High boost FD guys...Help!
10-05-05, 04:44 PM
#1
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High boost FD guys...Help!
Please help me understand a/f adjustments.
When increasing boost from say 10 psi to 15 psi, how do you go about adjusting your a/f ratio to compensate the added levels of air? Can the (stock or stand alone) ecu self adjust all by itself? I understand the limitations of the stock ecu and injectors/pump etc.. but does the PFC or others do this?
Another example to help understand my question.
When you modded FD guys are at the dyno and you take two or three runs and you are increasing boost after each run, do you have to program your a/f ratio before or during the run? Hows it work?
Thanks in advance! D
When increasing boost from say 10 psi to 15 psi, how do you go about adjusting your a/f ratio to compensate the added levels of air? Can the (stock or stand alone) ecu self adjust all by itself? I understand the limitations of the stock ecu and injectors/pump etc.. but does the PFC or others do this?
Another example to help understand my question.
When you modded FD guys are at the dyno and you take two or three runs and you are increasing boost after each run, do you have to program your a/f ratio before or during the run? Hows it work?
Thanks in advance! D
10-05-05, 05:10 PM
#2
Originally Posted by tdazmansFD
Please help me understand a/f adjustments.
When increasing boost from say 10 psi to 15 psi, how do you go about adjusting your a/f ratio to compensate the added levels of air?
When increasing boost from say 10 psi to 15 psi, how do you go about adjusting your a/f ratio to compensate the added levels of air?
Originally Posted by tdazmansFD
Can the (stock or stand alone) ecu self adjust all by itself?
Originally Posted by tdazmansFD
I understand the limitations of the stock ecu and injectors/pump etc.. but does the PFC or others do this?
10-05-05, 05:20 PM
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Say you're at a stoplight and a supercharged Ford Pinto pulls up next to you revving his engine. You're currently running a conservative 10psi. So you decide to turn up the boost to 16 psi (with all of the supporting mods of course) from inside the car. Do you have to mess with your PFC too? Or will your Aftermarket ECU switch maps automatically?
10-05-05, 06:14 PM
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automatically, fuel maps are based on the MAP sensor (amongst other things) -so long as you're tuned for that level of boost and have the requisite supporting mods.
10-05-05, 08:13 PM
#5
Originally Posted by tdazmansFD
Say you're at a stoplight and a supercharged Ford Pinto pulls up next to you revving his engine. You're currently running a conservative 10psi. So you decide to turn up the boost to 16 psi (with all of the supporting mods of course) from inside the car. Do you have to mess with your PFC too? Or will your Aftermarket ECU switch maps automatically?
10-05-05, 08:28 PM
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tdazmansFD I have the Peter Farrell piggyback computer. It has a **** in the glove box for setting 1, stock for emissions testing, 2, 12lbs for pump gas, and 3, for race gas, as much boost as the car will make, 17 or 18. Turn the **** & you change your ignition, fuel, and boost map.
Setting two and three involved having a tuner put the car on the dyno to work up the maps.
The Farrell computer came with three pre-set maps but getting the maps reworked for your specifc car is the way to go.
The PFS units are pretty cheap used and so long as you stick with the twins and don't use a midpipe, is tuneable and does all you need for a fast street car.
Setting two and three involved having a tuner put the car on the dyno to work up the maps.
The Farrell computer came with three pre-set maps but getting the maps reworked for your specifc car is the way to go.
The PFS units are pretty cheap used and so long as you stick with the twins and don't use a midpipe, is tuneable and does all you need for a fast street car.
10-05-05, 10:15 PM
#7
The Laser Man
Another way to see how your car is running with high boost is to get a wide band Fuel/Air ratio guage and see it for yourself~~~ not the crapy Fuel/Air ratio guages.... get a real wide band... it maybe a little pricy but that is as accurate you will ever get. 
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10-05-05, 11:57 PM
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Duty cycle refers to the percentage that something (solenoid, injector, etc) operates. A 100% duty cycle indicates that a part is operating at full capacity.
10-06-05, 12:05 AM
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So if you increased your fuel pressure would that mess with the duty cycle? Or is that something that the ecu controls. If it is ecu controlled only, would you increase fuel use just by increasing pressure.
10-06-05, 12:15 AM
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Originally Posted by tdazmansFD
So if you increased your fuel pressure would that mess with the duty cycle? Or is that something that the ecu controls. If it is ecu controlled only, would you increase fuel use just by increasing pressure.
Conversely, you could run lower injector duty cycles and higher fuel pressure and achieve the same total amount of fuel injected. However, most fuel pumps start crapping out at higher pressures (higher boost levels).
10-06-05, 01:07 AM
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Originally Posted by Mahjik
You get "tuned" to run the 16 PSI, but you have your boost controller turned down to run 10 until you need it. You don't need to reprogram to run the lower boost setting.
unless your running 2 different types of petrol correct?..say 16psi on 93 oct and for 20psi on a 50/50 mix of 93+c16 or just straight c16...you would need 2 maps wouldnt you
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