I thought this might be of interest to those anticipating a fuel pump change. I just made some changes to my nitrous system that may be of interest. i previously was spraying a 350 shot on an engine with 500 NA hp. I installed a 255 lph Walbro in place of the oem pump and used a voltage booster on the pump. When spraying a 200 shot there were no fuel pressure issues. When I changed from my 200 shot to the 350 shot the fuel pump would have huge deviations in pressure as each stage of nitrous came in. the second stage especially would send the fuel pressure oscillating wildly. i would see swings from 50 to 35 psi and they would stay dynamic never settling to one presssure point
I was getting ready to go the external fuel pump route. I tried one last thing and I was glad i did. I installed a fuel pressure damper in front of the two fuel solenoids. I ran this weekend and was straying 275 hp (jets)with an new NA rating of 525, therefore, putting out approxiamtely 800 hp. The fuel pressure ran a very solid 49 psi with little if any deviations, even when the solenoids were pulsed for progressive operation. This demonstrates you can run an NA or nitrous car with an almost stock intank pump all the way up to 800 hp.
For those that want to fine tune their nitrous system, I was putting down similar hp even though I previously sprayed 350 versus the 275 this year. The difference was a double insulated 6AB nitrous line. I ran the the whole length from the tank to the solenoids in the double insulated line. I also ran the line inside a reflective tube. In affect, the engine now gets all cool liquid nitrous, no more partial gas. Another side benefit was that engine did not go super rich as the rpms increased. It was basically a flat air fuel curve with no VEC addition/reduction past 3500 rpm's.
I was getting ready to go the external fuel pump route. I tried one last thing and I was glad i did. I installed a fuel pressure damper in front of the two fuel solenoids. I ran this weekend and was straying 275 hp (jets)with an new NA rating of 525, therefore, putting out approxiamtely 800 hp. The fuel pressure ran a very solid 49 psi with little if any deviations, even when the solenoids were pulsed for progressive operation. This demonstrates you can run an NA or nitrous car with an almost stock intank pump all the way up to 800 hp.
For those that want to fine tune their nitrous system, I was putting down similar hp even though I previously sprayed 350 versus the 275 this year. The difference was a double insulated 6AB nitrous line. I ran the the whole length from the tank to the solenoids in the double insulated line. I also ran the line inside a reflective tube. In affect, the engine now gets all cool liquid nitrous, no more partial gas. Another side benefit was that engine did not go super rich as the rpms increased. It was basically a flat air fuel curve with no VEC addition/reduction past 3500 rpm's.
