Knock and inconsistent AFRS at low boost (log included)

[Spoolingaround]

Whats up guys. Here's my issue. I keep seeing knock, even in 2nd gear, around mid range. Boost is set to only 15 psi and I see that my AFRs drop from 11:1 to 10:7 around 4.5k rpms, then it goes back to 11:0. Not sure if this is whats causing me to run a little richer here but that might be causing my knock (rich knock). This happens right around 247 sec in the log.

My maf comp is constant in the Hz ranges that this happens, so why would it all of a sudden run richer for a sec?

20g
272 cams
8.3:1 ross pistons.
850cc injectors dialed in

BLTed to 30 psi no probs. Verified mechanical timing etc etc.

 

[jon95dsm]

If you're shooting for 11:1 it looks like it just needs a little fuel taken out over 1000Hz across the board. Your pulls don't go all the way up so I can't really say past 5k. It's also going rich when you let off the throttle. There's not really a whole lot you can do to stop that entirely. Yours really isn't going that rich though. I've heard of some people having rich knock issues but you're at 10.7:1 where your knock shows up so I'd likely rule that out. Some threads on here talk about the knock sensor being overly sensitive, have you considered it not actually being knock? I imagine excess fuel on liftoff could ignite late or in the header and make it think you're getting detonation.

If you continue pulling does it still knock at that spot?