Fuel Managemnt When Boosting
12-21-2004, 02:25 PM
#1
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Fuel Managemnt When Boosting I'm looking to twin turbo a LR4 4.8L Truck motor at a conservative 5-7 psi, and have some EFI related questions.
When boost starts to come on, does the MAF provide enough signal for the proper addition of fuel per unit of air? Draw through or pressure side of turbo for the MAF? I see that companies such as STS provide a FMU to increase fuel pressure with their system. Would this also be necessary for my setup, or would it be better to go to higher rated injectors sans the FMU. There is a large selection of devices for boosted applications, so I just want a measure for just how much is necessary to work with my boost levels. It would of course be nice to add or change the fewest things possible, and yet achieve the best or adequate results.
Thanks,
Andy1
When boost starts to come on, does the MAF provide enough signal for the proper addition of fuel per unit of air? Draw through or pressure side of turbo for the MAF? I see that companies such as STS provide a FMU to increase fuel pressure with their system. Would this also be necessary for my setup, or would it be better to go to higher rated injectors sans the FMU. There is a large selection of devices for boosted applications, so I just want a measure for just how much is necessary to work with my boost levels. It would of course be nice to add or change the fewest things possible, and yet achieve the best or adequate results.
Thanks,
Andy1
12-21-2004, 03:54 PM
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The stock MAF is capable of reading ~580flywheel hp in absolute stock form. I think you should be fine allowing the MAF to control fueling at the levels a 4.8L with 5-7psi will put out.
The Draw through or Pull through subject has been discussed alot in the Forced Induction. You might want to search around a little bit in there. Each has its pros and cons but, either way will work. With twin turbos the pressure side for the MAF would probably be the easiest way.
Don't put a FMU on if you don't have to. The way to go is to put bigger injectors in capable of supplying enough fuel and reprogram for them.
Hope that helps.
The Draw through or Pull through subject has been discussed alot in the Forced Induction. You might want to search around a little bit in there. Each has its pros and cons but, either way will work. With twin turbos the pressure side for the MAF would probably be the easiest way.
Don't put a FMU on if you don't have to. The way to go is to put bigger injectors in capable of supplying enough fuel and reprogram for them.
Hope that helps.