Originally posted by OhSigmaChi:
SO your system is a kind of home grown version made of various manufacturers components. Why do you say go through the fuel rail? what is so bad about the extra fuel line and pump? What are you using as far as ignition timing control?
Yup. The system is a mut. No timing control with this shot, just 1 step colder plugs @ .035 gap. The pump: I first tried a cheap 30 gph, 7 psi, diaphram pump (bad because it pulsates). On the dyno, I was lean in the low rpm range (torque peak) but fine in the upper revs. Assuming this may be a supply problem during peak torque load, I stepped up the the larger Holley 110 gph pump that produces 14 psi with the regualator wide open. On the dyno again and same problem, lean in the lower range. Next for a test, I hit the nitrous at higher rpm and it was lean there. So I dont think it is a supply problem, but a pressure problem. The fuel rail operates on a much higher pressure than those pumps can produce (without spending MUCHO money). With the pump, when the solenoids opened I think it was that the nitrous @ 1000 psi, was beating the fuel to the jets (14 psi) by a split second, pretty much giving me a dry shot to start with. Also, I think a factor is the rail will be right there, the fuel wont have to travel the full length of the car to hit the jets. I'll soon find out if going thru the rail will cure my problems. Hitting the dyno for the 3rd week straight next week....
Regardless, looks like I may be attacking a return style fuel system very soon.
