Wesmanw02

iTrader: (4)

My car is full bolt on, all internally stock. Stock 28lb/hr injectors. Had it dyno tuned a while back, and if I recall correctly, the tuner said the injectors were at 98% duty cycle. It put down 341WHP.

If anything over 80% duty cycle is basically means the injector is maxxed out, will I gain anything from upgrading to larger injectors?? And if so, what size would be reccommended??

ZL1Killa

iTrader: (17)

you will not GAIN RWHP or RWTQ, you will gain stability.

I would recommend 42# injectors at MAX. What do you have planned in the future? 150 dry nitrous? or wet? turbo? supercharger? what is your fuel pump as of right now?, still the stock one?

I would highly recommend 42# injectors and the racetronix PnP kit 255 fuel pump, the whole shebang including the HARNESS, as the stock wiring in our vehicles is not meant to take the current draw that this pump requires.

Wesmanw02

iTrader: (4)

Thats what I figured. However, if the injectors are near maxxed out at 98% duty cycle, is there potential that I'm losing power at higher RPM??

I don't currently have any other big plans for the car, probably at the most a mild cam. No nitrous or F/I as of now, there just aren't any kits that really appeal to me. If I was going F/I I would want a Roots or Twin Screw S/C, and currently there aren't really any options for that on our cars. So I don't think I need anything as big as 42lb/hr, you think 36lbs would be a good compromise??

Current fuel pump is bone stock. I checked the fuel pressure and its at 60PSI, needle pegs to 58PSI when revved and then jumps back to 60. I would like to be able to check it with a load on the engine while driving, but I don't have the means to do that.

So by more "stability" with the fuel pump and injectors, what exactly are you referring to??

ZL1Killa

iTrader: (17)

the stock fuel pump in its Liters/Hour rating, of course you can convert that to LB/HR of your injectors and equate to where your fuel pump maxes out.

I would recommend some 32# to 37# injectors rated at the typical 43.5psi.

On our car(s), they are actually 36.9# to 42.7# injectors

Honestly, I would go 32# and call it a day as LONG AS THE RATING ON IT IS 43.5psi.


by stability, I mean that your fuel pump is within your range of your fuel injectors such that you are not outflowing your fuel pump and watching your pressure drop...



AND if you go with the 32# injcetors you wouldn't have to change your fuel pump!
As in the chart the stock pump is good for 38# injectors, and you would be at 37# injectors(roughly) by using 43.5psi rated ones.