modifications to a speed density system
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From: Eastern, Iowa
modifications to a speed density system
I have an 89 F-150 ext cab 4wd with a 5.8L and E30D.
How much modification can one do before one starts having trouble with the speed density FI system and therefore needs to burn a chip?
K&N?
Headers?
True dual exhaust or cat back? (or neither?)
Underdrive pulleys?
6-71 Blower with dual Projection units and nitrous? (Just kidding)
Trans mods?
Is there any way I can reprogram the computer now for a little more juju?
I'm in the process of building a nice, torquey, stroked 351 that will DEFINITELY require a new chip, but for now, I want to do all I can to pep this old boy up and will not be going to a '93 Lightning MAF setup in the process. Thanks!
I put this over in "Computers and chips" to see if there is some help offered over there as well ( don't know if one can post the same thread in 2 places.)
How much modification can one do before one starts having trouble with the speed density FI system and therefore needs to burn a chip?
K&N?
Headers?
True dual exhaust or cat back? (or neither?)
Underdrive pulleys?
6-71 Blower with dual Projection units and nitrous? (Just kidding)
Trans mods?
Is there any way I can reprogram the computer now for a little more juju?
I'm in the process of building a nice, torquey, stroked 351 that will DEFINITELY require a new chip, but for now, I want to do all I can to pep this old boy up and will not be going to a '93 Lightning MAF setup in the process. Thanks!
I put this over in "Computers and chips" to see if there is some help offered over there as well ( don't know if one can post the same thread in 2 places.)
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From: Sacramento
no problem for the speed density w/
K&N, any exhaust mods, underdrive pulleys.
speed density has a problem when you change displacement and/or cam modifications.
Reprograming the computer is not really an option on the EEC-IV computer, PROM is soldered to the board. You can get plug in programable modules that plug into the harness between the computer and engine wiring harness, that change the computers output to compensate for engine mods. I've seen them for $200-400.
I would spend the extra money and go w/ the MAF setup. It will compesate for a whole lot of engine modifications. where as going with the harness module if you change your cam you need to reprogram it again.
K&N, any exhaust mods, underdrive pulleys.
speed density has a problem when you change displacement and/or cam modifications.
Reprograming the computer is not really an option on the EEC-IV computer, PROM is soldered to the board. You can get plug in programable modules that plug into the harness between the computer and engine wiring harness, that change the computers output to compensate for engine mods. I've seen them for $200-400.
I would spend the extra money and go w/ the MAF setup. It will compesate for a whole lot of engine modifications. where as going with the harness module if you change your cam you need to reprogram it again.
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Great! I was told those seemingly minor external mods would goob up the system. That ought to help with some short term power needs for sure. To be clear, I can put a high flow air filter and headers on the truck and a true dual exhaust system (with applicable sensors, etc.) and not cause the system to run afoul? I was told by someone that may not have been as intimate with speed density systems as those here that those mentioned mods would cause all kinds of flak.
I have given thought to the MAF setup, but it seems so labor intensive with all of the wiring harness considerations and wrought with potholes if you don't get it right........and I have read here that if you build your motor and give every germane parameter to the chip boys, you can get it right to a gnat's eyebrow. I plan on building the motor right, giving the parameters for a new chip, and leaving it alone. Buy and hold.
Not sure as of this post that it's an EEC-IV computer. Were there other options or was that standard fare in 89?
BTW, what does that stand for - EEC? and also the PROM you referenced?
I have given thought to the MAF setup, but it seems so labor intensive with all of the wiring harness considerations and wrought with potholes if you don't get it right........and I have read here that if you build your motor and give every germane parameter to the chip boys, you can get it right to a gnat's eyebrow. I plan on building the motor right, giving the parameters for a new chip, and leaving it alone. Buy and hold.
Not sure as of this post that it's an EEC-IV computer. Were there other options or was that standard fare in 89?
BTW, what does that stand for - EEC? and also the PROM you referenced?
Last edited by grandaddy's66; Dec 19, 2003 at 03:40 PM.
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From: Eastern, Iowa
Thanks. Pretty straightforward.
If I had a guess, I might say PROM is "programmed read-only memory."
I have read on the chip FAQ portion of this site that headers require a chip
If I had a guess, I might say PROM is "programmed read-only memory."
I have read on the chip FAQ portion of this site that headers require a chip
Last edited by grandaddy's66; Dec 19, 2003 at 04:02 PM.
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Here is the link to the statement about the headers. I would welcome any thoughts on it.
http://www.motorhaven.com/Web_store/....html#modified
http://www.motorhaven.com/Web_store/....html#modified
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From: Sacramento
Sorry I was mistaken, you can reprogram it. PROM does stand for Programable Read Only Memory, and since it can be reprogramed, it has to be an EEPROM (Electronically Erasable PROM).
I find it hard to believe that headers require a reprogram. Before I did the MAF conversion I had cat-back exhaust w/ no problems. But I haven't put headers w/ the stock computer so I can't say for sure.
As for the MAF conversion, if you buy the FMS conversion $600(as I did), it comes with a harness that plugs in between the computer and the stock harness. This harness has the plug for the MAF sensor and an overlay harness for the injectors(to convert from multiport to sequential). Maybe 2-3 hours to complete because you have to take off the upper intake manifold to get to the injectors under it.
I find it hard to believe that headers require a reprogram. Before I did the MAF conversion I had cat-back exhaust w/ no problems. But I haven't put headers w/ the stock computer so I can't say for sure.
As for the MAF conversion, if you buy the FMS conversion $600(as I did), it comes with a harness that plugs in between the computer and the stock harness. This harness has the plug for the MAF sensor and an overlay harness for the injectors(to convert from multiport to sequential). Maybe 2-3 hours to complete because you have to take off the upper intake manifold to get to the injectors under it.
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So this FMS conversion to MAF for 600 skins is for a harness. Do you need other hardware or does the OEM hardware from the SD system then just work under a different premise? NOW we're talking about something I might want to do, because by all accounts MAF is much more flexible.
Even so, the mods I am planning for by all accounts would require a re-chipping even for an MAF system: longer duration higher lift cam (540/520) with looser lobe centerline separation (112 to 114), c.i.d. pushed out to 404 with some stroke, Edelbrock Performer heads - these are the high spots.
So if I do these, even with an MAF system I would need a new chip, so I am thinking of doing minor mods now for power (cat back, new filter, hotter plugs, better wires), keep the SD system, install new big nasty motor later, and have a chip burned to spec then and do no further mods (I don't think I would need them - do it right or do it twice!)
Then again, I may be told that this particular motor would be too much for any of it.
Does it even require asking you if the MAF conversion was worth $600?
Even so, the mods I am planning for by all accounts would require a re-chipping even for an MAF system: longer duration higher lift cam (540/520) with looser lobe centerline separation (112 to 114), c.i.d. pushed out to 404 with some stroke, Edelbrock Performer heads - these are the high spots.
So if I do these, even with an MAF system I would need a new chip, so I am thinking of doing minor mods now for power (cat back, new filter, hotter plugs, better wires), keep the SD system, install new big nasty motor later, and have a chip burned to spec then and do no further mods (I don't think I would need them - do it right or do it twice!)
Then again, I may be told that this particular motor would be too much for any of it.
Does it even require asking you if the MAF conversion was worth $600?
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From: Sacramento
the Ford Motor Sport kit, comes w/ the harness, a MAF computer, and a MAF sensor.
What I have done to mine: had a 302 went to a 351 bored .020, 9:1 compression, a FMS cam, don't know the model # or specs off the top of my head. headers, high flow cat, flowmaster muffler, 70mm throttle bodie, MAF conversion, K&N, 24 Lb/hr injectors, 70mm MAF sensor, and I am going to put a bigger fuel pump on (302 pump smaller then 351, I think). I have not done any thing to the stock MAF computer, which by the way is for a 302 (only difference is firing order, changes the wiring harness to the injectors).
What I have done to mine: had a 302 went to a 351 bored .020, 9:1 compression, a FMS cam, don't know the model # or specs off the top of my head. headers, high flow cat, flowmaster muffler, 70mm throttle bodie, MAF conversion, K&N, 24 Lb/hr injectors, 70mm MAF sensor, and I am going to put a bigger fuel pump on (302 pump smaller then 351, I think). I have not done any thing to the stock MAF computer, which by the way is for a 302 (only difference is firing order, changes the wiring harness to the injectors).
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Well dang then! And you have yet to anything to the 'puter?
Sheeeut! Have you ever had it dyno'd? I'm assuming all of this happened in your '89 Bronco, so how does it run?
So where did you get the throttle body, sensor, and the injectors? Were they part of the kit or did you rob them off a Lightning? That's not a whole lot less than what I am going to do, except for the displacement and maybe cam specs. Hmmmm
Sheeeut! Have you ever had it dyno'd? I'm assuming all of this happened in your '89 Bronco, so how does it run?
So where did you get the throttle body, sensor, and the injectors? Were they part of the kit or did you rob them off a Lightning? That's not a whole lot less than what I am going to do, except for the displacement and maybe cam specs. Hmmmm
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ah, shooting my mouth off again, it is a Pro-M 70mm MAF sensor, but it is the BBK 61mm twin throttle body w/ port matched stock upper intake (cool way of saying the stock intake was ground out to match the throttle body).
I'm waiting to get the fuel pump on to have it dyno'd.
w/ 4.56 gears and 33x12.5 tires, it runs great.
the injectors are FMS, bought from Summit racing , the MAF sensor I got direct from Pro-M, and the TB I also got at Summit.
When I get home I'll look up the specs on my cam.
I'm waiting to get the fuel pump on to have it dyno'd.
w/ 4.56 gears and 33x12.5 tires, it runs great.
the injectors are FMS, bought from Summit racing , the MAF sensor I got direct from Pro-M, and the TB I also got at Summit.
When I get home I'll look up the specs on my cam.
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You can use the headers on the 5.8/5.0 EEC-IV without a chip. For true duals, install a bung in the right hand header pipe and plug the O2 sensor into it. The O2 sensor will be only reading the right hand bank, but provided the motor is in decent shape, it will not pose a problem. Also, to free up a little more power, you can re-route the serpentine belt system with a shorter belt to bypass the air-pump. I have done this mod to several trucks now with no problems at all.
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This is going to sound dumb, but what is a bung?
What is the real relativity of the airpump anyway? I'm surprised that bypassing it wouldn't cause a check engine code to pop up. I like that kind of little power-making idea, though. What's the part# on the belt that you use? That's a no-brainer.
How can I be sure that the engine is in good enough shape that a true dual will not spook the computer (besides the obvious)?
Breeze, how do you feel about long-tube headers, high flow cat, and cat back exhaust?
Tell me why this won't work: O2 sensors on both sides of of a true dual system and splice into the sending unit lead so that it reads from both sensors at once?
What is the real relativity of the airpump anyway? I'm surprised that bypassing it wouldn't cause a check engine code to pop up. I like that kind of little power-making idea, though. What's the part# on the belt that you use? That's a no-brainer.
How can I be sure that the engine is in good enough shape that a true dual will not spook the computer (besides the obvious)?
Breeze, how do you feel about long-tube headers, high flow cat, and cat back exhaust?
Tell me why this won't work: O2 sensors on both sides of of a true dual system and splice into the sending unit lead so that it reads from both sensors at once?