Fuel line configuration at fuel rails

[Rob_85Ttype]

Why are many turbo LS folks splitting the fuel supply line prior to the rails and thus supplying the fuel rails in parallel, rather than using the old turbo 3.8 factory method of supplying one fuel rail side and then the other fuel rail in series?

Ive seen many examples that have an 8 supply that they split to double 8s, supplying each rail, then joining back together at the regulator, and returning to tank with a 6.

I don't see a benefit of that over supplying one rail with an 8, the routing to the other rail with an 8, then onto the regulator, and back to the tank with a 6.

 

[Boost231]

That's how I have mine for the most part.

-10 leaving the tank
y fitting right before rails
-8s feeding the rails
-8s out of the rails to the regulator
-8 return
Y split of flex sensor.

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[Rob_85Ttype]

LS or hot air 231?

 

[Boost231]

ta alum block and heads.

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[NY Twin Turbo]

That's how I have mine for the most part.

-10 leaving the tank
y fitting right before rails
-8s feeding the rails
-8s out of the rails to the regulator
-8 return
Y split of flex sensor.

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Same here. Except I have the regulator on the rail. But essentially its the same thing.
I feed the rails from a "Y" at the back of the intake. Then in the front of the drivers side rail is the regulator. The passengers side rail has a cross over under the throttle body to another port on the regulator. Then the return leaves the regulator from the bottom to go back to the tank.

"They" say that if you run monster injectors in a single strait line, you may dump a lot of fuel from the first injectors on the line, thus depriving the last injectors of full fuel pressure. Also something about the pulses of pressure from opening and closings may screw up the flow.

I'm not sure I believe this. I can't test it. And I certainly can't do the math to prove it.

But sometimes its easier to just follow the standard rule. It wasn't difficult to do. A few more fittings, but whatever.

 

[markcerrillo]

That's how I have mine for the most part.

-10 leaving the tank
y fitting right before rails
-8s feeding the rails
-8s out of the rails to the regulator
-8 return
Y split of flex sensor.

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Im about to drop a LS2 in an 87 buick.. my concern is the original fuel rails.... would these work? What adapters, are needed, ? Ect.. thank you. Ps.. I'm going with a performance fuel rail.

 

[Boost231]

The above is done to my v6 motor. Can't help you on stock lsx stuff.

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[Rob_85Ttype]

http://ls1tech.com/forums/fueling-i...-lonnies-double-pumper-8feed-6return-kit.html

In series will support 1000 HP per Lonnie's Performance. I plan to give it a try. -08 in to pass fuel rail, -08 over to driver fuel rail, regulator, -06 out.

 

[Chuck Leeper]

My LS combo has:
3/4" o'ring fittings w/ -8 AN at the ft ends of the rails. They are tied together w. a -8 AN tee on the dr ft rail, and then into the -8 feed line from the pump{s}.
The rear ports of the rails are tied the same way, using -6, out to the reg, with -6 to the tank.
I use Fragola line and fittings. Racetronix dual 340's in the tank.
The turbo is good for about 95#, so this combo, along w/ 80# dekas run at 4 bars, has me covered on fuel.{Pump gas}.
Alky Control is also on the car.

 

[chub406]

I have the Holley 1800 fuel pump. A -10 to -8 Y. then 2 fuel lines up to the rails. From the rails tot he reg. Then -10 back to the tank.
Yes. both ways will work. Like NY said. Some guys say this is part of the issue with why #7 goes lean as well. Why alot of guys will fatten that cylinder. I have no tests either to back either.
I knew I wanted to have the reg after the rails. That I'm a huge believer in. If you are running a reg before the rails and esp feeding one line. That I could see not having the same pressure once it gets through the first cylinder to the last. Now enough to make a big dif? Thats debatable.
reason I did it.
1. im running e85 and an s480 etr ho. I want to know my fuel system can keep up.
2. There is no such thing as over kill on a fuel system.
3. regulator after the rails. duel in, 1 out with boost reference.
4. It helps me sleep at night knowing I will wont have to tear it out and prick my fingers and thumb, putting braided line fittings on because I didnt go big enough the first time.
5.It looks dam sexy. ;]

 

[Chuck Leeper]

Some guys say this is part of the issue with why #7 goes lean as well. Why alot of guys will fatten that cylinder. I have no tests either to back either.

Some also report that blocking the rear steam ports add to this issue...Don't know. All 4 on my engine are hooked up.
The 1800 pump now E85 compatible? A couple yrs ago, Holley suggested not.

 

[chub406]

This is what I put on another thread about the steam ports.
The reason they have them is because on a 23* head old school smallblock. the highest point of the cooling system with the thermostat closed was the thermostat housing outlet. Air pockets travel up. The thermostat opens and the air pocket goes to the radiator. Thats why alot of guys will drill a tiny hole in the thermostat. To let the air escape.

On an ls. The heads are the highest point and the thermostat is on the inlet. The air pockets will go to the heads. The water pump circulates the coolent, then the thermostat opens and let the cool coolent in. If they are blocked off. Now you are trying to get those air pockets out, in the very corners of the heads, on a theoretical "dead head system". If you cant get that air pocket to move I could see it causing a hot spot in the head. If you can get it to move. You have to hope it gets it all the way cycled through before the thermost closes and gets into the radiator. This is why the line goes to the radiator. Soon as the thermostat opens. you got a direct shot to the radiator.

Some guys say its contributes to the back to cylinders getting hotter. Esp with the #7 cylinder. Other guys will argue till they are blue in the face and say cap them off.

Both ways will work. Im not saying anyone is better than the other. Im just summing up what I learned when doing this. lol

I believe its worth every penny to vent them out. Its something thats cheap and no way can it hurt in anyway. It can only help. Plus with mine being a transplant. My geometry might not be right and the front or rear higher than the other. I did all 4. If nothing else. It makes me sleep better at night. lol

It better be e85 compatible with as much as I spent! lol I got it about 2 years ago now. I called them and got all the part numbers and e85 filters. They said it would be fine.