Draco

Hi guys.

I have a wet 100 shot kicking in at 3000 rpm, and a dry 75 shot coming on at 4200 rpm. I am getting sometimes 2-4 degrees of KR when the second stage kicks in. I have a wideband O2, and it reads a nice fat 11.5-11.8 AFR when the second stage hits, dropping to 11.2 at higher RPMs. I am running 22* timing with NGK tr6 plugs gapped at 0.35.

Any ideas on what could be causing this KR? It immediately decays after coming on, and I never get 2 KRs on the same pull. Does burst knock retard ever kick in based on sudden MAF reading changes (MAF reading jumps obviously when a dry shot hits), or just TPS changes?

Thanks!

Draco

OK, looks like Burst Knock. My grams/cyl load skyrockets when the dry shot hits which triggered the burst retard in both case I saw.

I'l leave the thread up in case anyone else wonder why they are seeing retard on a dry shot with rich AFR and low timing.

Chingon

iTrader: (1)

What's burst knock? (Still learning )

Draco

burst knock is basically the computer's way of automatically retarding timing to avoid knock before it happens. it does this when it sense a quick change in engine load. WHen you spray a dry shot this can happen since the MAF reads extra air and thus the grams of air/cylinder shoot up.

Chingon

iTrader: (1)

So wait, if it automatically retards timing to avoid knock, why does it show up as knock? Just because?

TT_Vert

iTrader: (12)

sorry to jump into this so late but how do you know if you have KR due to knock or just due to the burst knock table??

Dave