The return line must be at least as big as the supply line, minimum. Otherwise the return hose becomes the restriction. And if you are using a high GPH for application pump, it should be one size larger.
I've heard this before, but many don't agree w/ this. One of the engineers at Aeromotive recommended the -10 feed and -8 return on my car and it works flawlessly.
Many factory EFI applications use a smaller return than feed also.
I don't disagree that someone would tell you that. The tech guy I talked to at a company that builds high end carb fuel systems we've used told me same or larger. Along with the rest of it. You'll get different stories from different places, even though they are the ones who design, test and make the stuff.
My thoughts were, if you run it up through 16' of -10 and return it through 16' of -8, how can the smaller line not be a restriction, to some degree, with a big pump? I want to control fuel pressure at the carb with the regulator, I want it to be consistent regardless fuel demand of the engine and we aren't running a lot of fuel pressure to the carb.
Not all return regulators and systems are designed the same way. Different parts and pieces from different manufactures will function differently.
We monitor fuel pressure at the pump outlet and the return side of the regulator. There's always more than one way to do something. I'm happy with what we have.
