A.R. Shale Targa

iTrader: (2)

At what power level do these pieces " Tap Out" ??
Has anybody made well past 400 rear...M6 or added cubes with these as restrictions ?? Can a quality fuel pump allow a certain injector to produce a tad more power than traditional to it's sizing ??
Perhaps go ahead and brag if you can; who has made the most amount of SAE power using stock crap ??......

squalor

iTrader: (3)

I guess you've seen the Marren page. Their calculator says 369 hp at 80% but the math seems simplistic, it's not really an answer to your question.

HCI2000SS

iTrader: (2)

It just depends. For instance if you run a blower it will take more injector than n/a, and the LS6 intake can handle lots of power and boost as well but it will be restricted in a different way running n/a

Darth_V8r

iTrader: (4)

To answer your question about fuel pumps, the short answer is yes. GM fuel systems run at 58psi, but injectors are rated at 43 psi. So, you have to do some math to get from the injector "rating" to what they actually do in our cars.

So, if you run a higher fuel pump pressure you can cheat more out of the injectors. Cost is probably the same as just getting bigger injectors, and the injectors take less work to swap

kinglt-1

iTrader: (26)

I have seen setups make 420-440whp with the LS6 and stock 28.8 injectors, but the duty cycle is way up there. To stay under 80% dtc, would be around 390whp.

I would just upgrade to the white "gtp" injectors. They work great...I know you do not want to put that big of a injector in your car but really it's going to need it. I am at 71% dtc using them on my setup.

usdmholden

I made 480 rwhp with injectors rated 24 lb/hr @ 42 psi, but I wouldn't do it again given what is available now.

I was running near 100 psi of fuel pressure. This was back when the only injectors readily available were 24's and 30's, while 36's were really only aftermarket. The 42's didn't even exist yet as far as everyone knew. Aftermarket injectors back then were mega bucks and mostly low impedance, circa early-mid 1990's.

The sizing math is simple:

BSFC = brake specific fuel consumption, usually approx .5 lbm/(hp*hr) for NA
FPrated = the rated fuel pressure of the injector
FPsystem = the fuel pressure at which the system actually operates
Inj = injector size at rated pressure
DC = duty cycle in decimal format

hp = Inj/BSFC*8cylinders*square root(FPsystem/FPrated)*DC

So for my above numbers:

hp=24/.5*8*sqrt(100/42)*1.00

hp = 592

Not a good idea to run the injectors at such high pressures or 100% duty cycle, but 20-25 years ago, it was about the only option.

Most injectors can run pretty reliably through about 70 psi, they begin getting flaky around 80-85 psi.

edit - my response is for injectors only, obviously 5.0 Mustangs from the early 90's didn't come with LS6 intakes.

KCS

iTrader: (20)

FWIW, I made over 400whp with a junk LS1 intake so I would think an LS6 is capable of more, but I also used 42lbs/hr injectors