sick-1

Ok i have 95z 383 heads/cam with tnt 150 shot. Installed walbro 255 36lb injectors. ON the dyno the car would run pretty lean on the n20. Car made 550rwhp on spray. I dont currently have a fuel pressure reg or gauge so not sure what the fuel pressure was. My question is do you think that a racetronix plug and play would be sufficant in feeding the n20 or will i need more pump/ fuel rail modification? I plan on adding the gauge/ reg soon so any suggestions on what to get would help. Thanks.

Injuneer

Just playing with numbers, converting back to flywheel HP, and assuming a BSFC of 0.55 #/HR/HP, and allowing for a 10% return to the tank at max engine load, the 255 LPH pump is marginal. I get 266 LPH required - but it took a lot of ASSumptions to reach that number. With a good voltage supply, the pump might meet that requirement. With a poor voltage supply its not going to keep up.

Install the gauge.

sick-1

Do you think running my fuel rails/lines parallel would help this problem any? I have read about some guys doing that and it makes sense, but i am just not sure if i am making enough power to worry about that.

Injuneer

Running the rails in parallel isn't going to make much of a difference in overall system pressure, if the pump can't keep up with the demand. The main advantage of running them in parallel is to reduce the pressure variation between the first and last cylinders in the system.... with them running in series, with a very high fuel demand, and a stock configuration, #8 is going to be at a higher pressure than #7. Running the rails in parallel reduces that variation by about 1/2.

You need to check the fuel pressure at max engine load. Pump may be OK, may not be.