90mm Lightning MAF into r32 GTR swap, tuning with afc; questions....

[wyldemannn]

First off, r32 gtr into s14. We've got a s-afcII installed, and ditching the factory twin maf in favor of a 90mm lightning maf. Nissan and Ford both run 4 wire setups; 12v ign power, ground, 5v signal in to the meter and a signal return to ecm. The problem we're having is, none of the preset sensor numbers are anywhere close to the airflow capabilities of the lightning maf. We plug it in and get 58% airflow with key on engine off. Obviously, this is too rich to run. We've tried -50 on high and low maps to try and pull it into the run range but no go.

We're thinking a/b resisting the return signal voltage to reduce the amt of airflow "seen". Anyone else run into this with non stock mafs before? We "think" we might be outside the ability of the s-afc/nissan ecm combo with this setup.

Any help would be appreciated, as this is driving us nuts. If this is outside of the "do-able" area, Megasquirt it is.
Modified by wyldemannn at 12:15 PM 6/29/2007

[gawdzilla]

i was thinking about doing something similar using the pfc, and that was gonna be a stretch already.

my guess is you can't do it on safc cuz you don't have enough adjustability.

on pfc you can change the points on the curve to make your own voltage x airflow curve map, and thats what i planned to do if i had it.

what did you do with the dual maf to single maf change? just parallel'ed the signal so both afm1 and 2 see the same thing? if so it will run rich because of that, not because oyu have a bigger maf. a bigger maf should make you run lean.

[wyldemannn]

the safc has a layout in the manual for single maf to dual output from safc to ecm for dual maf cars, you're saying that won't work? Have you or someone you know already experienced this? What is it about the signal that causes that not to work?if that's all it is, i'll build a y pipe and extender harness to place the mafs down in the bumper and run with the stockers until standalone time.

PS, on an off note, will a z32 maf go in with the safc dual ouput option? if so, I can certainly get one to test.

[Carl H]

megasquirt = gross.i never understood why ppl would ditch the stock eccs computer for something that was inferior.pfc it with an airflow curve from jwt or sit down and figure it out...but dont use an safc.