ok guys, what are you seeing for duty cycle on your injectors?

running some data logs on my car (08 GT 6spd) seeing 98% duty cycle. so looks like i need to get some bigger injectors. first off my question is what size injectors are stock?? and have any of you upgraded yours on NA applications, and what did you go to. also what are you guys seeing for duty cycle?

just loaded in my Uprev software and going to the dyno tomorrow for tuning, but if im maxing my injectors out already i dont know how much i can get out of her right now...

my specs

Vq35HR

UpRev
Stillen gen 3 long tubes
Stillen headers
aam test pipes
tomei catback (y pipe and rear section)
Walbro 255

 

That seems like a very high DC on such few mods. Your car probably puts down over 300 at the wheels though?

I was maxing out my injectors with 98-101 DC and ive upgraded to GTR 570cc injectors. I beleive a lot of my issue is my fuel pump its from 02 and has 200k on it.

Id be very interested in seeing what #'s you put down, as i though HR's had enough injector to support n/a mods easily.

My car isnt supporting my power lvl because im up about 100whp over what the car was in 100% stock form.

 

Stock injectors should be 335cc@3.5bar

What are you using for data logging?...UpRev (Cipher) I assume?

 

yes im using Uprev for logging. have a source through work for custom injectors, just not sure what sizing to get...

 

You might want to check fuel pressure, yes, that seems like a very high DC on such few mods.

 

idk if RWD HR injectors are 335. i doubt they are that small. considering these do 300whp fairly easily.

 

ill check fuel pressure, but have a brand new 255 walbro pump installed. anyone know if the pulse dampers ever go out on these?

 

At OEM fuel pressure the stock injectors are rated at 330cc, at standard fuel pressure they are 290cc.

FWIW, I see around 85-86% DC on my catback only car.