Good idea?

[MichBC3]

I currently have 55 lb injectors in my engine and an Accel GEN7 ECM. Last year (with a cat converter) by tuning A/F and spark, I was able to pass emissions at 15 and 25 mph on a rolling dyno. It was pretty tough, but I did it.

I was thinking that when I have to do this again some day, maybe I should change to 28 lb/hr injectors and of course re-adjust the GEN7 to accomodate the change. Was wondering if the smaller injector would conceptually make it easier for me to tune to pass. Whaddaya think?

 

[norbs]

It depends if the Base PW is less than the injector opening dead time, then the injector may be a little it erratic in spray pattern. Otherwise I don;t think its going to make much difference. Are you using a wideband o2 on the car?>

 

[MichBC3]

PW with 55 lb injectors at idle is only 1.2 ms I think, sometimes going to 1.0. I will have to confirm that number when the weather warms up enough to start and drive the car again.

Yes, currently using an AEM 30-4100 wideband gauge controller in closed loop with the GEN7. I am not all that happy with the AEM setup and plan to replace it with an Accel wideband soon. A/F on that guage at idle looks something like 14.2, 14.3, 14.2, 14.2, 14.3, then out of nowhere it jumps to a single reading of about 16, then back to 14.2, 14.2, 14.3, etc. Seems to have that wacky lean reading about every 8th or 10th display. I can't explain that. Maybe there is a feedback loop/incompatibility with the GEN7. Also, the AEM gauge may read 14.2, but the output voltage from it does not match. So there is an offset or difference of 0.2 A/F ratio between what the gauge says and the Accel Gen 7 reads. I called AEM about it. They said that was typical and suggested that I buy an AEM DFI ECM setup because you can adjust the offset. Sure..!