Mass Air Flow help

[Pimpdady753]

ok im going to be getting this tb and egr plate. http://cgi.ebay.com/ebaymotors/ws/eB...948030174&rd=1 or do i have to get this one. http://cgi.ebay.com/ebaymotors/ws/eB...946621807&rd=1 the EFI one.
when i do get this do i have to upgrade my mass air to get any real hp. also do i have to upgrade my injectors if i get a better mass air. Thanks alot.

[ModMech]

No, if you change you MAF you NEED a computer chip or reflash to correct the transfer function stored in the EEC for your factory MAF to change it to the correct function for your NEW MAF.

Despite claims to the contrary by many (disreputable IMO) aftermarket companies, Ford MAFs ARE NOT, and NEVER HAVE BEEN "matched to XX# injectors), and the Ford EECs DO NOT work that way.

[Pimpdady753]

so should i get a mass air flow, what does it realy do.

[SVTcobra306]

Originally Posted by ModMech

No, if you change you MAF you NEED a computer chip or reflash to correct the transfer function stored in the EEC for your factory MAF to change it to the correct function for your NEW MAF.

Despite claims to the contrary by many (disreputable IMO) aftermarket companies, Ford MAFs ARE NOT, and NEVER HAVE BEEN "matched to XX# injectors), and the Ford EECs DO NOT work that way.

So how exactly do they work then? I'd like to see more info on this. I'm running 30 lb injectors with a Pro-M cal'd for them. It will smoke black with a stock MAF, so tell me you can't have the MAF and injectors match.

Not that it matters to me and my TwEECer anymore, anyway....I just change my MAF transfer function and be done with it.

Basically, you can do it either way, either trick the computer or reprogram it. C&L tricks the factory MAF electronics with a sample tube, and Pro-M tricks the computer with re-curved electronics on the MAF. Either way, it gets you a lot closer than just throwing in injectors and trying to drive it until you can get it chipped.

Back to the original queston, you can install a larger MAF without changing injectors, and you don't need an injector upgrade until you do H/C/I swap or a power adder. 19 lb injectors will get you into the high 200 HP range, which is about all you'll get out of stock heads N/A.

[Pimpdady753]

so your saying i cant get 300hp out of stock heads, even if i have a bunch of other stuff.

[SVTcobra306]

Not very easily without a power adder. Stock E7's are really a bottleneck.

It's been done, but you'd have to do an awful lot and likely get a cam ground with untouched stock heads in mind...

I do not foresee you outgrowing 19 lb injectors with stock heads, esp. if you get an adjustable pressure regulator.

[Pimpdady753]

ic, thanks alot.

[ModMech]

So how exactly do they work then? I'd like to see more info on this. I'm running 30 lb injectors with a Pro-M cal'd for them. It will smoke black with a stock MAF, so tell me you can't have the MAF and injectors match.

OK, I will.

That's a LIE propigated by disreputable (IMO) firms wanting to sell you something that they really cannot make work PROPERLY.

The Ford MAF system is based on a meter that measures the MASS of the air entering the induction system. Each MAF is CAREFULLY calibrated to the entire intake system on a specific vehicle. Doing something as seemingly innocent as installing a larger TB can cause the factory MAF to read incorrectly, or rotating it 180* can in SOME CASES improve it's accuracy.

Now, they have thirty (30) descrete "points" in the function, each point represents a given airflow MASS, no data is available between points. No two MAF p/n's have the exact same data points.

The EEC uses MAF signal to calculate what? I know do you? What other functions does the MAF affect? I know do you?

Let's list some: Trans shift schedule (A/T), upshift light (M/T), spark, fuel, WOT enrichment. There are others, including individual emissions systems.

So, you thinking (wrongly) that to make 300 HP you "need" bigger injectors for your 4.6L. You (wrongly) install 30# units (WAY too big, just so you know). Since your EEC thinks (and was programmed for it) that it is driving 19# factory injectors at the factory regulated pressures, you must LIE to the EEC either by changing sampeling tubes or messing with the MAF signal to make The EEC *think* it is injesting LESS air MASS than it really is by a fixed ratio of (old/new) injector size. So, the EEC will wrongly calculate how hard you are pushing the engine because you LIED to it, and even at WOT it will NEVER figure out that you are at WOT, so you will NEVER get "full throttle enrichment" as is necessary to prevent cat melt-down and excessive spark knock. Now you say "I don't hear any knock, I'm fine" OK. The TRUTH is that you will NEVER hear knock at mid to full throttle until it is WAY PAST too late, and the damage is done. The hypereutectic pistons are like glass, and the top ring lands are VERY prone to breaking under knock.

You see, the MAF is the "god sensor" for Ford EECs, you mess with it, and you just messed with EVERYTHING the EEC thought it knew, and all it's calculations. Oh, don't tell me the TPS will get you to WOT enrichment, it won't.

Go right ahead and install your large injectors, and lie to your EEC. WHEN (not if) you break it, don't say you were not warned that it would happen.

Oh, BTW, tweeker might get you buy, IF you know how the EEC works. But, if you did, you'd not lie to it, so I respectfully suggest you let a pro, like those at www.sctflash.com do the tuning. Unless money is no object, and you like walking.

[SVTcobra306]

OK genius when did Ford put a 4.6L in my 94 Cobra?

I don't have A/T shift schedules, I don't have a M/T upshift light (unless you count my Autometer shift lite, which the EEC has no Idea exists), Cats to melt down, or Hypercraptic pistons to break ring lands.

I've been running 30 lb injectors at slightly less than stock fuel pressure with extremely good results for a year now. I was running the STOCK 24 lb injectors at elevated fuel pressure until I smoked a piston (ran lean and scored it, with stock H/C/I and some bolt ons). Hence a set of SRP pistons and bigger injectors.

I am learning fast how EEC works, and working with it in the real world and getting results that I'm happy with.

My TwEECer will get me by and save me a hell of a lot of cash over SCT.

I guess Ford wrongly installed 24 lb injectors on all the Cobras, huh?

Sorry if I seem to be an unbeliever, but people have been changing MAF's and injectors together since the early 90's, and you're the only guy I've EVER heard say it is wrong.

[ModMech]

I guess you don't listen to the people that really know then do you.

Ask ANY Ford engineer if the MAFs are calibrated to some injector size, they will ALL tell you that you are wrong, that they ARE NOT, and NEVER have been.

I get my info straight from the folks who design and program these cars, not from some tooner who cobbles something togather that might, or might not work.

You still will never get to WOT enrichment, because you lied to the EEC. Have fun getting around that. It's easy if you do it the right way, and a nightmare if you don't.

BTW, the 4.6L did not debut in the Mustang until 1996.

You still do not need anything bigger than 19# (stock) injectors for 300 HP, but you are on the very edge. At the 300 HP level, 24# are much safer.

[SVTcobra306]

WOT enrichment is cake. It's called a dyno tune. I have 3 different ways on my car to adjust my A/F while it's in open loop, and 1 way to adjust it while it's in closed loop. I'm considering installing a pair of widebands to keep a good eye on everything...

You obviously have quite a bit of knowledge, I don't want to flame you, but now you've contradicted yourself, AND your advice is to run on the ragged edge with fuel injector size? Not smart on a real-world driven Ford.

I get my info from guys who build and race these cars, not people who designed them to be held back for emissions and transmission reliability purposes.

Bottom line, like I said before, we've been swapping MAF's like this for YEARS and it doesn't cause engines to blow. If it did we'd all know about it by now. Over on the corral there are literally thousands of quick Mustangs and a huge huge wealth of knowledge, and I'll bet that well over half of us have an aftermarket MAF, with or without larger injectors.

BTW I know darn well when the 4.6 debuted in the Mustang. It appeared that you didn't.

I'm done here. Pimpdady, with stock injectors a larger maf simply flows more air for ya.

[ModMech]

In order to get to WOT enrichment, the EEC needs to see a demand for it. When you lie to the EEC, like you advocate, it will NEVER get to WOT enrichment. As with most things in life there is the right way, and the other way. In nearly every case, the right way is more money and effort, but yeilds better long-term results.

BTW, you never said who at Ford told you that "injectors are matched to a MAF". The reason you did not say, is because THEY ARE NOT. But, I guess if you post it enough it must be true.

Oh, where did I contradict myself? I clearly said you do not NEED larger than stock injectors for 300 HP, and you do not. There are PLENTY of 300 HP 5.0s and 4.6Ls out there on 19#s. Do they have any "reserve" if the fuel pump is weak or an injector is partially clogged? No. Therefore 24# are "safer", but they are not "necessary". That is no contradiction at all.

As you have done, you can mearly force the fuel you want, but that does not change the fact that the EEC is NOT operating in a WOT enrichment mode.

Doctors used to just amputate your arm because they believed that with severe injuries it could not be salvaged. Pretty much everyone knows by now that that is untrue. Some people still refuse to believe though, I think that it is time to move into the modern age.

When a person truely understand how a Ford EEC works, and why, they will not lie to it to force an unnatural situation, they will use the parts as designed and enter the correct functions or tables for the parts used. Simple, elegant, but not always the cheapest method.

[eillob]

Mod mech you speak of these mass air meters like there your children. What are you the voice of mistreated mass air meters. I don't doubt your info maybe we are lying to out computers. So what, bottom line is it works. The stock mass air meters are only designed for the minimum airflow necessary to achieve the factory's horsepower goal. Increasing the airflow requires are larger mass air meter. Larger mass air meter means more air, more air means more fuel, more fuel means larger injectors. Larger injectors means your gonna need a calibrated mass air meter. I've been using one now for three years with no problems. I know guys who have been using them way longer that that, they have no problems. If you wanna pay someone to do custom tunning later down the road thats fine. But there's nothing wrong with getting a calibrated mass air meter for the use of larger injectors.

My opinion and EEC tuner would net you the same results. Taking your car to a shop and getting a custom tune would net you even better results because there's a dyno involved.

And another thing you can be informative without being a dick. I can, CAN YOU?

[ModMech]

Nope, and I don't try.

If people want to f&ck up their cars, GO AHEAD. Just don't tell everyone else that it is a "good" or "ok" idea, because anyone who messes with the MAF signal is a FOOL. I don't care if I p!ss off those that think I'm wrong (I'm not BTW), AS LONG as I give out true and accurate infor so the people are warned about the dangers of idiotic mods like this, I am satisifed.

[eillob]

OK wait a minute, cause I can see this might get ugly. And if it does thats fine too but let me make sure I understand you first. You said

"Each MAF is CAREFULLY calibrated to the entire intake system on a specific vehicle."

Now I don't know about all that. The mass air meter isn't all that complicated. Theres two spings inside that sensor, one measures the temp of the air comming in. The other is keeping the hot wire at a constant temp. Less voltage for low airflow and more voltage for more airflow. Once the meter determines the mass of air it sends that info the computer. From that other things are determines injector pulsewidth, duration, timming etc.

Wake up dude were talking Mustangs here not Lexus's.

"so I respectfully suggest you let a pro, like those at www.sctflash.com do the tuning. Unless money is no object, and you like walking."

Really?

So unless I let those clowns do the tunning my car is gonna blow up right. Dude do you work there or somthing?

Dude anybody with the right equipment and knowledge of the EEC computer can get in there and tune that computer. Ever here of a dyno tune. And as far as Mass air meters go yes if you change for one calibrated for bigger injectors it is tricking the computer but it does work. You will be able to run larger injectors. I've never heard of anyone harming there vehicle.