what would happen if i just installed a Walbro 255 pump into the stock location. i have heard that a few CN guys just run an inline fuel pump without a return. Now, because of the larger fuel pump, will the fuel pressure raise, or will it stay @ 50psi? Also, if the fuel pressure stays @ 50psi, and i have a larger fuel pump and i can flow more fuel why should i even care about running a return line?? I don't understand why I would go with an aftermarket FPR if a pump can flow more @ lower PSI's. I understand that your fuel persure needs to be higher then your boost for the injector to fire fuel into the intake. But the only gain I see is to set your FPR @ 35psi and tune your car their. But when the car goes into boost it will see (35psi(base)+10psi(vac)+15psi(boost)=60psi, and your new setup would flow less then a 50psi setup. Do you see my ponit?
http://www.autoperformanceengi....html Goto where it says intank technical.




Modified by ares650 at 8:32 PM 9/11/2005

 

any input!!

 

bump

 

OK....I swaped in the pump this weekend for the most part it was a stright up swap, three very small mods. I used the WAL-GSS342(stamped on the side of the pump), I also used the stock FPR and no return line. The pump did raise the stock idle fuel presure from 50 psi to 57psi but after 4300rpm it went back to 50psi. At 10-12psi of boost I had to lean the car out about 12-14% to hold 11.7 a/f's. That should show that the stock fuel pump was not keeping up to the flow.