Walbro Fuel Pump ?
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Le Mans Master
Joined: Apr 2001
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From: Little Elm TX
Walbro Fuel Pump ?
Can anyone answer a quick question? What’s the difference between the Walbro 307 and the Walbro 340? They both flow 255 LPH. I’m thinking it’s the max pressure but I’m not sure. I ordered a 340 and I think I’ve got a 307.
Le Mans Master
Joined: Oct 1999
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From: Sachse Texas
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Re: Walbro Fuel Pump ? (R94 LT 1)
No difference until you go over 55psi of fuel pressure. Up to that point they flow identically. If you are sticking with naturally aspirated or nitrous P/A, then you can just get the 307. The 340 is better suited for the blower or turbo setups that increase fuel pressure with boost levels.
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 7,411
Likes: 253
From: Little Elm TX
Re: Walbro Fuel Pump ? (Vette92)
No difference until you go over 55psi of fuel pressure. Up to that point they flow identically. If you are sticking with naturally aspirated or nitrous P/A, then you can just get the 307. The 340 is better suited for the blower or turbo setups that increase fuel pressure with boost levels.
The only things I "might" do in the future are better heads, cam, 398, and nitrous. Like you, I plan on running a seperate pump for the wet system if I run nitrous, so there's no need for a 340 here?
Le Mans Master
Joined: Oct 1999
Posts: 9,713
Likes: 3
From: Sachse Texas
Cruise-In I Veteran
Cruise-In II Veteran
Re: Walbro Fuel Pump ? (ld85)
ld85, there is a big difference in how the two pumps flow beginning at 55psi.
Here is a graphic example:
http://www.vfaq.com/pump-Walbros.html
(Blue line versus red line shows the comparison between the standard and high flow pumps.)
Chris
[Modified by Vette92, 2:10 PM 4/22/2003]
Here is a graphic example:
http://www.vfaq.com/pump-Walbros.html
(Blue line versus red line shows the comparison between the standard and high flow pumps.)
Chris
[Modified by Vette92, 2:10 PM 4/22/2003]
Race Director
Joined: Feb 1999
Posts: 12,772
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From: Indianapolis IN
Re: Walbro Fuel Pump ? (Vette92)
My post is just the info from this website. BTW, I was told that anything above 60-psi was not recommended for my 24# injectors by Rich at Cruzin Performance.
http://www.precisionte.com/
http://www.precisionte.com/
Drifting
Joined: Aug 2000
Posts: 1,521
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From: West Islip New York
Re: Walbro Fuel Pump ? (R94 LT 1)
One of the biggest differences is that the 340 has an armature made by Walbro which is more efficient and uses less current than the 307. The 307 draws more current and has a lower rated check valve which you can see as the volume drops off over 50 psi.
Under 50 psi both pumps work identically. I went with the 340 because of the better armature.
Under 50 psi both pumps work identically. I went with the 340 because of the better armature.
