VerdeZ28

KR-which i assume means knock retard, is going off under load. i saw this several times while running VCM scanner. I would like to know why is this happening. in my car it went up as much as 10* several times. on my bros mostly stock 02 Z28 it went off only once about 4*.

if i had to guess it could be since i basically have full bolt ons and never really tuned for it, could it be somewhat leaning out?

jimmyblue

iTrader: (11)

It's not unreasonable, long timing or short fuel (or a
false knock). Don't focus on how much, but rather
"why?". KR will overshoot for safety with stock settings.
Which makes debug a little more difficult (if you are
wanting to tune it up to the edge).

Look for an O2 voltage dip immediately preceding KR
as an indicator of short fueling; if it's fat but pinging
then timing wants pulled back; if it's always at a
certain RPM then consider motor noises (rocker minus
needles, bad / weak spring, etc.) as a possibility for
false KR. Or if you can hear anything banging.

VerdeZ28

KR peaked at 11.6* and just before this happened O2 sensors were at about 130-140mV. is this what you are talking about

im also noticing that KR goes up to around 3.5-4 at around 4500 rpm consistantly so that may be due to engine noise but the 11.6 KR happened at 2300rpm

VerdeZ28

could it be that the hypertech tune is calling for too much timing advance in this range?

sreve

iTrader: (3)

Most HyperTech tunes I've seen add some timing @wot and right at it, nothing excessive the rest of the table is stock along with PE.