MAF talk.

[zach44102]

Looking into upgrading my MAF, I am wanting some feedback on what I have been researching for the past couple hours. So I have a chance to pick up a 70mm MAF from a Mustang Cobra (94-95). Very close to the 73mm C&L units. Now here that people have been using the C&L units for a long time, some with good results, some with bad. But the problem is that they are using the stock 55 units that trick the car into running lean since its not metering all the air entering the motor. But who has tried changing out the sample tubes? Seams to me if I upgraded to a 70mm housing with the 19#/hr sample tube from a 87-93 mustang it would correct the lean condition. Correct me if im wrong.

Yes i know this is not going to give me a higher peak hp. Im looking more for a flatter tq/hp curve from 5600-7300. power drops off around 6500 and You can tell the car has trouble breathing at higher rpms.

"One thing to keep in mind is that the stock '87-93 Mustang 5.0L uses 18.47 lbs/hr @ 2.7 BAR or 39.2 psi static flow rated injectors.

If you do the math; 8 x 18.47 = 147.8 lbs/hr

Now 147.8 lbs/hr / 6 injectors = 24.63 lbs/hr

That is pretty darn close to the 3.0L SHO which uses 23.7 lbs/hr @ 2.7 BAR or 39.2 psi as well as the 3.2L SHO which uses 24.3 lbs/hr @ 2.7 BAR or 39.2 psi static flow rated injectors."

 

[yamahaSHO]

If you're going to get a different MAF, pickup a Lincoln or Lightning 80mm MAF and use a TwEECer/BE to input the correct curve and scale it in properly with logging. Trying "match" one to the injectors, especially, using sample tubes will likely make the car slower everywhere else. Even a stock MAF could use tuning due to the variances in MAF builds, engine build, age, etc and the fact that the stock curve is generic. It should be very close, but differences in coming out of the factory are dealt with by PCM correction.

The MAF won't help your power significantly up top as you're fighting against the limit of the cams for the most part.

 

[Mr Anonymous]

"MAF-101" for morons:

This is 2011, not 1990.

Back in the late 80's and early 90's, when EEC tuning was in its infancy and things like a TwEECer were not even conceptual and the one or two chips out there were expensive and couldn't access 90% of the calibration, a MAF swap was the primary way to "trick" the PCM's load and fuel calculations for more power.

To make it simple for the uneducated masses, they were sold "matched" to injector size since most fuel tables using the same flow injectors were the same across multiple PCMs and platforms.

Once EEC tuning became available to the masses, the significance of changing MAFs became strictly limited to the need for better flow, resolution and accuracy.

Companies like Pro-Flow (whatever they're calling themselves these days, PMAS?) still use this 1990 mentality and keep the myth alive in the peddling of their products. All their junk does is provide the PCM with fake data via the stock transfer function in order to change its fueling strategy. A tuner will do this far more effectively.

This sample tube ******** with the C&L/Vortech MAFs is just more of the same: A way to manipulate the airflow over the hotwires to provide the PCM false data upon which to base its fueling and load calculations.

Ingrain this into your brain: A MAF IS NOT A BOLT-ON MOD.

Changing MAFs is a complimentary mod. In other words, it complements other mods that actually make power, and require more airflow along with more accurate air metering. Adding cams or a blower or larger pistons or anything that requires and can take advantage of increased flow? You'll probably need a different MAF (which, BTW, most any 80mm Ford MAF EEC-IV or V will usually do the trick). Got a stock engine with a stock PCM? Your stock MAF will work just fine. Buy a tuner; it's a far more worthwhile investment.

I can tune a stock SHO with a stock MAF to make just as much power as it could no matter what other MAF you bolt on, because I can manipulate the PCM calibration to do what it needs to in order to make maximum power. What MAF is attached is IRRELEVANT to my tuning other than having a base transfer function to begin with. Once I get the transfer function nailed, the PCM is going to meter the air accurately, and whatever fuel and spark I've configured the PCM to apply is going to impact the power, not the MAF.

The bottom line is simple: If you think bolting on an aftermarket MAF is a meaningful way to make your engine to "breathe" better and make more power, you've got no idea what you're talking about and should stop and keep reading until you understand how the Ford EEC works.

 

[Bob Gervais]

But.... can I just solder a resistor across the hotwires?

 

[SeanMc]

I basically told him on FB that if he isn't making 300hp, the stock MAF is just fine. He insisted that it was a restricton. I just gave up. While I may not be a mechanic, I do understand some theory....and I daily drive a HC cammed 3.3L and have been through a lot with it over the past 8 years. Even with all my mods, I was at about 90% (according to the tweecer) and went to the 80mm just to get it back into the "safe" territory.

 

[SHOtime2511]

I had a Pro-M maf with great results back when my 90 was N/A.
They are hard to find and fetch a pretty penny when you can find one for sale.

 

[jayro]

If you dont have a way to tune it properly I would suggest staying with the stock one. As already has been stated the biggest thing holding you back above 6500 is your cam profile.

 

[hawkeye18]

Your engine, no matter how pretty, doesn't make enough power to necessitate an aftermarket MAF.

/thread

P.S. I have a Pro-M 75mm MAF, because I scored it for $40 on ebay and it was too good an opportunity to pass up like 6 years ago. No, you can't have it.

 

[Mr Anonymous]

I had a Pro-M maf with great results back when my 90 was N/A.
They are hard to find and fetch a pretty penny when you can find one for sale.

Which again, before real EEC tuning was readily accessible and affordable was one way to do it "back when". Today in 2011, unless the MAF is stupid-cheap and the car is stock with no other mods, there are a number of far superior and cost-effective solutions.

People who pay "a pretty penny" are not too bright if that penny is anywhere close to the cost of a real tuning solution.

That being said, a Pro-M does give you the size increase that may be required with other mods, and I have tuned a car with a Pro-M by getting the transfer function right just as I would with any other MAF. Point being, it wouldn't have mattered if there was a Lightning 80/90mm MAF, getting the xfer function right is key.

 

[Phoenix]

Heh I hope that you're wrong about the PMAS Chris

I just shell'd 250$ in a slot style PMAS (VMP?) recommanded by Josh....and Toolman.



He told me in an email , that the Mark8 80mm is basicly the same as our stocker - the gain is minimal , even when tuned. The differances lies in how much points it can carry in the maf curve graph. More points = more precise.

Thats what he told me , I know next to nothing on these things.

 

[Mr Anonymous]

The slot-style is an exception mainly because of the pipe that it comes in, but also because the PMAS offers better resolution than the Mustang slot MAF.

It's still not a stand-alone bolt-on mod however as far as this discussion is concerned.

BTW your tip went in Canada Post yesterday morning.

 

[jayro]

Heh I hope that you're wrong about the PMAS Chris

I just shell'd 250$ in a slot style PMAS (VMP?) recommanded by Josh....and Toolman.



He told me in an email , that the Mark8 80mm is basicly the same as our stocker - the gain is minimal , even when tuned. The differances lies in how much points it can carry in the maf curve graph. More points = more precise.

Thats what he told me , I know next to nothing on these things.

I think another big plus to the slot style besides the resolution is that it is much more ideal to use in a BT set up.

 

[thxone]

Of all the Mustangs (fox bodies) that my buddy has owned (9) of them, the only time he would swap out a MAF over the stock unit was when he would add the following... Which was only 3 times.

* Headers, high flow exhaust and two chamber 40 series Flowmasters
* 3.73:1 Gear
* 24lb injectors
* Cobra upper and Lower intake
* Ford Motorsport E303 Camshaft
* 10 or 11lb flywheel, I don't remember which
* 1.6:1 Roller Rockers
* 70mm TB and Spacer
* BBK Fender mount CAI

When Dynoed was still well under 300hp at the wheels. But it was a fun car to drive and ride in. The one main item that made him get the MAF was the camshaft. More air in, more air out. This was on his '92 LX coupe... now his '95 GT was a different story at 411hp at the wheels. I agree that more than stock is not needed as far as the MAF unless you are pumping much more air and fuel through the engine.