Low numbers on Supercharger
Joined: Sep 2003
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From: New Jersey
Originally Posted by JustinC,Feb 11 2008, 11:53 AM
Wait a second. The normal ESM controls timing and acts as a map clamp and uses teh FPR to push more pressure so that when the injectors open there is more fuel coming out.
I was under the impression that if you use a larger fuel pump and an EMU that can control the injector duty directly, that you don't need the FPR b/c you can accurately meter more fuel.
The injector can only flow so much fuel whether the pressure is higher or not, the nozzle is only so big, so I don't see how it can make a difference whether the pressure is higher vs the injector metering the correct amount of fuel.
I was under the impression that if you use a larger fuel pump and an EMU that can control the injector duty directly, that you don't need the FPR b/c you can accurately meter more fuel.
The injector can only flow so much fuel whether the pressure is higher or not, the nozzle is only so big, so I don't see how it can make a difference whether the pressure is higher vs the injector metering the correct amount of fuel.
Yes teh EMU can control the injector duty but it can't make them flow anymore then they can handle, larger fuel pump or not. Thats why it also comes with a FPR.
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From: Raleigh, NC
Originally Posted by JustinC,Feb 11 2008, 11:53 AM
I was under the impression that if you use a larger fuel pump and an EMU that can control the injector duty directly, that you don't need the FPR b/c you can accurately meter more fuel.
Installing just a fuel pump and the EMU would be great for an NA tune, but terrible for a boosted scenario without larger injectors.
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From: Selma, TX
Originally Posted by deathsled,Feb 11 2008, 12:08 PM
I think in general when injector flow rates are quoted they are for a normal base pressure of 46 or 47psi
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From: Mesa
I ran the stock injectors on OEM fuel pump and no FPR to 320 whp at 6.8 psi with an emanage ULT. The injectors were at 95% DC from 8k to 9k, but there is some headroom. Now running larger squirters.
I am guessing that your tuner is pulling tons of timing. Have they had experience with the EMU? I saw an EMS tuner fill in an eManage map with the values he would typically put in the EMS timing map as he did not realize the the ULT maps pulls additional timing where the EMS you set the actual timing. Values should be 0 to -10 or -13, you probably have values like -40 in there.
I am guessing that your tuner is pulling tons of timing. Have they had experience with the EMU? I saw an EMS tuner fill in an eManage map with the values he would typically put in the EMS timing map as he did not realize the the ULT maps pulls additional timing where the EMS you set the actual timing. Values should be 0 to -10 or -13, you probably have values like -40 in there.
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From: Raleigh, NC
generally running injectors over 80% IDC is frowned upon, and in most cars high IDCs like 90% will cause the factory ECU to significantly retard timing. The s2000 may not work this way however.