Forgot to add: here is a cool little tool -
Injector Calculator

I hate seeing people buy parts they don't need! Just some helpful information.
Try that calc., put in 8 cylinder, just some averages like .50 BSFC, .75 DC, choose 600cc injector (57lb), see how much power they support (685rwhp at only 75% duty cycle)? Now try with .90 DC (822 rwhp) - kinda cool huh? He has enough injector.

Although the Bu-hogs always need more injector for our little 6 cylinders...heh heh.

 

The 57# Siemens are more like 690cc injectors at our fuel pressure. They are rated at 43.5psi but, our fuel pressure is 58-59psi and is manifold pressure referenced.

 

hey guys, i appreciate your opinions and past knowledge but i have a few things for ya.

first, my truck is 4800lb's, about 4700lb's race set up.

how is duty cycle not important? it is directly calculated off of rpm and IPW, on my previous set up i was seeing over 100% duty cycle and right when it hit 100% the wideband would begin to go lean. might as well let efilive calculate it for me.

i have no idea when the pumps will be maxed seeing that i have stock fuel lines still but i bet it is pretty close to the same time as the injectors hit 100% and the turbo gets over 90lb's of air, everything seems pretty well matched to max out at the same time.

nosjohn, the injector calculator you are using is for fwhp not rwhp. lets go ***** out, usually see .55or above for BSFC for turbos, 100% duty cycle, and 66lb(57lb but at 59psi) injector, that is 960fwhp. no idea on the drive line loss but i run this turd in 4wd and have a 4l80e tranny, going to guess 25%, that puts me at 720rwhp.

not really suppose to goto 100% duty cycle so that tells me i will run out of injector before i run out of turbo, if i goto 100% they are well matched. i know alot of people that go to 100% even with boosted setups and aren't having problems, i will probably try it too.

i have done a little research on this stuff, im not just tosing parts at it and cranking the ****.

 

Yep, I agree Parish, I knew that calc. was for that, hence the Nissan site but it's just as well. I thought it would be cool for some of these guys to mess around with versus real calculations...hahhaa, j/k. I mentioned, on average, the trucks weigh that much. I realize you're not just throwing parts...like I said you're truck is running great. This is a great discussion because fuel injection can bring up so many variables, similar to octane ratings, oil quality (petro vs. syn.) and what is more detrimental to a motor - boost or nitrous?

Here is one of our recent ones on injector DC:
http://www.turbobuicks.com/forums/sh...threadid=20689
VERY interesting reading!

Did you say or not whether you are using a WB02 or EGT? I think you're on the right track, I still want to know what A/R your turbine housing is...lol.

 

t76 q trim, .96ar, and i am using a wideband but no egt gauge.

 

104 gas?

What timing are you running?

 

no, 111leaded, 18-19deg of timing, i have the heads off now and am going to post up some pic's, see what everyone thinks as to weather it was detonation or lifting heads.

 

give it hell Parish....you'll get 10s soon enough. you need to buy a set of heads for it while they're off. just get whatever heads you'll user on the 409 and put'em on the 6.0 for the time being. that should be enough power to get you into the 10s with a little more time.

 

Got any pics of the plugs too? The problem with inaudible detonation is that it work hardens the parts making them more suceptible to cracking.

 

Take some pics of the gaskets and block where the head/gasket resides.