Tuning for water injection: fuel, ignition, and EGT

[SaabTuner]

Indeed. Sorry, I hadn't meant to imply that any amount of injectant had the exact same effect.

I only meant to say that when you do the tuning without WI, you'll need to re-adjust the timing. 5 degrees forward probably is a pretty good rule of thumb. I'm not sure how much water they were injecting in this study as they were just spraying a fine mist at the exposed throttle plates. The study focused on the Ion Sensing feedback controller, rather than the WI itself.

Cyllinder pressures should not change as long as your PPP stays at the same crank angle. WI does not affect the overal pressure curve (Rapid Burn Angle), but rather just delays the flame development angle, and thus delays the combustion.

Apologies for the oversized picture. ops:

Adrian~