · « **Reply #76 on:** January 04, 2007, 11:19:09 PM »

Yup. I did one all-stock, one with the MAF and airbox, and oen with the MAF and a cone filter. Amazingly, all-stock performed best. "Worst" was the MAF + cone...3ft-lbs less all across the board. The even drop in torque leads me to think it was sucking hotter air...a density change seems to be the only thing that could cause such a consistent pattern. The AFR was not constantly different so my maps were probably OKish.

m3someday · « **Reply #77 on:** January 05, 2007, 03:13:17 AM »

.....But!....what are the figures like? could you post your dyno sheet? i'll try to post up mine with the MAF once i can get a scanner. (prob is, i did not do a dyno at all with the AFM!)

cheers man!....don't get dissapointed, there's a reason why the later model engines all came with MAFs, there must be some benefit....if not in terms of power gain, in other departments like reliability, response, accuracy or even cost. i know for a fact that MAFs are way cheaper than AFMs.

Vladi · « **Reply #78 on:** January 05, 2007, 07:23:56 AM »

You should have dyno'd it without any air filters and see where did the restriction come from.

A cone filter without an apropriate cold air intake is worthless. Actually, worse than stock box.

bmwman91 · « **Reply #79 on:** January 05, 2007, 10:11:39 AM »

Quote from: Vladi;16840

You should have dyno'd it without any air filters and see where did the restriction come from.
A cone filter without an apropriate cold air intake is worthless. Actually, worse than stock box.

Yes, and I have the proof lol.

m3someday, you are right. The non-power benefits are all there...I just need to see if I can get the thing to be as good as stock on the dyno. It does not seem to matter in the least what benefits something has...if the dyno numbers do not look good, nobody will be interested, at least in general. The MAF conversion is like choosing an M42 over an M20...the M20 has more power and all, but the M42 is just more responsive and rev-happy. Oh well, after relaxing this weekend maybe I will feel recharged.

bmwman91 · « **Reply #80 on:** February 05, 2007, 01:37:34 AM »

Well, although the dyno results have kinda made this dead in the water (as far as marketability), I figured I would update anyway. I had a spare airbox on hand, so I did some cutting to get a 2 3/4" OD velocity stack running into the top half. The car now runs without bogging dangerously at all RPM's WITH the factory airbox. The rig is still a little ghetto, but after another day or 2 on the mill & with some welding I should have a bolt-on adapter plate for mine. Maybe I will feel like dropping another $85 at the dyno again someday.....

tim_s · « **Reply #81 on:** February 05, 2007, 11:17:28 AM »

Quote from: bmwman91;16796

Honestly, from what I am seeing, a MAF will make the exact same numbers as a stock AFM. Maybe the MAF would be better sold as a replacement for a worn out AFM lol. I suppose I am just annoyed about the power numbers. The car is still more fun to drive with the MAF.

this is exactly what I saw when I dyno'd with and without an AFM. I've had a lot of people say things to the contrary, so in a way I'm glad you back up what I've seen, although I am sad for you that after all your good work you're not seeing more power. Using some drain pipe duct taped to the airbox (perfectly sealed, good as a temporary rig up) I got exactly same power as with the AFM. I also saw no vacuum at WOT with the AFM, unlike the S14 etc, so saw no reason to believe that the AFM was incorrectly sized. dropping the AFRs from the factory 13.7:1 down to around 13:1 consistently gained around 4-5rwhp.

bmwman91 · « **Reply #82 on:** February 05, 2007, 01:14:47 PM »

Yes, this is pretymuch what I was seeing as well. Back when I had a megasquirt on my first M42, I say NO vacuum at WOT, even with the AFM on there still.

Like I said. I still feel it to be worth the time & trouble, just for my own personal knowledge and whatnot. The car also responds faster now, and my mileage got better. Well that, and no more misfiring due to a worn out AFM lol.

Ramblin MAn · « **Reply #83 on:** February 19, 2007, 01:52:33 AM »

I pretty much don't know shit, but I think you have something that just needs a little tweaking to be exactly what you and everyone else is looking for. (thats supposed to be encouragement)

I only have one maf car to take experience from. The maf is at least 8 inches away from the airbox and the airbox itself is designed with the velocity stack built in. On the other side the maf is 5 feet from the throttle plate with a turbo and intercooler in between.

One thing that always came up in discussion was turbulence to the maf. Some people talked about removing the protective screens because they cause turbulence.

I'm talking about my old SAAB, but she really gets up and goes. But aside form that there is absoulutely no hesitation or bogging and she runs really smooth.

All I'm saying here is that maybe it's worth the time to see if maf placement makes the difference you ar looking for? Add some extra tubing to help smooth things out.