How fast with a double pumper ?

[chasmat2316]

How fast can you go on a double pumper with -8 feed, -6 return, dual feeding an alu rail before having a lean out problem? At what speed should you look to go external? This is for a street car that get's alot of miles? thanx

 

[750H.P.V6]

You can run 9's with stock fuel lines and fuel rail if that helps.

Neal

 

[steve hughes]

I've ran 9.27 with a homemade double pumper with 2 340 walbros, -8 feed, -6 return, 95# injectors champion intake with alumunum fuel rail single feed to the rail. I have also ran 9.55 with a stock intake and stock fuel rail single feed also but with 160# injectors. I'm useing a metco spare tire well fuel cell.

 

[chasmat2316]

You can run 9's with stock fuel lines and fuel rail if that helps.

Neal

yes I plan to dual feed my champion rail with -8 & run a -6 return . I plan on making a 1/2" pick up right off the double pumper. I'm hoping to get into the mid 130's with my new combo & planning the fuel system mods. My second choice was to run an external with a bulk head @ the baffle in the tank? I'm thinking dual feeding the rail with -8 feed & -6 return should be enough?

 

[chasmat2316]

I've ran 9.27 with a homemade double pumper with 2 340 walbros, -8 feed, -6 return, 95# injectors champion intake with alumunum fuel rail single feed to the rail. I have also ran 9.55 with a stock intake and stock fuel rail single feed also but with 160# injectors. I'm useing a metco spare tire well fuel cell.

Steve did you run one pump on a hobbs switch or the two full time? thanx to all for any info!

 

[chasmat2316]

looking for all info!

 

[turbofabricator]

If you run both full time, you will need to step up to a big aftermarket regulator to bleed off the pressure. Stock adjustable (including accufab) only have a tiny orafice, and will not be able to bleed off the extra volume. You can fab up a adaptor to plug into the stock fuel rail to run external. It looks like this: http://www.turbobuick.com/forums/general-turbo-buick-tech/240060-revised-regulator-fitting.html You can also build one of these, too. http://www.turbobuick.com/forums/general-turbo-buick-tech/215155-new-double-pumper-sending-unit.html

 

[steve hughes]

I originally ran the second pump off of a micro switch at wot. I later changed it to run both pumps all the time. I have no problem controlling fuel pressure with an accufab regulator that has not been moddified. I also run both pumps thru the stock pickup. Believe it or not but it works fine for me. If i have one pump running and turn the second on at idle fuel pressure jumps 2 psi at most. With stock lines itwould jmp 10 psi.

 

[Scott Atk]

Same here. No problem running two pumps full time through an Accufab regulator. My idle fuel pressure is 38 psi.

 

[d90dan]

I ran out of fuel somewhere in the 135-137mph range. Doublepumper, stock lines/rail, with 75lb injectors at 80% duty cycle.