Granatelli MAF

[scotts94_z28]

I've heard that aftermarket MAF sensors wont work as was wondering if my granatelli MAF sensor could be hurting my cars performance

[DJ Taso]

It doesn't hurt performance. Actually, it only works if your car's heavily modified, so I've been told..

[wolfdogs]

it wont hurt. but it doesnt do any good.......

Injuneer has all the kick booty data on that.

[Injuneer]

From everything I've read, the GMS "in theory" works by recalibrating the indicated air flow so that it under-reports the flow at WOT, and leans out the A/F ratio. The stock PCM programming target A/F ratio in power enrichment (PE) mode usually works out to about 11.7:1. That's too rich for peak power, which is normally made closer to 13:1. The mail-order tuners like pcmforless, and madZ28 will generally be able to produce about 15HP increase simply by leaining out the stock tune.

IF.... IF... the GMS recalibration worked correctly, it should be able to produce the same 15HP increase. But from what I hear, the "recalibration" appears to involve some physical alteration of some the stock MAF sensor's internal circuitry.... not a true electrical recalibraion. Apparently this make it a sort of "hit or miss" end result.

All this is fom "what I've heard".... at least the details of the Granatelli. The info on the stock PCM tuning and the power to be gained is factual.

You need to put the car on a chassis dyno with a wide-band O2 analyzer and find out whether you have an A/F ratio that is hurting you.