Fuel pump upgrade?

[ls6monte]

I have an 85 Monte with an Ls6 Vette engine and i'm running a stock GN pump. I have an adjustable fuel pressure regulator that is adjusted from 47 psi for a stock GN pump to 62psi that the ls engine needs. The pump has been in the car for about 4 years now, but i'm having some problems running lean on the top end. I believ the stock pump is running out of pressure/volume on the top end. I want to upgrade it but I don't need anything radical. I have heard of using the 89 Turbo Trans Am's fuel pump but am not sure about that. I want to keep the stock in tank pump also. Any ideas of what I can do? Thanks
Ron

 

[Thumper]

Check with racetronix, a vendor on here, they can hook u up.

Thanks
Bill

 

[87GN_70GS]

If you can turn down the fuel pressure and increase your injector duty cycle you will be able to squeeze a bit more out of the stock pump. That will require a re-tune.

 

[ls6monte]

Thanks! The ls engines require a mininum fuel pressure of 62 psi so I can't really turn down the pressure. I understand about the retune as I have to get it back to my friends shop anyways so he can make sure it's the pump or something else.

 

[CaptainInsane-O]

Stock GN pump was barely adequate for the cars back when they were new... asking one to push 60+ psi to support that LS6 is really asking for trouble. Racetronix or Ful Throttle can hook you up with a Walbro that'll install right in the stock location & flow plenty of fuel to support that V8.

 

[ls6monte]

I actually had a Walbro(I forgot which model) when I first put the engine in, and it was way too much pressure for the engine at the time. This was before I had an adjustable regulator installed. Thanks again!

 

[White Out]

What about a Bosch 044?

Nick

 

[87GN_70GS]

What about a Bosch 044?

Nick

Also the Walbro GSL 392 external pump.

 

[ls6monte]

I'll have to check out the Bosch pump and I really don't want to do an external pump. The fuel lines have already been upgraded. Thanks again!

 

[White Out]

Bosch can be an in-tank. It is what a lot of the street 500+awhp WRX/STis are running.

Nick

 

[87GN_70GS]

The Bosch 040 is the in-tank version.

 

[White Out]

044 can be used in-tank,

What Fuel pumps are people using on their 525+whp - Page 8 - NASIOC
Page 8

Nick

 

[ls6monte]

Thanks! I will definetly look into the Bosch pump.

 

[ls6monte]

I looked into the Bosch pumps and I think they are way more than I need. I'm only making 350 rwhp. I need an upgrade but don't want overkill. Any other suggestions? Thanks

 

[Racetronix]

I actually had a Walbro(I forgot which model) when I first put the engine in, and it was way too much pressure for the engine at the time. This was before I had an adjustable regulator installed. Thanks again!

You have answered your own question. Put a Walbro GSS340M back in. LS1 factory fuel pressure is 58PSI not 62. You don't have a jet pump so you can run any pressure you want as long as your tune is setup for it.

 

[ls6monte]

Thanks! Going to do just that this upcoming week!
I was told an LS6 was 58-62psi.

 

[87GN_70GS]

044 can be used in-tank,

What Fuel pumps are people using on their 525+whp - Page 8 - NASIOC
Page 8

Nick

Nice. If that's the case then looks like the Bosch 413 can also be used in-tank, making it the highest flowing single pump in-tank.

 

[ls6monte]

I put the walbro back in last night with a new sending unit and everything went smooth. Plenty of pressure with no problems at all with the adjustable regulator. The old pump was losing pressure which I believe was at least part of my problem. Thanks again for all the help everybody.

 

[65malibuss]

Why does the LS6 require that much fuel pressure?
Fuel injector design?