OEM Stock Pump Good For How Much NA ?

[thedak]

I was told 500 rwhp for a NA car.

Is this true ?

[mistermike]

The first trick is to get 500 RWHP NA in a car that's driveable.

There are no hard and fast numbers. In my experience, the earlier your torque comes on, the harder it is on the stock fuel system. The ability to deliver fuel with the stock setup has a time qualifier, that is, you have a certain amount of time before a turd floats to the surface of the punch bowl, due to the inablility of the stock bucket to refill itself fast enough. My twin screw setup, due to the extreme torque at 2500 RPM had the fuel system pretty much crying "Uncle" by 5000 RPM. This would not be the case with most N/A setups, as the torque curve isn't as flat. Nonetheless, to assign a specific number is disingenuous, as there are so many variables as to make that a dangerous proposition.

In the realm of opinion, I would say that if you are doing anything approaching 500 at the tires, cheaping out on the fuel system is false economy.

[thedak]

I should be close to 490 rwhp NA after the head install.

I guess I will order up a 255 to be safe.

Thanks

[Seth@HSC]

We ran out of fuel pump at 500 rwhp on a turbo motor. But forced induction requires more fuel than a NA motor at the same power level. For the cost of a fuel pump, I would just go ahead and replace it.

[Nomorefbodys]

450 na with stock injs no signs of any drop off at all from the stock system. I am getting close on inj though.

[Kingsize]

Dak... Although I am making over 500rwhp N/A now I have zero issues with fuel supply on a bone stock fuel system. I will say that for the cost of the 255 pump, it is cheap insurance. I am also in the planning stages of a fuel system in the GTO. I honestly don't trust it, and my luck isn't that great. :)

[thedak]

Thx guys

I am just going to order one from LPE to be safe.

[JS1965]

440RW on stock 06 system here....
Injectors are close...

[speeddemon]

whats $155 for a pump when you pay $1600 for heads and $800 for a intake manifold? :bomb:
this mod game isnt fair

[thedak]

I ordered a LPE GTO Pump Kit.

They said they are out of stock until next week.

FYI

[ericwilloughby]

450 na with stock injs no signs of any drop off at all from the stock system. I am getting close on inj though.

450 at the wheels? I dont see how you are doing it on the stock injectors.

[thedak]

450 at the wheels? I dont see how you are doing it on the stock injectors.

I did 442 RWHP on stock injectors.

@ 96% DC



Had a set of injectors (43lb @ 53psi) made up by Fuel Injector Connection.

Did 459 RWHP @ 77% DC.

[slammin86]

I ordered a LPE GTO Pump Kit.

They said they are out of stock until next week.

FYI


Yeah I ordered it last night and ended up with the same message today.

[thedak]

I wonder who will get thiers first ?

lol

[slammin86]

I wonder who will get thiers first ?

lol

Lol better be me.

Sucks though cause when I ordered it said it was in stock.

[JS1965]

Most people dont understand that a LS1 BSFC is better than most of the older engines of yesteryear...

Its Efficency is more on the lines of .040 Naturally aspirated....

So a 33lb injector will support 550 flywheel at 85% DC..I really dont know if my 06 pump is up to the task but so far I am around 80% duty cycle at 440RW and my AF is perfect...

I will go up to 42lbers real soon just to be safe..
If the stock 06 pump doesnt support the power at that point I'll add the LPE pump too

[thedak]

I am around 80% duty cycle at 440RW and my AF is perfect...


You must have some healthy OEM injectors to only be around 80%

[scot254]

Mistermike was silently promoting the 8.1L bucket mod. I upgraded the size to keep my pump from drying up the bucket and overheating. I'm pretty sure I ruined my first Walbro pump in the factory bucket from overheating. Otherwise drill a bunch of holes.

[slammin86]

Where do we drill the holes at?

[mistermike]

Most people dont understand that a LS1 BSFC is better than most of the older engines of yesteryear...

Its Efficency is more on the lines of .040 Naturally aspirated....


I found that out the hard way using the ubiquitous fuel calculators out there. I wanted a fuel system good for 1000 at the flywheel, and wanted to avoid going to lowZ injectors. The formulas told me for a blower to use a BSFC of .55-.60 and go buy an $800 fuel pump, which I did.

When I talked to several experienced LS1 tuners, I found out that I won't need that much fuel in the real world, especially with a twin screw. Those BSFC numbers must be from old flathead Fords.

If the 80lb Siemens injectors turn out to be any good, I can run that damn thing at 40 PSI and it will last forever.

[RSV]

We put 4 holes 3/8 holes near the bottom of the bucket. It seems to work well. I just try not to let the fuel level get too low.

[ericwilloughby]

Everyone on this board is big on drilling the bucket. I call BS. The inlet at the bottom is by far not the only way for fuel to get into it. There are a couple of big ass holes at the top.

http://www.ls1gto.com/forums/attachment.php?attach mentid=101048&d=1234893974

There is not only zero advantage to drilling the bucket, it can overheat and ruin the pump when the tank gets low because the venturi can't keep the bucket full with holes in the bottom. The venturi's purpose is to keep the bucket full even though the tank level may be nearly empty.

Keep the tank at least 1/4 full and these holes at the top will be submerged. If you are running the bucket drilled and less than 1/8th tank the LPE strainer sock can be exposed where it runs up the side of the bucket.

http://www.ls1gto.com/forums/attachment.php?attach mentid=103604&d=1238542307

The OEM sock is half this size and does not run up the side of the bucket.

http://www.ls1gto.com/forums/attachment.php?attach mentid=106225&stc=1&d=1241876855

[JS1965]

Mike I dont doubt you,U can throw all the BSFC out the window when u are talking about FI but for most NA setups like mine the 33's will get u to 450RW....

The fuel pump well that I'm not sure of,granted a DC of 80 is good but for short bursts at the track 90 is still fine....Again for a FI setup I totally agree,build it over kill or u could be looking at an new shortblock ;)