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Found this and thought it would help people wanting bigger injectors and know what size it better for a desired BHP
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Injector Sizes and BHP limits
06/01/2006
Remember that the stock fuel pressur regulator will raise fuel pressure in a 1:1 ratio with the boost. For every psi of boost above ambient pressure the FPR will add 1 psi of fuel pressure.
If you are running 14psi of boost, your fuel pressure at WOT (wide open throttle) will be 43.5 + 14psi = 57.5psi. This is why you should not raise your base WOT fuel pressure above 4 bar. @ 4bar base fuel pressure and 14psi you will be running 58psi + 14psi = 72psi of fuel pressure @ WOT. This is why its important to find the right sized injector. I garuntee any stock rubber hose will be a bit stressed at this pressure and your fuel pump will be hard pressed to keep that pressure. Also your injectors may stick because the valve cant over come that high a fuel pressure.
444cc @ 3bar @ 85% @ 0.5BSFC = 287bhp
444cc @ 3bar @ 100% @ 0.5BSFC = 338bhp
555cc @ 3bar @ 85% @ 0.5BSFC = 359bhp
555cc @ 3bar @ 100% @ 0.5BSFC = 422bhp
600cc @ 3bar @ 85% @ 0.5BSFC = 388bhp
600cc @ 3bar @ 85% @ 0.5BSFC = 457bhp
700cc @ 3bar @ 85% @ 0.5BSFC = 453bhp
700cc @ 3bar @ 100% @ 0.5BSFC = 533bhp
1000cc @ 3bar @ 85% @ 0.5BSFC = 647bhp
1000cc @ 3bar @ 100% @ 0.5BSFC = 761bhp
DO NOT RAISE BASE WOT FUEL PRESSURE PAST 4BAR
444cc @ 4bar (513cc) @ 85% @ 0.5BSFC = 332bhp
444cc @ 4bar (513cc) @ 100% @ 0.5BSFC = 390bhp
555cc @ 4bar (642cc) @ 85% @ 0.5BSFC = 415bhp
555cc @ 4bar (642cc) @ 100% @ 0.5BSFC = 489bhp
600cc @ 4bar (694cc) @ 85% @ 0.5BSFC = 449bhp
600cc @ 4bar (694cc) @ 100% @ 0.5BSFC = 528bhp
700cc @ 4bar (810cc) @ 85% @ 0.5BSFC = 524bhp
700cc @ 4bar (810cc) @ 100% @ 0.5BSFC = 617bhp
1000cc @ 4bar (1157cc) @ 85% @ 0.5BSFC = 749bhp
1000cc @ 4bar (1157cc) @ 85% @ 0.5BSFC = 881bhp
Quick Login
<< Go Back
Injector Sizes and BHP limits
06/01/2006
Remember that the stock fuel pressur regulator will raise fuel pressure in a 1:1 ratio with the boost. For every psi of boost above ambient pressure the FPR will add 1 psi of fuel pressure.
If you are running 14psi of boost, your fuel pressure at WOT (wide open throttle) will be 43.5 + 14psi = 57.5psi. This is why you should not raise your base WOT fuel pressure above 4 bar. @ 4bar base fuel pressure and 14psi you will be running 58psi + 14psi = 72psi of fuel pressure @ WOT. This is why its important to find the right sized injector. I garuntee any stock rubber hose will be a bit stressed at this pressure and your fuel pump will be hard pressed to keep that pressure. Also your injectors may stick because the valve cant over come that high a fuel pressure.
444cc @ 3bar @ 85% @ 0.5BSFC = 287bhp
444cc @ 3bar @ 100% @ 0.5BSFC = 338bhp
555cc @ 3bar @ 85% @ 0.5BSFC = 359bhp
555cc @ 3bar @ 100% @ 0.5BSFC = 422bhp
600cc @ 3bar @ 85% @ 0.5BSFC = 388bhp
600cc @ 3bar @ 85% @ 0.5BSFC = 457bhp
700cc @ 3bar @ 85% @ 0.5BSFC = 453bhp
700cc @ 3bar @ 100% @ 0.5BSFC = 533bhp
1000cc @ 3bar @ 85% @ 0.5BSFC = 647bhp
1000cc @ 3bar @ 100% @ 0.5BSFC = 761bhp
DO NOT RAISE BASE WOT FUEL PRESSURE PAST 4BAR
444cc @ 4bar (513cc) @ 85% @ 0.5BSFC = 332bhp
444cc @ 4bar (513cc) @ 100% @ 0.5BSFC = 390bhp
555cc @ 4bar (642cc) @ 85% @ 0.5BSFC = 415bhp
555cc @ 4bar (642cc) @ 100% @ 0.5BSFC = 489bhp
600cc @ 4bar (694cc) @ 85% @ 0.5BSFC = 449bhp
600cc @ 4bar (694cc) @ 100% @ 0.5BSFC = 528bhp
700cc @ 4bar (810cc) @ 85% @ 0.5BSFC = 524bhp
700cc @ 4bar (810cc) @ 100% @ 0.5BSFC = 617bhp
1000cc @ 4bar (1157cc) @ 85% @ 0.5BSFC = 749bhp
1000cc @ 4bar (1157cc) @ 85% @ 0.5BSFC = 881bhp