I am wondering what are the benefits of doing a return fuel system in our cars. I have seen a handful of people do this, soundperformance for one. Why is this beneficial? Is this a way to get more fuel using smaller injectors by installing a fuel pressure regulator?

 

yes you can get more flow out of your injectors with a return setup and fpr. it also increases the life of your fuel pump. you can also use smaller quieter pumps to make the same power.

 

So in an essence if you were to want like a lil over 350hp normally people step up to 700cc injectors. But with a return system you could actually get over 350 on 550cc injectors safely..? Without too high of a duty cycle

 

im not and expert, but my assumption is that when you uprage a fuel pump and have the ability to regulate the fuel pressure with a return system it will allow you to get a better spray pattern when going with large injectors. Especially at idle when a large injector opens it may not have enough pressure behind it to have a nice spray patteren which can cause a rough idle. Also a return system will keep the fuel cooler as it recirculates.

 

Ok. I guess Im going to read more into this.. Just gonna search around and see what I come up with..

 

I posted an answer to this questions a while back. Read it here:
https://www.scionlife.com/forums/vie...return#3183589

MrC

 

Do ya'll have that return-style billet fuel rail, regulator and fuel pump upgrade available yet..

 

i have to disagree with that. The fuel would be cooler if it didnt return since the fuel would pickup radiant heat from the engine and recycle it back to a tank of cool fuel. BUT the benefits of a return fuel setup outweigh those effects.

 

I am trying to figure out what you said... cause it is not making sense to me. What you just said was that heatsoaked fuel sitting in the fuel rail remains cooler than if it were to re-circulate through cool fuel in the fuel tank?? Think about how a radiator works

 

When reading Toyota's brochure about the benefits and new features of the 2az-fe it says that the returnless fuel system keeps fuel cooler and helps to reduce emmissions. No idea why but that is what it says.

 

reduces emissions cuz the injectors squirt a exact amount of fuel and no fuel is wasted/burned/whatnot it reduces hydrocarbons in hte exhaust.

 

interesting. make sure ya click the link up a few posts, definately the benifits are explained well.

although the dissapation of heat is a small thing, I see it like this:

the fuel rail gets heak soaked from the radiant heat of the engine, it must dissipate somewhere. Fuel is almost as conductive as water I imagine so it is dissipated to the fuel entering the rail... and with a returnless system 100% of that fuel gets injected. With a return system there is an actual flow occuringf through the rail although not high volume it still carries a certain amount of that heat soaked fuel in the rail back to the fuel tank where it dissipates heat. So in theory it would keep the fuel cooler in the rail. Now at WOT a large amount of that fuel isnt even returned odviously because it is flowing through the injectors.

 

watching.