Is Stock Maf Ok With 70mm Tb?

pissedoff92

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Aug 14, 2011
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Got a 70mm BBK TB and cobra intake setup for my weekend project. Will the factory MAF be fine with this setup or should I go bigger? This is somewhat of a grey area for me.
 
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NIKwoaC

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The stock MAF is very restrictive, even on a stock motor. It definitely couldn't hurt your setup to look into buying a bigger aftermarket piece.
 

pissedoff92

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Aug 14, 2011
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western new york
reccomendations on size and brand? I plan on an S-trim and trick flow top end over winter so I'm trying for a good foundation now, so that I dont have to buy everything all over at a later date.
 

NIKwoaC

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I have an Abaco 97mm in my car, and it was plug-and-play with 30lb injectors and has worked flawlessly with zero tuning. The nice thing about the Abaco meter is that even with its enormous size, it meters air very well.

I have also heard good things about Pro-M, or you could always go the LMAF 90 route if you plan on tuning the car.
 

reldla1996

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May 4, 2011
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Dayton, Ohio
MA should be a little larger than your TB, though if you're planning on a s/c, you need to think a lot bigger (and the 70mm TB should probably be bigger as well). I went with 90mm ProM.
 

stykthyn

I want to measure mine. It doesn't look that tall.
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For your current set up a 94/5 maf would be the smallest i would run.
 

1987stangman

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Jul 12, 2006
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For your current set up a 94/5 maf would be the smallest i would run.
I was gonna say the same thing. Plus you can find them at the j/y or e-bay for way cheaper than you could by a new aftermarket.

I run a Accufab 70mm with a Pro-M 80mm but I used a Sn 94/95 maf for a year or so until I got the Pro-m.
 

jrichker

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How you you like drinking a really thick, cold, milkshake through a skinny, dinky little straw? When you have that answered that question, you will have answered your first question.

The MAF body and sensor are designed to match each other. Therefore you can't swap sensors between different part number MAF bodies and maintain proper calibration. The assembly is designed to match the computer’s internal program, and swapping a different MAF can upset the computer's calibration. In other words, your monster MAF probably won't match the calibration of your 5.0 Mustang computer.

The OEM Ford MAFs are not calibrated to injector size. The injector sizing is done in the computer’s internal programming. Aftermarket MAF’s “lie” to the computer in an attempt to fool the computer into changing the injector pulse on timing to match the increased airflow.

The only other MAF that is a one for one swap for a 93 and earlier 5.0 Mustang is the 94-95 Mustang MAF.

94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

Once your replacement 70MM MAF is in place, disconnect the battery for about 10 minutes. When you reconnect the battery and start the engine, the computer will relearn the settings for the new MAF.

*1.) Metal flange adapter http://www.kustomz.com/cat3.html Buy the TR70 for $44.95. Or spend some time on eBay looking for one that may fit.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.
 

TurboMustang370

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Nov 26, 2000
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Is the 70mm mass air meter found in the "cobra" kit from FMS the same? I purchased the kit years ago (6+ years ago) from Summit and it came with the mass air meter, 24lbs. injectors and the "cobra" eec. the eec SUCKS, I just ran the stock computer with the ma meter and 24's.
 

jrichker

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Is the 70mm mass air meter found in the "cobra" kit from FMS the same? I purchased the kit years ago (6+ years ago) from Summit and it came with the mass air meter, 24lbs. injectors and the "cobra" eec. the eec SUCKS, I just ran the stock computer with the ma meter and 24's.
The OEM Ford MAFs are not calibrated to injector size. The injector sizing is done in the computer’s internal programming. Aftermarket MAF’s “lie” to the computer in an attempt to fool the computer into changing the injector pulse on timing to match the increased airflow. The Ford Cobra computer uses 24 LB injectors by virtue of the changes in the computer’s internal program to accommodate the injectors.