Black02SS

iTrader: (36)

I was tuning a car today and we tried a test to see how much of a restriction the MAF was on a car. I am not talking SD/Non-SD as the car is in SD. I know several are runing SD, but still have the MAF in place, just disabled. On this car, we did a run with it in place, and then another with a 4" tubing and 100mm MAF in its place. Now the MAF's isn't used at all, but the customer didn't have a piece of tubing big enough to use, so he improvised and found this setup. When his new 4" tubing arrives, he will be removing the MAF and just runing the tube. Very good choice on his part.

The car is basically cam only, full bolt on with a 90/90. There is NO change at all in the tune from one run to the other.

Run #5 - Stock 78mm Screened MAF
Run #14 - New 100mm De-Screened MAF and tubing (Bigger) +16hp/15tq
Run #12 - Same as 14 with cutout open +23hp/22tq

Ru2n00n3er

iTrader: (13)

I figured you might put up a thread about this. I'll post up some stuff in the dyno section once I get some time.

svede1212

iTrader: (3)

interesting. i threw my MAF in the corner of the garage a long time ago.

sweetgas

iTrader: (1)

you can get rid of the MAF? How does that work?

foff667

iTrader: (2)

very cool chad...great info

foff667

iTrader: (2)

either set the fail frequency low or remove it then just tune for it

gametech

iTrader: (1)

Just a heads-up. I don't know about other computers, but on the '04 GTO, setting the fail frequ. to zero does NOT turn off the maf. I have no idea why.

Black02SS

iTrader: (36)

It wasn't the fact it was in SD, it was the fact it was in the way as a restriction to the manifold. I was shocked in the results to say the least. I didn't expect it to be that much of a increase. I guess with the 90/90 it just REALLY needs to breath. +23hp/22tq is pretty good increase for mods that cost less then $100 in this case. I will be testing this again here in the future on another car to see if there is any difference. I'd like to see this done with a LS6 manifold as well. I would say there won't be near as much increase as there was on this car.

gametech

iTrader: (1)

Your expectations are irrelevant. You did an experiment, and you had results. You then posted those results for all to see. Good job!

Sean Collins

I don't know what to say. Having seen small 75mm 3 pin NA 347 head/cam car running an ls6 intake make 392lb ft and 437 rwhp on a mustang 1750 De dyno which reads 15-18% lower then your dyno jet and having removed the maf and seen zero gain. I qeustion wether or not your tests are accurate becuase in the time it took to swap it off the air in the dyno cell cleared up enough for a 2-3% power change in the favor of the test.If your really serious about proving this out then put a good quality pressure sensor in the duct and graph it on a run.To boot we are at 1500above mean sea level and the baro was at 28.6 today when this test was performed. Done to satisfy curiosity.

gametech

iTrader: (1)

Either I'm too drunk, or you didn't give enough info about the two graphs you posted.

2xLS1

iTrader: (25)

I wouldn't expect it to be the same restriction in front of a LS6 intake as in front of a Fast 90/90.

Sean Collins

No thats a head cam 347 with headers and an M6 trans.

Sean Collins

If you adjust the power diparity between this mustang dyno and the dynojet this car make almost 506hp and 454tq using 16% as the mean average difference we have charted between the them. We charted Zero change in hp with a 75 85 and 100m Maf and No change without. Nothing that 3 runs could back up when totally STP and SAE corrected. The fast intake is a whole different story.

2xLS1

iTrader: (25)

That was my point. The car in their test had a Fast 90/90. The car in your test has a LS6 intake.

gametech

iTrader: (1)

But what is the difference betweent the two graphs?

speedyss

so your sayin a 100mm maf can flow just as much as a 78mm maf. I say it makes a diff in a engine that has to flow more air, like if you have a fast 90 or more cubes. I bet on all stock stuff like ls1/ls6 parts the 78mm is the threshold, any bigger and you gain nothing, any smaller and you lose. So an engine that needs more (flows more air) will benifit from the bigger maf, like fast 90.

Black02SS

iTrader: (36)

I'll agree here with 2xLS1. I wouldn't expect to see that much if any of a gain doing this test on a LS6 intake. Basically with the 90/90 setup it is like sucking a marble through a straw. With the LS6 setup, you have the same size opening as you do for your intake, hence no restriction or VERY little IMO. Could also be such a thing the cam that he had custom spec'd for the car really likes the extra air more then others.

speedyss

Thats exactly what i was talking about, i agree.

svede1212

iTrader: (3)

i believe the area i measured in my MAF was slightly smaller than the area of the TB. the MAF bracing is larger than the throttle blade and the screening makes it worse also. altho you can make "X" HP with a MAF doesn't mean it flows just as easily with or without one. i don't find the test too surprising at all. good post