Granatelli VS Stock MAF Tune Results

[gregrob]

Well we decided to make a run with the granatelli on my buddies 94 firehawk and log it. Then switch to the stock one, and run again to see the results.

With the granatelli the car was runnin rich, would black smoke when you started it cold lol.

Granatelli MAF was 890-910mv on the 02's. Stock descreened MAF it's down to 820-830 under WOT.

Granatelli was 36deg spark advance with 10 deg of knock retard, for 26deg of total advance

Stock descreened maf yielded 35deg of spark advance and only 4deg of knock retard under wot, for 31deg of total advance.

AFGS numbers were much higher with the Granatelli. 210+ vs 160-170 on the stock one.

Car seems to run better to me. It definitely sounds different. It likes to rev a lot more freely, and seems to get through the gears quickly.

With the granatelli it had more midrange 'snap', but seemed like it was struggling to rev. I credit this to the stock maf leaning the car out quite a bit. It actually may not 'feel' as gutsy, but would probably be faster on the track because it gave it more top end.

We had to make 2 runs because evidently unplugging the maf throws the car into open loop mode and the first run we made with the stocker was in open loop lol. The files below are in closed loop for both the Granatelli run and the Stock desc MAF run.

The stock descreened maf is staying on the car and the Granatelli is for sale if anyone wants it.

Here are the TTS Datamaster files if anyone would like them.

Granatelli MAF
http://forddieselpower.com/grfiles/granatellimaf.uni

Stock Descreened MAF
http://forddieselpower.com/grfiles/s...closedloop.uni


Discuss.
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[Speed Inc.]

it has been said many times the aftermarket MAFs are trouble and to keep the stocker

[chevy42083]

Nice to see some work done to back up the argument one way or the other instead of just hear-say jumping from forum to forum.

Although, (and I REALLY don't know), does the car need time to adjust fuel-trims before you could get an honest look? I'm just barely getting into tuning at all, but this is something I've always wondered when people swap them back and forth like that.

[BLOWNDFIZ]

Although, (and I REALLY don't know), does the car need time to adjust fuel-trims before you could get an honest look? I'm just barely getting into tuning at all, but this is something I've always wondered when people swap them back and forth like that.

This is true. To really test the difference the car would need time to "learn" or adjust to the changes before the testing can be truely considered accurate.

However, having owned a GMS unit before there was no real benefit over the stock in my experience with it. So I definitely agree with the OP that it really didn't help.

[gregrob]

We did have a fair amount of driving time to get to a spot where we could make a WOT run after the swap, that and we did one run but the car was in open loop, apparently from unplugging the maf.

So it had a little time to adjust, and I watched the 02 and spark for the next 20mins of us driving the car around and they stayed the same.

[AChotrod]

It took my car a while to adjust to the new tune after the top end build and the same when I added the TDs. Drove like ass at first but then started running like a champ!

[gregrob]

Where should the AFGS numbers be? 96caprice said they're way off.. IDK

[chaser2racing]

will see if we can line up the same race as last weekend to see if theirs a improvement by the way the car feels better smoother and sounds more snappy seems to pull more mph if i ever dyno it all throw it back on and make sure that this 300.00 dollar upgrade is a pos