Return style regulator with Mechanical Fuel Pump?

[jayb]

Its great to see data analysis tools in action!  Actual data from sensors and electronics is the racer's greatest ally...

[garyv]

If you are running an electric pump is it really necessary to run a return style regulator?
If so how do you plumb up the return line into the tank?
I was thinking of running an Aeromotive pump and regulator.
Thanks
garyv

[jayb]

The Aeromotive fuel pump regulators that I've used have all been return style, although they may make some dead head regulators too.

The return line can go anywhere in the tank, but I usually put them at the top of the tank.  If you don't want to pull the tank and put in a fitting, one work-around is to plumb a fitting into the rubber filler neck hose.  If you use an AN bulkhead fitting with a 90 degree end, and install it so that the 90 degree end is pointing down into the tank, you won't have to worry about the fuel splashing around in the hose and potentially coming out past the gas cap.

[drdano]

Here is a decent read on the topic along with some nice drawings of systems http://www.centuryperformance.com/forum/showthread.php/55-Fuelish-Tendencies

I never thought about a return line into the filler, that is a good idea.  I think the most preferred way to do it is have the return fitting submerged so you're not aerating the fuel, especially important with a high flow pump that is sending most of the fuel back.

[jayb]

I think the most preferred way to do it is have the return fitting submerged so you're not aerating the fuel, especially important with a high flow pump that is sending most of the fuel back.

Makes sense...

[cammerfe]

Plus one on Jay's comments. When we put EFI in Brother Lon's '67 Mustang we put the return in the filler neck. It's easy to take the elbow out of the back panel. The return went in the metal tube elbow where it had a straight shot back to the tank.

The last time I put in a return, it went into the top of the methanol fuel cell in the trunk of my ECTA car. With the filler cap assembly removed it was easy enough to put one hand inside to tighten the nut on the bulkhead fitting.

I was cautioned against going below the fuel level due to the problems induced when pumping against a 'head'.

KS

[drdano]

I was cautioned against going below the fuel level due to the problems induced when pumping against a 'head'.

Interesting.   I thought that having the return dump waterfall style back into the tank would induce a lot of foam in the tank.  Here is a good video showing such a situation, though they're returning a hell of a lot of fuel.

http://www.youtube.com/watch?v=dP6Pogm6Ts0