neit_jnf

iTrader: (17)

I got a walbro hp 255 pump for my fd. I searched and read all I could find in all the threads about the different pumps and dual pump setups but I couldn't find someone that did this.

I saw dual walbros, dual supras, etc but why ditch the stock pump instead of keeping it there along with the single walbro?

I would Y the outlet of the pumps and wire them in parallel with a higher amp relay/fuse...

Good or Bad idea?? I'm with stock twins and stock injectors, planning on bigger secondaries in the not too near future. I figured while I'm in there why not do this? Or is the single walbro enough?

kuroi FD

Yeah i though about this too, or dual stockers. I think the problem is they flow different pressures and that may have something to do with it.

DaleClark

iTrader: (55)

I'm not a fan of dual pump setups, as you're doubling failure points pretty bigtime. I would start simple - run the Walbro, and if you're getting a fuel pressure drop, go from there. You definitely need a fuel pressure gauge if you're going to be messing with that stuff!

Dale

rotorbrain

i agree with dale on this one. if youre worried about an injector not getting enough fuel. . . reroute the fuel rails. . . there are ways to get around some of these things w/o going w/2 pumps.

dubulup

single

manatecu

iTrader: (6)

I have had two walboro pumps for about 1 year. I have only had one problem. One of the positive power wires broke free from the connection in the tank. Not sure how but it was immediately obvious. The fuel pressure dropped quite a bit but car still ran. It was the primary pump that went out.

I am not sure of this but I think the fuel from the secondary pump back filled into the primary line to keep me running.

I went to two pumps because I was running out of duty cycle with 550/1600 and when I switched to 850/1600 the pump was losing pressure.

Good luck.

kuroi FD

Yeah you dont really need two fuel pumps unless your shooting for over 400.

RotaryResurrection

iTrader: (8)

I'm running a stocker plus a walbro which is turned on by a boost actuated (adjustable) switch. Each pump has a one way valve inside which prevents fuel pressure loss so all you need to do is tee them together. IF you chose to run them both at teh same time, all the time, you'd just tee the wires together as well. I chose to run mine seperately, because you dont need the higher volume when driving normally. I decided that I'd run the stocker right off the stock wiring/resistor as an attempt at better mileage and driveability, and turn on the second one only when needed.

The car is still waiting on a few parts and isn't 100% tuned but it seems to work fine this way, and even if one were to fail the other would still get you home because of the aforementioned check valves in the pumps. Besides, I cannot see how either of the pumps by themselves is quite as good as both of them running together. It's a cheap way to maintain pressure and volume on the top end.

neit_jnf

iTrader: (17)

thanks for the replies!
now another few questions, will using two pumps tee'd together increase pressure or volume or both, and by how much? will the fuel system get over-stressed maybe start leaking or other damages?

RotaryResurrection

iTrader: (8)

You shouldnt spring any leaks, no. A fuel system should be set up to hold pressure up to at least 80-100psi generally. Running dual pumps should increase volume on the top end and will maintain pressure where it might otherwise drop off when those big secondaries open (volume and pressure are closely related in this regard). With a properly functioning fuel pressure regulator it shouldn't really increase pressure by more than a few psi, if any.

maxcooper

Run the Walbro only. You don't need two pumps, so keep it simple.

It would only add volume, which is fine because that's what you need. However, pressure drops when you run out of volume, so having enough volume will keep pressure at the regulated level. In that sense you might think of it as "adding pressure", even though I wouldn't say it that way.

-Max

neit_jnf

iTrader: (17)

thanks everybody! I decided to run just the walbro to "kiss" but I'll save the stocker in case I need it in the future... should I oil it or something to prevent it from going bad?