i just maxed out my 41lb(at 59psi) injectors and i just maxed out my fuel pump. my truck came with 19lb injectors that i upgraded to to the 41's, i had no problem at all geting these to run well. i need to upgrade again, from what i understand 50lb's is as high as i can go. will there be any issues with the 50lb units or will they be just as easy as the 41's were? who has the best price on 50's?

i also need a fuel pump, i would like to see it quite a bit bigger than whatever is in there, right now i am loosing presure at the shift points and i am sure i will want to get more power some day, maybe a small wet nx kit. anyone here know anything about fuel systems in the trucks? should i go intank, or inline or what?

<small>[ November 17, 2002, 02:30 PM: Message edited by: parish8 ]</small>

 

well first off how much power you want to push from that truck. Secound when I put bigger injectors in it seemed like it helped but after I put in a inline fuel pump I have tons of fuel to spare. So before u upgrade injectors do a inline fuel pump.

 

well right now i would like to be able to push another 2psi or so with the blower, maybe someday heads and cam, the formula i have shows 41's being good to 546hp and the 50s good for 666hp, i dont think i will make more than 100hp more than i am now. i might hit it with a wet kit if i ever beefed up the bottom end but that wont need bigger injectors. i am over 100% duty cycle now with the 41's, i might be a little rich but not much, going to get it on a dyno with a wide band this week so i might be able to pull some of that fuel out. definately need a pump though.

 

hey parish...check your pm

 

You should have no problems w/ the 50's. They are however, the largest you can go w/ high-Z injectors. After that you'll need an injector driver box, or go to a low impedance capable EFI system.

Do you have an upgraded intank now??

I had great success w/ the 42's i had last year. And since going to the 96's i've had equal success. Even w/ the bigger cam, low CR, and fire hose injectors the A/F is right on and idle is steady. I did however have the injectors individualy flowed to get an accurate flow number for each.

The fuel system on the trucks is very similar to the cars, better for boost actually. The regulator is already on the fuel rail and referenced to the manifold. A decent intank will do well for you. Might even consider a dual intank if you plan to hit it w/ a decent sized wet shot.

 

this is all good. i have the stock pump and the presure falls from 62 to about 50 at the shifts and i am shifting at 5800, at that exact time my duty cycle is about 110%, i wouldn't mind trying the shift higher but i cant with my fuel situation.

prety sure the 50's will hold me but i really want to go all out on the fuel pumps just in case i want to hit it with i fat shot someday. is there any chance the duel pumps will overcome the return line? i doubt anyone knows if the duel set up that i have heard of will work in my truck, may need some modifying.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by y2khawk:
<strong>You should have no problems w/ the 50's. They are however, the largest you can go w/ high-Z injectors. After that you'll need an injector driver box, or go to a low impedance capable EFI system.

Do you have an upgraded intank now??

I had great success w/ the 42's i had last year. And since going to the 96's i've had equal success. Even w/ the bigger cam, low CR, and fire hose injectors the A/F is right on and idle is steady. I did however have the injectors individualy flowed to get an accurate flow number for each.

The fuel system on the trucks is very similar to the cars, better for boost actually. The regulator is already on the fuel rail and referenced to the manifold. A decent intank will do well for you. Might even consider a dual intank if you plan to hit it w/ a decent sized wet shot.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Harlan, let me get your opinion:

I have a 422 now with the D-1SC and 42# Injectors.
Before, with the 346, and 4.10" pulley, I made 5 PSI at ~ 6K RPMs and stock exhaust. Moving to the 3.20" pulley, I made 12 PSI with the stock exhaust; 9.5 to 10 PSI after putting on headers.

After putting the 4.10" pulley back on for my initial tuning with the 422, I see about 3 PSI at 6000 RPMs.

Questions:

1. Do you think the 42# injectors will handle the 422 and the 3PSI boost level?

2. At what boost level do you think I may get by if I moved to 50# injectors?

3. Do I just need to plan on low impedance injectors and drivers if I want to run about 7 or 8 PSI everntually?

Thanks, man.

 

Before you spend money on the injectors at least add a walbro gs340 (high pressure 255 lph intake pump). Its about $100 and will support at least 500 rwhp (higher if hotwired) or go with one of the dual intake pumps. Stock pump is being way overtaxed.

Gary