Quote:
Originally Posted by NAPA 68
For those who utilized and LSA from a production car (versus crate), did you utilize the OE PCM and thus the PWM control for the fuel pump?
I am planning out what I would need to do if I bought a takeout LSA, and tried to use as many OE components as possible (opposed to say a Vapor Worx).
In advance, thanks.
Tim
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I've used OEM FSCM (Fuel System Control Module) to control fuel pump in several builds.
Advantage: Vs VaporWorx is feedback of actual line pressure (which is then used for pulse-width calculations based on delta-P across injectors). So more accurate for fuel delivery.
Disadvantage: Carl can put together system with more capability - stock FSCM is current limited so can only handle so much electrical power which limits fuel flow capability. Since flow rate of injector change is square root of delta-P, even slight variation of actual pressure is not overly significant - especially for most applications not concerned about production level emission requirements.
Stock systems have various executions:
LSA CTS-V is PWM until commanded to 450 kPa - then runs straight voltage to pumps (there are 2 in CTS-V fuel pump module) due to current limitations of FSCM. Fuel pressure is then regulated by internal fuel pressure regulator in fuel pump sending unit.
LSA Camaro ZL1 is PWM over entire range of pressure control. Single pump in fuel sending unit. Commanded pressures same as CTS-V (250-450 kPa)
LS9 Corvette is PWM over entire range - but also adds 3-phase pump control module since pump is 3-phase. Also runs to higher fuel pressures than either LSA (250-600 kPa). This is primary reason anyone wanting to install LS9 into hot-rod needs larger injectors as controlling to 600 kPa (~90 psig) is very difficult - if you want to keep fuel pump temps and fuel temps in check.
Carl has done a wonderful job in executing a robust solution for controlling multiple pumps to cover broad range of fuel flow requirements on returnless system. I use VaporWorx exclusively now due to the simplicity, robustness
and reliability of PWM control over entire range of engine operation. Never thought controlling from 600 rpm idle on gas to 1200+ hp on E85 with same system could perform so flawlessly!
Dave