I'm building a forged 383 with T-trim blower looking to run around 15#. Hoping to see 600+RWHP. Currently I'm running 42# Lucas injectors in the setup in my sig. Will these injectors handle that much HP or am I asking too much. Thanks for your help, Rob.

 

Sounds like you're asking for too much out of them. The concensus on the board seems to be from low 500's to mid 500's depending on fuel system, regulator settings, etc... Just out of curiousity how much were you putting down before with you're old s-trim and how much boost were you running. Also was that with stock heads? Thanks

Mikey

 

I was putting around 400 down at the wheels when I had it dyno'd. It was running extremely rich that day, pegging the wideband. I haven't been back to the dyno since I tuned it up. It still runs a little rich though. Heads are stock castings that have been ported and polished with a matching intake. I know I'm going to have to get better heads as well, just not sure on which ones to get.

 

Just playing with numbers, 600rwHP with the 4L60E and a loose converter is going to mean about 730flywheelHP. Assuming a BSFC of 0.55 #/HR/HP:

730 x 0.55 = 401.5 #/HR

401.5 / 8 = 50.2 #/HR per injector.

Assuming you want to follow conservative guidelines and hold the duty cycle to 80%, you need an injector that will flow 62.7 #/HR.

You need either a 64# injector running at 43.5psi, or bump the fuel pressure to 60psi and you could get away with a 54# injector is there is one that size.

This really needs to be on the Forced Induction forum.

 

are you running a stock bottom end? just wondering...

hey injuneer....what fuel pressure would i want to see with 42# injectors....6psi boost and around 415-420rwhp?

 

Do they make injectors that big that I can run with the factory PCM, or do I have to run an impedance box from acceleronics? Thanks, Rob.

 

58# -60# is the highest I've seen so far for a high impedence injector. I guess it's going to depend on how much horsepower you're planning on. If you plan on going any high I'd start saving for the low impedence + box to run them.

 

stock bottom end? thinking no...

 

Stock bottom end for current setup, forged for new setup. 4 bolt splayed block, Callies 3.75" crank, Callies 6" rods, JE pistons, hellfire rings.

 

So would these injectors work from racetronix (60lb/hr / 630cc) Shorty High-Z*? They are made by Siemens. Thanks, Rob.

 

I've seen 42# injectors do 600rwhp but with 60psi base fuel pressure

 

im running out of injector with my 42's at about 400rwhp (cant get any richer than 13:1) on stock FP (well 53psi at full boost anyways)

to answer ramer, yes, High Z means high impedence, Z is short for ohm.

 

Thanks for the help guys. Look like I'm gonna get the 60# High impedance injectors.

 

Z is short for impedance there is a difference. I ran my 42's up to 542 rwhp, but that was at a really high 96% duty cycle. No clue how you can be injector limited at 400 hp with 42's, you must have something else wrong.

 

I'm not injector limited with my "current" setup. Building a 383 with T-trim running 15-18#. I have plenty of injector right now, I need more for the "new" setup.