Hey guys I have a 1993 F150 x-cab 4X4 5.0 AOD with the speed density system on it, I would like to know if there is a benefit of MAF over speed density and what that might be. If there is does anyone make an aftermarket kit for my truck. Thanks alot




1993 F150 4X4 Xcab
2000 Expedition 2wd
1974 F100 Ranger 390 C-6

And my brother has a 02 Lightning that i get to drive sometimes

 

In a nut shell, it does yeild better throttle response and fuel milage, but don't expect any performance gains with it. Ford makes a kit and it's quite pricy. Another option is to find a wrecked F-series V8 that has mass air and yank the entire harness and ECU.

Try doing a search on this, theres a boat load of info regarding the two....enough to make your eyes burn I'm sure.

 

Mass air is not the savior many claim it to be. Ford's implementation of mass air 96 and earlier was mediocre but much more advanced than similar year speed density.

Some people report better mileage, some better throttle response and both can be acheived with speed density systems with some tuning software and some knowledge of how EFI works.

Mass air is an excellent upgrade if you're changing the cam - the more overlap you have the choppier the vaccum will be, which speed density EFI relies on. If it's choppy, the EEC will see "random" values and won't be able to make the appropriate corrections. This would be most noticable at idle and off-idle RPMs. Once you've achieved enough RPM whereas the flow is fairly consistant, the choppyness goes away and the EEC can manage the engine better.

Mass air, because it measures the air going in regardless of the cam, gives a more accurate reading because vaccum choppyness is basically irrelevent, so you can run as much overlap as your engine can handle in conjunction with the data tables inside the EEC.

The throttle response issue is often attributed to mass air... but actually it's the code/data that scales the throttle position sensor's output to a numeric value. That's easily changed (with software) in the speed density system so you can have as much throttle response for given pedal travel just by changing some parameters.

You can also change this mechanically BTW, simply make a clamp and move the throttle position cable's end on the throttle body closer to the pivot. Or, create an egg-shaped metal thing that the cable pulls around, so you've mechanically created an exponential relationship between pedal travel and throttle body movement.

 

By using software do you mean chips or a computer tuning. I have considered getting a chip installed but there are not many options available. Thanks for the help

 

Hey bud go to page 3 . There was a pros and cons search of Maf lots of good info. Its almost to bottom page. I posted on it how I converted my 93 302 engine wiring to work in 94 f150 w/maf Good luck_ P.S. I never have luck with the searches
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94 F150 XLT 4x4 SC LB Maf 302 E4od

 

By software I mean EECeditor and some hardware (moates.net) or Tweecer which has hardware and software, but more money.

I'm not a fan of installing a chip for a few reasons.

1. When you have a chip made, it's made based on what you tell them. While it might work much better than stock, it's not necessarily guarrenteed to be "optimal".

2. If you decide in a few months to a year, to upgrade the engine parts, install a supercharger, turbo, nitrious or what have you, you'll need to have the chip maker burn a new chip. Of course this adds to the potentially "not optimal" situation above.

3. You can't adjust it yourself. This might not be a big deal for many people who only get the basics of how EFI works, which is fine. Some people are happy buying "bolt ons" and spend their time enjoying their vehicle. Other people (like me) would rather tune the vehicle myself to squeeze every bit of MPG and HP out of the vehicle I can, through software. Of course as I change things, buy upgrades, port the heads and so on, I can easily calculate what I need as far as fuel and adjust the timing and fuel tables accordingly. I can also enable and disable different functions. For example my 93 crewcab doesn't have air conditioning, but the EEC still (dis)actives an imaginary AC clutch under certain loads. Once I edited the tables quite radically for this function, the AC clutch connector now illuminates a light bulb once the load on the engine reaches a certain point. After lots of guessing, I finally got it to consistantly light when the truck is getting less than 12mpg, since I'm particularly interested in getting the best mileage through driving habits with my highway hauler.

Once you get really into the nuts and bolts of the EEC, you'll find a lot of similarities between units as well as interesting differences. For a while I had an "adjusted" 5.0L town car EEC in my crewcab which didn't buy me a heck of a lot except that that particular EEC had code in it for an air suspension. This was important when i was experimenting with installing air bags in the rear, and I wanted them to "auto level". Load the truck down, it airs up. Empty the truck, it airs down. I was interested in this because when the butt of my crewcab sags with about 3800-4000lbs in the bed, my alignment gets so far off driving on the freeway is tiring with all the corrections I have to make as a driver. Got the code working, just not the mechanicals yet.

Anyway, just trying to share what can be done with tuning. Depending on the EEC, you're not limited to just engine stuff. You can adjust tranny shift points and other behavior if your truck has an Exxx automatic, for example. If you don't have AC you could use the EEC AC enable/disable output to control air pressure valves for an Air locker. High load on the engine, the rear locks solid. Smoking tires is a high load

 

There's alot of good info here, but we really need to know what your plans/goals are for your rig. Do you plan on keeping this a bone stock motor, adding some bolt-ons, and/or doing a rebuild with aftermarket performance parts?

Any details/plans you post will definately help.

 

my plans are to rebuild the bottom end basically stock and put in a mild rv like cam for torque because as of now with 3.55 gears i have no bottom end to pull my boat witch is a small boat, and maybe a better set of heads and intake. I really just want the truck to pull decently with decent fuel economy, not really looking for alot of speed.

 

Frederic, I already had a lot of respect for you and your knowledge of Ford EFI systems. After reading your last post, I'm starting to think you need to seek some help...

Jason

 

Stock speed density can handle heads, a mild cam and intakes. But some type of tuning will help tie everything together. If you don't like the idea of tuning it yourself, then this is where you may run into problems; there's only a small handful of people in this country that can tune stock speed density, using GEN 1 Lightning databases and strategies. Not a big deal but with a mail order chip, it wont be spot on, but better than no tuning at all.
It'll be easier to find someone to tune a mass air system and it'll adapt to climate/temp changes better than a speed density system will, especially under heavy throttle/open loop. This option is more expensive, but has a better potential, especialy with aftermarket performance parts. For a stock rebuild, your speed density system will be fine, even with a mild cam. If your plans are to upgrade to better flowing heads and intakes, then you should use that when considering a mass air swap.

 

I consider frederic to be a fanatic when it comes to these trucks. The info he posts can be a little overwhelming for some, at times. However, to me, that just shows how passionate he is about these trucks and helping others, and I like that.

 

'Twas said tongue-in-cheek. I'd love to poke around my truck the way he does his (one BIL is a mech. engineer, the other is an elect. engineer), I just don't have the time, and, well, if it ain't broke, I'm not fixing it.

Jason