LArger fuel system

[Lvnspeeed]

Is there someone who makes a larger sending unit for a stock gas tank? I want to run a -8 to the motor and a -6 return. I already have a walboro pump. I know its over kil for a 3.8 but its a good thing I running a 4.8 V8 with a 70mm turbo :biggrin:

 

[DailyDrifter]

The best you might get is a Double pumper, or pm turbofabricator, he can probably make one for you with -8an lines.

 

[turbofabricator]

There are lots of ways to accomplish your goals.

1) Modify your stock sending unit for double pumps.

2) Modify a stock unit with a 1/2", 5/8" or 3/4" pick up and run an external pump.

3) Use a fuel cell

4) Sump a new stock tank

5) Build a dual pump/dual outlet sending unit like this one: http://www.turbobuick.com/forums/general-turbo-buick-tech/215155-new-double-pumper-sending-unit.html

6) Use larger feed and return lines with a stock rail by building one of these to replace the stock regulator (on a V6, but not sure what would be needed with the 4.8) (WHY a 4.8 when the are the same physical size as a 6.2?.....no replacement for displacement.) Unless you already have a 4.8 and don't have the funds for a 6.0 or 6.2, that I understand.

 

[DailyDrifter]

There are lots of ways to accomplish your goals.

1) Modify your stock sending unit for double pumps.

2) Modify a stock unit with a 1/2", 5/8" or 3/4" pick up and run an external pump.

3) Use a fuel cell

4) Sump a new stock tank

5) Build a dual pump/dual outlet sending unit like this one: http://www.turbobuick.com/forums/general-turbo-buick-tech/215155-new-double-pumper-sending-unit.html

6) Use larger feed and return lines with a stock rail by building one of these to replace the stock regulator (on a V6, but not sure what would be needed with the 4.8) (WHY a 4.8 when the are the same physical size as a 6.2?.....no replacement for displacement.) Unless you already have a 4.8 and don't have the funds for a 6.0 or 6.2, that I understand.

Where did you get the top of the sending unit? Did you make or buy one? Also what did you use to isolate the positive and negative terminals for the pump?

 

[Fuelie600]

I want to run a -8 to the motor and a -6 return. I know its over kil for a 3.8 but its a good thing I running a 4.8 V8 with a 70mm turbo :biggrin:

This is over kill for a Walbro pump, but certainly not for a 3.8. Alot of the faster guys run more line than this. Good luck with your project---I believe Turbo Fabricator can help you out.

 

[turbofabricator]

Where did you get the top of the sending unit? Did you make or buy one? Also what did you use to isolate the positive and negative terminals for the pump?

I made everything. I used 3/8" nylon bolts and gun drilled them (drilled through the centers) and tapped them 1/2 way through for 10-32 cap screws. I only tapped them 1/2 way so the bolts would seal when they cut through the rest of the way, like a nylock nut. I also used O-rings on both sides of the nut and bolt. I have now found a source for the electrical connector for the top, and would recommend this, instead. Products Page They can build you anything you may need, too. (but I have never dealt with them, yet, so you're on your own if they do good work) I still have the prototype sending unit available. I am selling my car, and never installed it.

Personally I feel that an external pump with either a sump or a large pick-up installed in the stock hanger is the better way to go. Or a Denso 280 in tank. Opinions vary greatly on this, though. More than one way to accomplish your goals. A Double pumper form Cottons or Red Armstrong works well, too. (so I hear, anyway)

 

[Lvnspeeed]

Turbo just so I have this correct leave the stock line, pickup,ect and just run a double pumper?

 

[turbofabricator]

If you are planning on running faster than 10.2 or so, replace the entire fuel system. Grumpy runs in the 9's on stock fuel lines, WITH alky. I would suggest replacing all the fuel lines with AN or metal lines. Even -6AN is a HUGE increase over the stock feed line. The stock feed line necks down to .257" at EVERY saginaw fitting (i.e. fuel filter, frame to engine, and fuel rail) So basically, the stock fuel system is a 1/4" line. Big enough to make 600 hp. but I think you are on the edge at that point, and every ar is different, in that there might be kinks in your lines, and it will not flow as much as other cars.

 

[mojilla]

Does anyone have a picture of the modified pick up? Where would the fuel pump be mounted?