Has anybody converted their fuel rails to be returnless?
02-12-2007, 11:37 AM
#1
Has anybody converted their fuel rails to be returnless? My next item on the list of things to take care of is modifying the fuel rails/system. I've been reading up on how the LS1's have their fuel systems configured and wondered if this could be duplicated on an LT1? I already have an Aeromotive external FPR and was originally planning on mounting it to the firewall but if I can get away with mounting it close to the fuel tank and just have a single fuel line running from it to the engine bay, I'd rather set it up that way.
Can this be done? Does it require any special parts?
Can this be done? Does it require any special parts?
02-12-2007, 06:42 PM
#2
Originally Posted by thesoundandthefury
My next item on the list of things to take care of is modifying the fuel rails/system. I've been reading up on how the LS1's have their fuel systems configured and wondered if this could be duplicated on an LT1? I already have an Aeromotive external FPR and was originally planning on mounting it to the firewall but if I can get away with mounting it close to the fuel tank and just have a single fuel line running from it to the engine bay, I'd rather set it up that way.
Can this be done? Does it require any special parts?
Can this be done? Does it require any special parts?
Also, mounting any part of the fuel system on the firewall is against NHRA/IHRA general rules in regards to fuel systems.
02-12-2007, 10:18 PM
#4
Here's how a returnless system is set up:
Don't be fooled by the terminology: the fuel actually does get returned to the tank, it just does so in a different place. In the case of the LS1's, it's further back closer to the gas tank, rather than directly from the fuel rails themselves.
What makes you think that?
1. If fuel is returned from a FPR right outside the tank instead of after it's flowed through rails on top of a hot engine, it stays cooler. The cooler fuel stays, the slower it evaporates.
2. K.I.S.S method. One single fuel line running to the engine. If fuel demands ever become big enough that you need to run a dual feed setup, the return provisions are already in place. All you need to do is "Y" into the main feed line, and plug the second line into the other fuel rail. Much easier and clutter free than having two separate feed lines and two additional return lines plumbed directly off the rails for a total of four fuel lines.
This isn't some miracle horsepower mod, just a means of making things more streamlined.
Don't be fooled by the terminology: the fuel actually does get returned to the tank, it just does so in a different place. In the case of the LS1's, it's further back closer to the gas tank, rather than directly from the fuel rails themselves.
Originally Posted by GIZMO
If you make your system returnless you will probably have a bunch of hot start problems due to heat soak.
Originally Posted by LT1Falcon
im not saying there isnt an advantage, but what is the advantage in doing that?
2. K.I.S.S method. One single fuel line running to the engine. If fuel demands ever become big enough that you need to run a dual feed setup, the return provisions are already in place. All you need to do is "Y" into the main feed line, and plug the second line into the other fuel rail. Much easier and clutter free than having two separate feed lines and two additional return lines plumbed directly off the rails for a total of four fuel lines.
This isn't some miracle horsepower mod, just a means of making things more streamlined.
02-13-2007, 01:18 AM
#5
Yes it can be done. I would not do it 
I prefer to have better control and less pressure drop by putting the Reg on the return close to the fuel rail...like an LT1. Advantages are more stable fuel control and cooler fuel.
we have at least a Half dozen cars over 600HP running this way.
The biggest thing I see is people want what they do not have.Mustang guys want single lines and LS1 guys want duel
I prefer to have better control and less pressure drop by putting the Reg on the return close to the fuel rail...like an LT1. Advantages are more stable fuel control and cooler fuel.
we have at least a Half dozen cars over 600HP running this way.
The biggest thing I see is people want what they do not have.Mustang guys want single lines and LS1 guys want duel
02-13-2007, 11:28 PM
#6
One of the biggest issues with the LT1 is heat soak in the intake. Being that the fuel rails are also aluminum they also suffer the same issues. If fuel is not passing thru them they will not stay cool and you will have a hard time getting the car to crank. On the first LT1 I built I installed the regulator ahead of the fuel rails and I had a really hard time cranking it on hot days.
Daren
Daren
