injector duty

[Allen fong]

Ok I am trying to help a friend install and tune his car with the 650 injectors i sold him,  setup: 2g big16g, 3" no cat, fp exhaust mani, ceddy mod big maps. The injector duty cycle is at 78% at 21 psi 230 load and 5k rpm. does this seem right? i don't have any old logs of my own to go back over. By the looks of this he's gonna run outta room soon? fuel trim low is at 2% and wot is 11.5 AFR. We did have some knock at 140-160 load around 3500-4500 rpm- fixed with timing. We also just left all the cells after 100 load to 11.5 after we setup the injectors.

Any input guys....thanks 

[Jason Harwood]

Is he running an OEM fuel pump?

[Allen fong]

Nope wal 255, rewired.

[Vlad Busta]

Is the fuel pressure set correctly?

[Allen fong]

its at 43.5 with vac hose off, well as close as i can tell the needle doesn't exactly stay in one spot.

[Jason Harwood]

its at 43.5 with vac hose off, well as close as i can tell the needle doesn't exactly stay in one spot.

I don't remember what I had my FPR set for with my 650cc's and 255wally.
But I never ran a high injector duty cycle.

I had a 95ECU with jeff o chip and S-AFC for tuning.

My AFR's were 11.7-12.1  under WOT and 14.7 under idle and no boost.

[Allen fong]

Once this white shit goes away i will post some new logs might help.

[John Hartman]

78% isn't that big a deal really.  11.5:1 af is close to ideal at higher rpm.

Work with the timing to get rid of the knock, and see if you can add a couple more psi boost.  If its well tuned and everything is working well, thats about it for a big 16g.  An Evo 16g will be able to get more out of it, but a big 16g is the least efficient of the commonly availiable 16g turbos.

[Allen fong]

Hey john

if I'm am logging a +/- .1 -.5 A/FR from what the map is asking is that considered ok or should the injectors be rescaled? most of the time its close .1 or .2 but not often band on! i am going to log in open loop and see if that changes just to insure I am not in closed loop at any time.

[John Hartman]

.5 is a bit off, but as long as your tune is good and on the safe side, and you are not tuned to the ragged edge on boost and timing it will be fine.