I was hanging out with a 2007 S2000 owner and we were looking over the return line-less fuel system. Anyone know if there a specific name for this type of fuel system and where I can find a How-it-works type write up on it? Is there any greater performance potential out of a fuel system like this VS the conventional Fuel Injection?
Fuel system with no return line?
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The 1UZFE EGR Delete Kit is available for sale here.
fuel systems without a return line is simply called a 'returnless fuel system."
it's mechanics of it are pretty simple. instead of having a regulator on the motor, the regulator is in the gas tank. you can make some good power on returnless setups. i've seen mustang cobras make over 600, no sweat. but if you want total control over how mush pressure the injectors see, then you'll want to convert to a return style system.
but when it comes down to it... both return and returnless work the same way. except one system has the regulator on the motor and the other in the tank. one has a a return line the length of the car while the other has a very short "return" line. but both systems make sure your injectors see 3 bar, 4 bar or 5 bar of pressure (depending on auto manufacturer).
here's a link to read up on it...
http://www.aa1car.com/library/returnless_efi.htm
it's mechanics of it are pretty simple. instead of having a regulator on the motor, the regulator is in the gas tank. you can make some good power on returnless setups. i've seen mustang cobras make over 600, no sweat. but if you want total control over how mush pressure the injectors see, then you'll want to convert to a return style system.
but when it comes down to it... both return and returnless work the same way. except one system has the regulator on the motor and the other in the tank. one has a a return line the length of the car while the other has a very short "return" line. but both systems make sure your injectors see 3 bar, 4 bar or 5 bar of pressure (depending on auto manufacturer).
here's a link to read up on it...
http://www.aa1car.com/library/returnless_efi.htm
JustenGT8
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They are **** for FI as the MAP line is obviously long, causing delay in fuel pressure response....not critical for NA but can be pretty signifcant for a responsive FI setup.
gloverman
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Justin the returnless systems I have worked with dont have any vaccuum lines to the pressure regulator. They use atmospheric pressure and have run higher than normal static pressure. One really good thing is pressure at the injector is constant and I find this makes tuning very easy. Returnless systems could be a problem with very high boost. Cheers
JustenGT8
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Well aware of that mate, that's my point....to run FI you need a MAP ref and the line will be long. To run without a ref line and just a higher static pressure is far from optimum and belongs in the same bin as rising rate regs in my book.
gloverman
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One of my staff is doing a Turbo 3S Altezza at the moment and we have been discussing fuel pumps and fuel systems. Altezza ( IS200 ) run a returnless system standard. Some people just stick a walbro in the tank but we are reluctant with the upgraded injectors and still deciding on boost levels. It's hard to measure the flow on the system. pressure no worries but flow at that pressure is a problem.
Justin I am always reluctant to bring up rising rate fuel regs as people don't normally like my opinion when they just got convinced by a salesman to buy one on the understanding it will increase the fuel delivery enough to solve all a turbo vehicles problems.
We are seeing more and more returnless systems. Many recommend never changing the fuel filter which is often in the tank with the fuel pump. We have seen o-rings in the tank leaking fuel causing poor starting and lack of power. They work well on standard cars but with big mods things can get interesting. Cheers
Justin I am always reluctant to bring up rising rate fuel regs as people don't normally like my opinion when they just got convinced by a salesman to buy one on the understanding it will increase the fuel delivery enough to solve all a turbo vehicles problems.
We are seeing more and more returnless systems. Many recommend never changing the fuel filter which is often in the tank with the fuel pump. We have seen o-rings in the tank leaking fuel causing poor starting and lack of power. They work well on standard cars but with big mods things can get interesting. Cheers
defenatly not a problem in NA, Kawasaki ZX12r from 2004 and on have returnless syetems stock and do 190hp from 1200cc's
boost? I don't know.
why would you convert anyway? there's not a single piece of hp to gain in that manner. just easier to build in a factory + saves a return system and it's weight, which seems quite importand to the Bike boys for some reason, ghe hehe:wink1:
Grtz Thomas
boost? I don't know.
why would you convert anyway? there's not a single piece of hp to gain in that manner. just easier to build in a factory + saves a return system and it's weight, which seems quite importand to the Bike boys for some reason, ghe hehe:wink1:
Grtz Thomas
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