MAX H.P. WITH 30LB. INJECTORS?

aod92 · Feb 22, 2007

I was wondering the max hp i can get with my 30 lb. injectors? The rest of the fuel system is a 255 lph intank pump,and a kirban regulator. I'm installing a master power 70mm turbo and looking to make around 550 rwhp. Would i be maxed out with the 30's or do i need to jump to 42's to be safe? The car also has ported tfs twisted wedge heads,anderson b31 cam and a trickflow intake with a bunch of other bolt on's Any help would be appreciated. Thanks!

millhouse · Feb 22, 2007

Without an FMU you'll be maxing out those 30lb injectors under 400 rwhp. 42lb injectors will be good up to 500-600rwhp depending on fuel pressure. The 42's will suit you fine but will leave no room to grow. Also be advised that if your still on the stock 5.0 block…your going to be walking on eggshells with that much h/p.

aod92 · Feb 22, 2007

millhouse said:
Without an FMU you'll be maxing out those 30lb injectors under 400 rwhp. 42lb injectors will be good up to 500-600rwhp depending on fuel pressure. The 42's will suit you fine but will leave no room to grow. Also be advised that if your still on the stock 5.0 block…your going to be walking on eggshells with that much h/p.

Its on a stockblock with a dss girdle. Dss tells me i should be safe to about 650hp. Does that sound right?

millhouse · Feb 22, 2007

aod92 said:
Its on a stockblock with a dss girdle. Dss tells me i should be safe to about 650hp. Does that sound right?

That sound about right for what they "claim". It isn't true however...and I wouldn't trust it to be reliable past 450rwhp. Once you start pushing it much past that it's a crap shoot with reliability.

Woodrow · Feb 22, 2007

aod92 said:
Its on a stockblock with a dss girdle. Dss tells me i should be safe to about 650hp. Does that sound right?

The only thing that girdle is going to do is hold the block together when it does split I say around 550 at the most.

jrichker · Feb 22, 2007

Injector HP ratings: divide flow rating by.5 and multiply the result by the number of injectors. This uses a 100% duty cycle. These ratings are for naturally aspirated engines.

Example:
19/.5 = 38, 38 x 8 = 304 HP
24/.5 = 48, 48 x 8 = 384 HP
30/.5 = 60, 60 x 8 = 480 HP

The preferred duty cycle is about 85% maximum, so for a safety factor multiply the final figure times .85.

304 HP x .85 = 258 HP
385 HP x .85 = 326 HP
480 HP x .85 = 408 HP

Remember that the above ratings are at 39 PSI. Increasing the pressure will effectively increase the flow rating. Example: a 19 lb injector will flow 24 lbs at 63 PSI, and a 24 lb injector will flow 30 lbs at 63 PSI.

See http://users.erols.com/srweiss/ to get the calculators used in these examples.

Metalcop · May 18, 2007

Does it hurt anything to have a bigger injector than necessary, so that you will have enough injector/duty cycle as you build your combination? Right now my car dynoed at 275 rwhp, so I am outside of my preferred duty cycle. I did the math, same equations as above, and my goal is 400 rwhp, eventually. I purchased 30# injectors to achieve this goal. Obviously, I don't need the 30#'s right now, but I will in the future. Driveability is my main concern, I'm hoping there will be no difference with the 30#'s, there will just be more duty cycle and lbs of fuel available, but not utilized?!

Daggar · May 18, 2007

It doesn't "hurt" exactly but does make low speed tuning for drivability a bit more difficult.

Metalcop · May 18, 2007

I have a PMS with the start up tunes from Anderson. All that is 'suggested' is to add timing (+6) at idle. No fuel subtraction, or changes made to air or idle control.

Here is my setup:

Stock block, heads intake
Vortech w/6lbs boost
65mm TB
Off-road exhaust, smog delete
19# injectors
Vortech FMU/19#
AFM Power pipe
3.55 gears

I am adding, today: (!)

30# injectors
recal FMU 30#
80mm MAF/30#
Adjustable FP regulator Aeromotive
Fuel pressure gauge
boost gauge
190 lph Ford fuel pump

Obviously, this is more than I need for my current setup, but I want to plan for the future, which included a good H/C/I package, looking for 400 rwhp (or slightly less) eventually, so I wanted to 'prepare' for these upgrades by building up my fuel/air delivery system. Rick Anderson has provided me a tune for after I install these upgrades. Again, idle is not really touched, just +6 for timing. Right now my car runs really well, I don't drive it too hard, and according to the PMS, my injector duty cycle is pretty low. Should I even bother with these upgrades or just hold off until I actually install the hci? Thanks!

BK_CAULEY · May 18, 2007

1 million H.P.

Metalcop · May 18, 2007

Thanks for your intelligent reply, that really helps me a lot!

BK_CAULEY · May 18, 2007

Metalcop said:
Thanks for your intelligent reply, that really helps me a lot!

your welcome. your question was already pretty much answered i just figured i would throw that in for laughs. guess it didnt work.

millhouse · May 18, 2007

100....................................BILLION..............................H.P. ?

BK_CAULEY · May 18, 2007

he is gonna flame you for that one. 1 billion ...that was so un-intelligent.

MAX H.P. WITH 30LB. INJECTORS?

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