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Discussion Starter #1
something i am considering now as far as which direction to head with next line of mods has lead me to a more practicle and affordable method which oddly enough is a single turbo set up on my 5.0 bird. Now i know its a basically stock drivetrain but i'm toying with the notion of installing a moderate setup. down here i have friends that own shops that are doing the LSX turbo setups thus i cut the middle man out through the friend network thus the turbo and related parts and tuning would be quite affordable comparing a full list of mods likebuilding the motor NA. I was thinking of maybe tuning out the maf and tuning it speed density, MFU, 42lbs injectors. just throwing it around in my head with out exact numbers but I believe the performance should be pretty reliable until **** starts to break lol.
 

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I dont think an sd system could keep up with what your talking about. Also if your looking for affordable, redoing your whole underhood harness with a computer probably isnt the best way. The early fox body guys switch to mass air because the computer will except some mods. I could be wrong but I think your going in the wrong direction. If you do want a somewhat affordable option pick up a used sc kit from a mustang. Then run it til the motor blows. You will still need a tune.
 

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One thing to consider - with a MAF, the air/lambda calculation is fairly straight forward.

With MAP, there IS no direct relationship, so you have to either look through a lookup or futz around with interpolation. Well, according to Banish, that is.

Why not leave it MAF equipped? That way, you don't have to compensate for the turbo in the tables or anything - it's a direct relationship between how much air is sucked in and how much HP you're producing for any given configuration.

RwP
 

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Discussion Starter #5
the underhood harness is a pick and pull item and spicing is just time consuming but cheap and just like i said why go with a map instead well here goes.
MAF systems use a sensor that measures the air density entering the engine rather that calculating it as with a speed density system. The MAF sensor has a heated wire that maintains a constant temperature.Air flowing through the MAF sensor cools the wire requiring more current through the wire to hold the constant temperature.The amount of current flowing through the wire is proportional to the air mass flowing through the MAF sensor.



MAF systems are used on many current production vehicles. On a high boost, big horsepower turbocharged engine however, speed density is a better way to go_One reason is because MAFs and engine computers a limit to how much of air flow they can read.Tuners can get around this limit by fudging tables, but at this level it is wise to switch to a speed density system.
The MAP sensor on most stock engines is a 1 bar MAP sensor.The atmospheric pressure at standard sea level is 1.013 bar, therefore, it cannot sense pressures above atmospheric.In other words, it cannot sense boost pressure.A 2 bar MAP sensor will sense up to about 14.5 psig, and a 3 bar MAP will sense about 29 psig.Remember that 1 bar is atmospheric pressure or 0 psig.



When tuning for speed density, you will need to replace your stock MAP sensor with either a 2 or 3 bar MAP sensor, depending on how much boost you want to run. 2 and 3 bar MAP sensors can be purchased from Summit Racing and other speed shops.Tuning for 2 and 3 bar speed density can be done with HPTuners, EFI Live, Bigstuff3, FAST XFI, Accel DFI among others.
 

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So, Kids93Bird, you're saying that the MAF sensor on a Thunderbird SC ... doesn't work?

Heh.

Find the transfer and use a Lightning MAF. Problem solved, with a junkyard / OTC part.

Where did you quote that bit from?

But eh. You want to do it the hard way, feel free to. Speed density WORKS, but it takes more grunt to work it up front for adequate performance. MAF, due to HOW it works, is a better solution for most people.

Checking RockAuto - the factory Motorcraft MAF is right at $90. The Lightning MAF, for the supercharged 5.4, is a horribly terribly overpriced ... $138. So, for $48, it's worth fighting speed density instead of the straight line MAF. :facepalm::zdunno:

Of course, Ford never produced a mass production supercharged vehicle that used from the factory a 2bar or 3bar MAF sensor. :sarcasm:

RwP
 

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Discussion Starter #7
So, Kids93Bird, you're saying that the MAF sensor on a Thunderbird SC ... doesn't work?

Heh.

Find the transfer and use a Lightning MAF. Problem solved, with a junkyard / OTC part.

Where did you quote that bit from?

But eh. You want to do it the hard way, feel free to. Speed density WORKS, but it takes more grunt to work it up front for adequate performance. MAF, due to HOW it works, is a better solution for most people.

Checking RockAuto - the factory Motorcraft MAF is right at $90. The Lightning MAF, for the supercharged 5.4, is a horribly terribly overpriced ... $138. So, for $48, it's worth fighting speed density instead of the straight line MAF. :facepalm::zdunno:

Of course, Ford never produced a mass production supercharged vehicle that used from the factory a 2bar or 3bar MAF sensor. :sarcasm:

RwP
never said anywhere on my post that the MAF doesnt work but i guess folks will assume what they want and maybe its because they cant understand what they read. MAP to me equals a more tunable setup not because i say so but because i happen to pick up on the many proven builds here in south florida in the 5.0 pushrod community manny shops that i do work for. Never said any factory vehicles come with 2 and 3 bar maf either but if you read my post youll see where it can be attained from.
 

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*shrug* It's your car, of course. It's just that insisting that speed density is EASIER or even MORE TUNABLE (in an absolute sense) is just wrong.

MAF tuning, due to the straight line relationship between flow and horsepower, is a LOT easier to tune over the entire range.

OTOH, if you have friends who know speed density inside and out, it's easier to use their expertise.

Just be aware they're doing more work.

Might as well go with a supercharger puffer (through a carb) - that was the hot setup when I was a teenager, back in the late 60's. Worked great too.

That won't mean I'd EVER advise that nowadays.

RwP
 

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never said anywhere on my post that the MAF doesnt work but i guess folks will assume what they want and maybe its because they cant understand what they read. MAP to me equals a more tunable setup not because i say so but because i happen to pick up on the many proven builds here in south florida in the 5.0 pushrod community manny shops that i do work for. Never said any factory vehicles come with 2 and 3 bar maf either but if you read my post youll see where it can be attained from.
I started out trying to use a blow through mass air meter on my 93 SC with turbocharged 347 and it was a real pain to tune using SCT and a C&L 85mm tuner MAF. I could either get it to run good at part throttle or wide open but not both. I ended up switching over to Fast XFI with 3 bar MAP, full time wideband o2, ect.. Doing that also required adding an MSD trigger wheel and crank sensor, and switching to a differint distributor, but tuning the car is no longer a problem.

At that time nobody was offering a good blow through MAF, but now you can buy one that is calibrated to whatever injectors you want from Pro-M and from what I've seen it works great and can be easily tuned using Moates QH chip and Binary Editor. You can also switch over to a new style slotted MAF that can be added to the intake pipe tubing.

http://promracing.com/

If you are eventually planning on making big HP, you are better off going to a stand alone SD system like Fast, Big Stuff, of Megasquirt...but if you aren't really planning to make over 500 hp, the stock computer with a blow through MAF will be a lot easier and is very capable.

David
 

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I have a silly question, Dave - why use a blow-through MAF?

Just use an intake MAF off the air box / WAI/CAI intake, as per factory, eh?

Make it a Lightning MAF and he's good to go with that.

RwP
 

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I have a silly question, Dave - why use a blow-through MAF?

Just use an intake MAF off the air box / WAI/CAI intake, as per factory, eh?

Make it a Lightning MAF and he's good to go with that.

RwP
Ralph,

To use a draw through MAF as configured from the factory with a turbocharger requires more complicated cold side plumbing because you can't use a blow off valve. If your blowing off metered air it screws up the tune, so you have to use a bypass valve instead of a blow off valve and large enough hose to carry the air you are exhausting when closing the throttle plate to the inlet side of the turbo's compressor.

So instead of attaching the air filter directly to the turbo you have to use a short section of pipe with a nipple between the MAF and Turbo inlet, and you still have to fit the air filter prior to the MAF. With a larger turbo it usually requires two bypass valves because the volume of air being exhausted is too great for one valve to handle. It's very difficult to fit all that crap under the hood just so you can use a draw through MAF.

With a blow through, you simply plumb the BOV into the cold side pipe somewhere in front of the MAF so whatever air goes out of the BOV doesn't matter because it wasn't metered air. It's much easier to plumb because you don't have to capture and recirculate the air exhausted by the BOV.

Hope that makes sense. If not I can probably find a diagram.

David

PS: Here is an example of a turbocharged motor with a draw through MAF.

http://www.autoblog.com/photos/1995-ford-thunderbird-svt-prototype/#photo-1325598/
 

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No, that makes sense.

I was thinking supercharger there.

My bad.

RwP
 

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Y'all are making this too complicated.

OP, if I were you, I'd just bolt on a centrifugal SC like a Vortech. Also, use a MAF. The factory system can and has been tuned more than sufficiently to handle what you want to do with the car. There are bigger and better MAF sensors out there now as compared to before. I know at least one member here who has been doing it successfully on a 500+ RWHP 5.0L Thunderbird that's running in the 10's for the 1/4 mile.
 
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