A while back I got an upper pulley and airraid intake installed, with a tune from RPM motors using HP Tuner. It dynoed at 540 at the wheels, which they said was a little high on average for a V with those mods on their dyno. The tune looked good and everything was copasetic. Then I noticed at high RPMs it seemed like it was pulling timing, it was losing power and it wasn't pulling hard to redline like it used to. I brought it back to RPM today for some troubleshooting, where we learned two things:
1. The tune was still dead on. A/F ratio still right on the money, and zero retard via knock sensor, so it wasn't detonating or pulling timing.
2. Higher up in the rev band we saw the injectors hit 104% duty cycle, which explains the power loss.
My next mod now is obviously higher flow injectors, but I wanted to post this here as an example of how little it takes to max out the stock injectors. With just the pulley and intake along with the tune, my engine wants to make more power than the injectors can keep up with. So it's a little bit of good/bad, bad that I'm running out of injector, but good that it's only the injectors, and not a MAF problem or a leak somewhere, or a bad tune or any number of a dozen other things.
Just keep it in mind when you start modifying, it seems like there's a real thin margin with the stock injectors.