TBIThrottle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.
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getting a mild build: vortec heads, intake, mild 298/298 duration cam. with the 5.7 injectors, which pump should I get? Is the 305 tpi pump enough, or do I need a walbro 190?
I would recommend a Walbro 190lph pump. This pump at TBI fuel pressure can support ~450hp and you will have no prob getting the fuel pressure down like you would have if you threw a 255lph pump in your tank. (assuming your running around the stock fuel pressure) If you plan on bumping the FP up to upwards of 20psi+ then I would suggest a 255lph.
Doesn't the tbi have a return style FP setup? I always thought that the regulator cut it off at the predetermined PSI and just returned the excess to the tank. I could be wrong though.
Doesn't the tbi have a return style FP setup? I always thought that the regulator cut it off at the predetermined PSI and just returned the excess to the tank. I could be wrong though.
That is true. However the return line for the TBI setup is designed for the stock pump flowing ~13 psi. With a 255lph pump in the tank so much fuel is being deferred to the return line that it cant keep up with the pump, raising the overall fuel pressure of the system. In short, the return line is too small for the 255lph pump at stock fuel pressure.
