fuel flow questions
02-04-2008, 09:49 PM
#1
Rainman
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fuel flow questions
i did a quick search but...
would the stock 8v fuel rail be adequate to flow with a 3-3.5BAR FPR?
also, with 3.5 BAR about 50PSI, would it make sense to be using injectors of between 40-50 lb/hr flow? or is it more complicated than that?
also, what is the flow rate of the stock fuel pump?
thanks
would the stock 8v fuel rail be adequate to flow with a 3-3.5BAR FPR?
also, with 3.5 BAR about 50PSI, would it make sense to be using injectors of between 40-50 lb/hr flow? or is it more complicated than that?
also, what is the flow rate of the stock fuel pump?
thanks
02-04-2008, 10:01 PM
#2
Race Director
I don't know if there is a 3 bar fpr that will bolt on to the early 944 fuel rail. I'm sure it can "flow" a 3 bar fpr (common upgrade on 951s)
injector flow rate is based on a set pressure, they will flow more at a higher pressure
stock fuel pump is same as 951 irrc. no matter what fuel pump you have the fpr will regulate how much your gettting
injector flow rate is based on a set pressure, they will flow more at a higher pressure
stock fuel pump is same as 951 irrc. no matter what fuel pump you have the fpr will regulate how much your gettting
02-04-2008, 10:24 PM
#3
Rainman
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im planning out a full supercharger build with a goal of 300 crank hp. based on research on the 944 engine, the blower i will use, and some other people's testimonies along with my own math, 36 lb/hr injectors at full duty cycle with airflow that is enough to maintain a stoichimetric af ratio of 14.7:1, that should be about 300HP. thats only theoretically and not accounting for friction etc.
thats why im looking a little bigger. would a 3BAR FPR be able to feed a 42 lb/hr injector?
thats why im looking a little bigger. would a 3BAR FPR be able to feed a 42 lb/hr injector?
02-05-2008, 02:51 AM
#4
Burning Brakes
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im planning out a full supercharger build with a goal of 300 crank hp. based on research on the 944 engine, the blower i will use, and some other people's testimonies along with my own math, 36 lb/hr injectors at full duty cycle with airflow that is enough to maintain a stoichimetric af ratio of 14.7:1, that should be about 300HP. thats only theoretically and not accounting for friction etc.
02-05-2008, 04:19 PM
#6
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im planning out a full supercharger build with a goal of 300 crank hp. based on research on the 944 engine, the blower i will use, and some other people's testimonies along with my own math, 36 lb/hr injectors at full duty cycle with airflow that is enough to maintain a stoichimetric af ratio of 14.7:1, that should be about 300HP. thats only theoretically and not accounting for friction etc.
thats why im looking a little bigger. would a 3BAR FPR be able to feed a 42 lb/hr injector?
thats why im looking a little bigger. would a 3BAR FPR be able to feed a 42 lb/hr injector?
The question you should have, if you're going to have one, is can the stock fuel pump keep up with the fuel flow requirements of a 42lb injector @ 3 bar? The stock rail will and most injectors are rated at 3.0 bar of fuel pressure. 42lb injectors would be fine for this application but 951 injectors @ 3.0 bar would work as well. The stock fuel rail and fuel lines are just fine for these moderate HP levels.
Last edited by Jeremy Himsel; 02-05-2008 at 04:46 PM.
02-05-2008, 10:25 PM
#7
Rainman
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I think you're confusing things a bit. The FPR regulates fuel rail pressure by restricting outobund flow back to the tank. Also, at full load with a supercharged engine you'll want to be in the 12.0:1 to 12.5:1 range depending on conditions/boost/compresion/timing. 14.7:1 should be for idle and crusing throttle positions only. You should determine what the max airflow will be to determine what HP you anticipate, and then determine injector size from that.
The question you should have, if you're going to have one, is can the stock fuel pump keep up with the fuel flow requirements of a 42lb injector @ 3 bar? The stock rail will and most injectors are rated at 3.0 bar of fuel pressure. 42lb injectors would be fine for this application but 951 injectors @ 3.0 bar would work as well. The stock fuel rail and fuel lines are just fine for these moderate HP levels.
The question you should have, if you're going to have one, is can the stock fuel pump keep up with the fuel flow requirements of a 42lb injector @ 3 bar? The stock rail will and most injectors are rated at 3.0 bar of fuel pressure. 42lb injectors would be fine for this application but 951 injectors @ 3.0 bar would work as well. The stock fuel rail and fuel lines are just fine for these moderate HP levels.
thats exactly what i needed to know but couldnt phrase it right.
