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nismo2491
03-26-2004, 04:45 PM
Has anybody ever done a fuel pump rewire on a 240sx? I come from DSM's and that is a cheap mod to increase fuel flow. basically you rewire the wiring to the fuel pump with thicker gauge wire and a heavier relay in order to get a full 13v to the pump. I am installing a 255lph walbro and want to know if this would be a good thing or is the 240sx wiring more than adaquate.
KEvin
nightwalker
03-26-2004, 05:31 PM
as far as I know, the walbro will be more than adequate up to 500 hp. Don't see any reason to increase the voltage. I'm not too sure of the wiring, and relay idea though. I'm almost 100% sure you won't need to do it with the walbro.
nismo2491
03-26-2004, 07:57 PM
it doesn't actually increase the voltage per se. it just makes sure the pump sees full voltage rather than resistance causing lower voltage. DSM's have been measured to be as low as 10 volts at the pump and jump to 13 volts after the rewire.
KEvin
PSI240SX
03-27-2004, 10:02 AM
as far as I know, the walbro will be more than adequate up to 500 hp. Don't see any reason to increase the voltage. I'm not too sure of the wiring, and relay idea though. I'm almost 100% sure you won't need to do it with the walbro.

Actually...... My friend has that pump in his car and it started leaning out at 370hp. He was told by the tuner to rewire the pump with larger guage wire and see what happens. He is at the dyno today with the new wiring so I will know if it really helped or not. The tuner told him to rewire, and bring another fuel pump just incase. He has seen plenty of walbro's just not flow as much as others do. I will post actual results later today when I know more.
PSI240SX
03-27-2004, 10:34 AM
***Real World Update***

The rewiring of the fuel pump solved the problem! Went back to the dyno and made 382rwhp with perfect A/F ratio's right accross the board.

Consider this case closed.
nismo2491
03-27-2004, 10:52 AM
alright. 380whp is decently close to the 420 or so I should be putting down so after rewire hopefully I'll be alright.
KEvin
West
03-27-2004, 11:17 AM
I did this forever ago. I was NA with bolt ons at the time so there was no real benifit other then the anoying wine that resulted from the rewire.