So you tune based on knock retard, not knock counts? With your current tune, around how many knock counts are you seeing in a short (say 30min) drive?

How quickly do you ramp up to your full 30°? As you can see on mine, I don't reach the full 34° until 4800 RPM, so at say 3200 I'm only at 27°.

Did you find that optimum AFR just by what was fastest at the strip? Did you play around with timing at all at the different AFRs?

My car's fairly loud, but not bad. The Corsa mufflers seem quieter than Magnaflows/Borlas/etc. It has a bit of a rattly noise at low RPM and high load, but I'm 90% sure that's just transmission noise (knock sensor doesn't pick anything up). I'd been running it on 91, but since I drove it out to the east coast I've been using 93 octane. I haven't been able to take it to the strip out here, but it seems to run the same. Looking at my datalogs, the occurrence of low-RPM knock doesn't seem to have diminished, and I was/am seeing WOT knock so infrequently it's hard to say if the 93 made any difference.

Actually, I'd forgotten that, but the low-RPM knock was there before I did the header swap.