Questions about running two fuel pumps...

[Stratous]

To build the engine like I want, according to Mike at FM I need to run two 255lph fuel pumps, one in tank, one in line. I am planning on making my own fuel lines, with 3/8" braided stainless lines.

Is the second pump supposed to suck from the tank on it's own, or is it supposed to be inline, just like the filter?
Can the second pump by powered by the primary pumps wiring, or does it require it's own power source?
Is 3/8" lines too big? Whats the factory lines, 1/8"? I know it's a lot bigger but it's got to keep up with either 55 or 72 lb/hr injectors depending on what I choose.

Unfortuneatly my brother's friends that I always go to for help run big Mopar V8s and can get pumps larger than 255lph. Hell, one of them is running 3/4" fuel lines on his 800 horse 499 stroker.

[anonymous_user]

Dual pumps are a bad idea.

If you are needing more fuel than a single pump can supply, and for some reason, the second pump fails, you will lean out the engine.

Like you said, there are plenty of pumps out there that flow more than 255 lph, they just won't drop right into the tank.

[Dusty_Duster]

Quote:

Originally Posted by anonymous_user Dual pumps are a bad idea. If you are needing more fuel than a single pump can supply, and for some reason, the second pump fails, you will lean out the engine. Like you said, there are plenty of pumps out there that flow more than 255 lph, they just won't drop right into the tank.

+1

Summit Racing sells lots of fuel pumps. Check there.

[Stratous]

Okay.

All the universal pumps are 'in-line'. How can I replace the intank with an inline and still get accurate fuel level readings?


EDIT - The Edelbrock direct replacement pump, will do 255lph at over 90psi!
How well do you think this pump would hold 30 psi?
For the most part this car will only be around 20#s, but for the normal burnouts in front of the neighbors house and track runs she'll be up over 30.

[anonymous_user]

Remember that fuel pressure will be around 55 + maximum boost, so your saying 30 psi boost that comes to 85 psi fuel. Right at the rated limit of the Edel pump.

Ditch the factory fuel tank. Install a fuel cell, proper fuel pump, proper fuel lines, and an aftermarket fuel level gauge.

Yeah, that is extreme, I'm sure you can figure out a way to use the factory tank and modify the pump hanger to accomodate a pick up tube.

[Stratous]

Quote:

Originally Posted by anonymous_user Remember that fuel pressure will be around 55 + maximum boost, so your saying 30 psi boost that comes to 85 psi fuel. Right at the rated limit of the Edel pump. Ditch the factory fuel tank. Install a fuel cell, proper fuel pump, proper fuel lines, and an aftermarket fuel level gauge. Yeah, that is extreme, I'm sure you can figure out a way to use the factory tank and modify the pump hanger to accomodate a pick up tube.

The car is primarily being built for show. Full media blast, roll bar, and flawless paint job, along with mostly new interior. BUT the engine will put down ATLEAST 400WHP.
A fuel cell IS an option, but must be able to mount in the factory location and the pump MUST be able to register the stock fuel guage.
Other wise I was just gonna get a new replacement fuel tank with two pumps.

I still have to call Todd, the local 2.2 engine guy. I'll ask him as well. Personaly, with a good A/F guage, fuel pressure guage, and an ingition shut-off switch I think I would be good either way I go, but I always appreciate professional help

[puppet]

What are the other fellas running 400+HP around here using for pumps?
I can see upgrading the fuel lines but not sure if (2) pumps are a "must have".

[tkelly27]

Single walbro 255 will flow enough for 500hp. The in tank fits right in. Dual pumps will either outflow your stock regulator by a ton, or push double (double!) the pressure output depending on weather they are parralel or in series.

Fuel level readings are never really accurate, and the itty bitty bit that the fuel pump no longer displaces won't be a huge deal if you do decide to go to an external unit. What is a big deal is modifying the sock to fit on the end of the hose so that it's not sucking up sludge from the bottom of the tank, and keeping that hose in a good relatively low position on the tank. Yuck.

[Stratous]

Quote:

Originally Posted by tkelly27 Single walbro 255 will flow enough for 500hp. The in tank fits right in. Dual pumps will either outflow your stock regulator by a ton, or push double (double!) the pressure output depending on weather they are parralel or in series. Fuel level readings are never really accurate, and the itty bitty bit that the fuel pump no longer displaces won't be a huge deal if you do decide to go to an external unit. What is a big deal is modifying the sock to fit on the end of the hose so that it's not sucking up sludge from the bottom of the tank, and keeping that hose in a good relatively low position on the tank. Yuck.

Thanks for the info...
And it will be a brand new tank.