I get knock as high as 7 counts when I am coasting (usually downhill) and then reengage into gear. I can make it smooth by trying to rev match or close to it or no rev matching and I almost always get knock. Here are two pics of the same log:





I've read numerous threads on tip in, but since I coast so much (saving gas?) on these long hills, I just want to make sure that I'm not actually knocking. I'm assuming it's phantom knock, but better to be safe than sorry. BTW, I have S2 cams and stage four Competition clutch, stock exhaust, Perrin intake.

So is this phantom or am I really knocking? The AFR's seem really high.

 

seems to me you're misfiring at that moment and knock sensor reads it as knock

 

Could be. I know I need to re-gap my plugs from blow out at high boost, but it doesn't seem to misfire at low speeds/loads. So this would be considered phantom knock if it's a misfire at low speeds/loads. I'll probably just raise my knock limits.

 

No clues but you do realise the ECU cuts fuel on decel.

 

Yeah, I do. I'm actually accelerating, increasing load. In the pics I'm coasting for a couple of seconds with car out of gear. When I put car into gear then release the clutch pretty smoothly it picks up knock. I'm assuming it's misfire or drive-train/valve-train noise.

 

I'm pretty sure it's phantom knock due to the clutch/drivetrain engaging. It is pretty noisy when down shifting.

 

not sure if i am reading the log correctly, but is your afr really lean? should it not be 15-1 or better?

 

I'm on E85, so it should be 17:1 at cruise/idle. It get's really lean at tip in and knocks and then is fine.

 

from what i have read those are cells (up to 160 or 180 load) that accel or tip in enrichment are active. would try adjusting those settings

 

I'll give it a shot. I up the units at 122 degrees and higher by 10 units. Thanks for the hint.