Aftermarket FPR on NA?

NoDOHC · 12-17-2010, 01:05 AM

ReTED is right, lowering the fuel pressure hurts the atomization.

I ran for about two years with banjo bolt mod.

I was only listing the reasons that someone would install an aftermarket FPR on a NA FC.

I had no fuel pressure issues on the dyno @ 216 WHp. Bone stock 460 cc/min injectors (63% duty cycle), Stock FPR (Turbo-style), stock fuel pump.

I think that you could get about 300WHp out of the 460 cc/min injectors using peak and hold (90% Duty cycle). The stock fuel pump should be able to handle that. (This assumes an NA build, it appears that Turbo engines are hard pressed to make 200 WHp on 550 cc/min injectors). Chances are, unless you know a lot about porting, you will not make anywhere near 300WHp.

The S5 fuel rail has a much better pulsation damper than the S4 fuel rail.

The FPR is on the secondary fuel rail.

12-17-2010, 01:05 AM	#13
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	ReTED is right, lowering the fuel pressure hurts the atomization. I ran for about two years with banjo bolt mod. I was only listing the reasons that someone would install an aftermarket FPR on a NA FC. I had no fuel pressure issues on the dyno @ 216 WHp. Bone stock 460 cc/min injectors (63% duty cycle), Stock FPR (Turbo-style), stock fuel pump. I think that you could get about 300WHp out of the 460 cc/min injectors using peak and hold (90% Duty cycle). The stock fuel pump should be able to handle that. (This assumes an NA build, it appears that Turbo engines are hard pressed to make 200 WHp on 550 cc/min injectors). Chances are, unless you know a lot about porting, you will not make anywhere near 300WHp. The S5 fuel rail has a much better pulsation damper than the S4 fuel rail. The FPR is on the secondary fuel rail. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)