Fuel Delivery Question

[Underboost]

OK so a -8 from the pump Y'd off to two more smaller -8's into each Champion fuel rail and a -6 return would work just fine.

Weldon pump, Weldon controller, A Good Filter, Champion Fuel Rails, -8 feed & -6 Return?

 

[bison]

Louie Lopez and I talked about this issue a while back. It seems he still had issues even with the -an lines on a stock rail until he put a Weldon pump on. I still fill an intank pump and -an lines still can't move enough volume through the rail to support 9 second power.

Wont be a problem because i will have the GN1 intake and dual fed rails on there. Pump and lines will be the problem over about 22 psi.

 

[Dusty Bradford]

OK so a -8 from the pump Y'd off to two more smaller -8's into each Champion fuel rail and a -6 return would work just fine.

Weldon pump, Weldon controller, A Good Filter, Champion Fuel Rails, -8 feed & -6 Return?

-8 feed is fine. You can y it into -8 or -6 into the rails. -6 is still plenty, whichever you prefer. -6 for return

You'll need a 100 micron filter on the pump suction and a 10 micron on the discharge side of the pump.

 

[Underboost]

-8 feed is fine. You can y it into -8 or -6 into the rails. -6 is still plenty, whichever you prefer. -6 for return

You'll need a 100 micron filter on the pump suction and a 10 micron on the discharge side of the pump.

Cool Yeah I think -8 Y'd to two -6's makes more sense. Thanks again Dusty.

 

[nordy racer]

These aluminum fuel rails came off of my full race ported Champion GN1 intake as delivered to me.

I can't get a grasp on how the Champion fuel rails supply the engine with more fuel when they are actually slightly smaller internally than the stock fuel rail? In the pictures below I have drawn a line identical in length to the max bore size of the aluminum rail and put the same red line on top of the stock rail. I can't find a piece of scrap stock fuel rail to actually measure the internal diameter. I'm guessing the thickness of the wall is about .050" thick. Even if I take .100" away from the total outside diameter of the stock fuel rail it's still slightly larger than the aluminum rails internal passage.

Also, look at the small crossover with the 90* bends and the MUCH smaller openings in the fittings? How can that help flow to the drivers side cylinders unless people feed BOTH sides of the aluminum rail...which would cure the leaness of that bank of cylinders.

YEP... you don't need this set up on a 109 block.. the stock rails will handle it fine (i still run my stocker).. all you need are larger feed lines and return lines..

 

[bison]

YEP... you don't need this set up on a 109 block.. the stock rails will handle it fine (i still run my stocker).. all you need are larger feed lines and return lines..

Not in Dusty's case in post #4. It was the stock rail that caused the leanouts as evidenced by the DC % increasing at the end of the run even with the larger injectors. Like he said some can take it and some cant.

 

[Turbo1dr]

Like he said some can take it and some cant.

I'll bet the fuel pump(s) on that particular car didn't work as good as the ones on cars that don't have the problem. The main thing is it's cured.

 

[Dusty Bradford]

I'll bet the fuel pump(s) on that particular car didn't work as good as the ones on cars that don't have the problem. The main thing is it's cured.

In our case it was ATR double pumpers, then Red Armstrong double pumpers, then new hot wires for both pumps, then an alternator that put 15 volts to them, then -8 feed to the rail...etc. We tried everything and still hurt #1 more than once. This problem never existed until we crossed the 9.8 range. I'd say a large external like a Weldon to the stock rail would have fixed it with the -8 feed. It's fixed now for good.

 

[bison]

I'll bet the fuel pump(s) on that particular car didn't work as good as the ones on cars that don't have the problem. The main thing is it's cured.

Maybe but ive seen more problems with feed lines than with pumps over the years working on cars. They just get banged up or are bent slightly different causing various unseen restrictions. Ive seen compression fittings used to fix or connect new line on cars ive worked on . Those will always cause a problem trying to extract maximum flow from steel lines. The consensus seem to be if over 125mph at 3500 lbs go for a DP'r. If over 135mph go for the -8, -6 setup and run an external and aftermarket fuel rails. One bad leanout is going to cost a hell of a lot more than the pump and lines.

 

[Underboost]

Maybe but ive seen more problems with feed lines than with pumps over the years working on cars. They just get banged up or are bent slightly different causing various unseen restrictions. Ive seen compression fittings used to fix or connect new line on cars ive worked on . Those will always cause a problem trying to extract maximum flow from steel lines. The consensus seem to be if over 125mph at 3500 lbs go for a DP'r. If over 135mph go for the -8, -6 setup and run an external and aftermarket fuel rails. One bad leanout is going to cost a hell of a lot more than the pump and lines.

Bison, I have a compression fitting used to fix a leaky fuel line by the passenger side header. That would slow the flow? If so then this is contributing to my problem.

 

[3.8vsix]

Are most of you guys running a fuel cell with this setup or a stock tank sump.

 

[bison]

Bison, I have a compression fitting used to fix a leaky fuel line by the passenger side header. That would slow the flow? If so then this is contributing to my problem.

Compression fittings squeeze the hell out of the line and reduce the cross sectional area restricting flow tremendously. This is really bad if its a feed line and will limit the potential of the stock lines a lot. If its a return it will just act as a fuel pressure regulator itself making the regulator at the rail nearly useless if trying to go below the flow level of the restricted compressed line where the fitting is.

 

[Underboost]

Compression fittings squeeze the hell out of the line and reduce the cross sectional area restricting flow tremendously. This is really bad if its a feed line and will limit the potential of the stock lines a lot. If its a return it will just act as a fuel pressure regulator itself making the regulator at the rail nearly useless if trying to go below the flow level of the restricted compressed line where the fitting is.

It was the return but it doesn't matter now all fuel lines are ripped out, going with AN's I'm sending Bill Anderson my old intake 340 pump so he can modify it with -8feed & -6 return.

 

[bison]

It was the return but it doesn't matter now all fuel lines are ripped out, going with AN's I'm sending Bill Anderson my old intake 340 pump so he can modify it with -8feed & -6 return.

I picked up a sump for a stock tank that uses up to a -10 feed. It has 1/2 inch copper tubing soldered to the factory sending unit and you can run a nice regulated external pump. Thats what ill be installing before i turn it up with the race ported GN1's and the GN1 intake.

 

[Ed Valvo]

What brand and model fuel lines are you guys running?

 

[bison]

What brand and model fuel lines are you guys running?

We switched or are switching to -8 teflon braided line and splitting under hood to to a pair of -6's feeding champion rails on both sides.

 

[Ed Valvo]

Teflon to eliminate leaks? Got heavy fuel fumes here with non teflon line......

 

[bison]

Teflon to eliminate leaks? Got heavy fuel fumes here with non teflon line......

Teflon is more expensive but doesnt seep fuel and smell up the garage.

 

[Underboost]

Wow this is old! Here are some pics of what I did.

Before my 4'' intake

 

[TURBOELKY]

Wow this is old! Here are some pics of what I did.

Before my 4'' intake

hey Brent. What is that hanging over your driver side upper control arm? a vent for the fuel cell with a filter on it?