Need help with Fuel PSI dropping under boost.
Need help with Fuel PSI dropping under boost. Like the title says I have a drop in fuel preasure under boost. I have a GMR fuel system the system has 2 340 gph Walbro pumps in take. No hot wire kit. Under boost the fuel presure drops to 50 amd stays there. Should I be concearnd? I wouldn't think I should have any fuel presure drop with the amount of pump I have.
Joined: Jun 2004
Posts: 1,501
Likes: 7
From: Ft. Irwin, California (But Virginia is home)
Yes, I was having similiar probs but with only 5lbs of boost on my turbo. I converted to a return style fuel system and added a boost-referenced FPR. Now I have 63PSI at WOT and high RPM. The boost referenced FPR adds one pound of pressure for each lb of boost. The prob is the injectors are fighting against the boost pressure to deliver the fuel.
Also, at your HP level, you might want to consider running a larger feed line, like an 8AN or so to deliver more volume of fuel.
If you have Q's on the FPR and eturn style system, use the search. I have pics of one I installed and commentary on it in this section.
Also, at your HP level, you might want to consider running a larger feed line, like an 8AN or so to deliver more volume of fuel.
If you have Q's on the FPR and eturn style system, use the search. I have pics of one I installed and commentary on it in this section.
Bigger lines are going to be pointless unless you have bigger rails. If your serious and want to make serious power. I would go ahead and upgrade to an inline fuel pump. Aeromotive, weldon, etc etc.. Those 340s should be alright until low 600s.
