Gernby

I just replaced the scan of the dyno plot with a better image (at the top of the thread).

twohoos

This is kinda perplexing. One thought: Were you adjusting the VAFC setting solely based on air-fuel, or were you using power gains as the basis? I ask because, as UL points out, adjustments made at one rpm affect how the ECU behaves at other rpms, so even if there's no net change in AFR, there could be a change in power. Conversely, you may end up with a nonzero VAFC setting in order to maintain the original AFR.

Example: my car! (Tuned by UL.) We went for power gains first, and only concerned ourselves with air-fuel if the ratio got too lean. In fact, below VTEC, we ended up with gains with no real change to AFR, and we found that leaning it out there actually produced a drop in power.

AFR before-after:

TQ-HP before-after:


Don't have my settings handy, but they are in the old VAFC settings archive thread.

Gernby

Those are really nice plots! I wish I lived near enough to UL to let him do the tuning!

I tuned for AFR, and didn't really look at the power. Maybe I should go back to the dyno.

Pinky

[QUOTE]Originally posted by gernby
[B]Those are really nice plots!