Burst KNock??
#3
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,604
Likes: 0
Received 6 Likes
on
6 Posts
When it sees a large step in cylinder air mass (which
follows MAP pretty much) it pulls back timing right
away rather than waiting to receive knock sensor
complaints.
The threshold for triggering is delta CylAir and if you
want to see this quantity, try using Excel (I don't
know if the custom PIDs will let you compute based
on previous frame values) as =(CylAir2-CylAir1)/8
for 10 frame/sec rate, /16 for 5/sec and /4 for 20/sec
(over 24 PIDs falls to 5/sec and under 12 will give you
20/sec frame rate). You can plot this in time and see
what the normal delta on throttle-mash is, and more
to the point you can look for opening-throttle events
that produce KR blips and figure out where to put a
BK threshold (if you prefer this to a fatter speed density
mixture than might be "proper" to cover the lean hole,
which is usually the real cause of tip-in knock).
follows MAP pretty much) it pulls back timing right
away rather than waiting to receive knock sensor
complaints.
The threshold for triggering is delta CylAir and if you
want to see this quantity, try using Excel (I don't
know if the custom PIDs will let you compute based
on previous frame values) as =(CylAir2-CylAir1)/8
for 10 frame/sec rate, /16 for 5/sec and /4 for 20/sec
(over 24 PIDs falls to 5/sec and under 12 will give you
20/sec frame rate). You can plot this in time and see
what the normal delta on throttle-mash is, and more
to the point you can look for opening-throttle events
that produce KR blips and figure out where to put a
BK threshold (if you prefer this to a fatter speed density
mixture than might be "proper" to cover the lean hole,
which is usually the real cause of tip-in knock).
#6
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,604
Likes: 0
Received 6 Likes
on
6 Posts
It should show both in a less-than-HO-table advance value
and in the burst knock retard PID. If it's active. I discovered
it by the former, working on a truck before the burst knock
retard PID was a scanner option (couple of years ago, now).
It does not show in the knock retard PID, it has its own
(and there are other retard PIDs too as I recall). If you have
a mysterious timing shortfall you should log all of the retard
and advance PIDs you can get ahold of and then discard the
ones that are always 0.
and in the burst knock retard PID. If it's active. I discovered
it by the former, working on a truck before the burst knock
retard PID was a scanner option (couple of years ago, now).
It does not show in the knock retard PID, it has its own
(and there are other retard PIDs too as I recall). If you have
a mysterious timing shortfall you should log all of the retard
and advance PIDs you can get ahold of and then discard the
ones that are always 0.
#7
Banned
Thread Starter
iTrader: (20)
Join Date: Feb 2003
Location: Fort Rucker
Posts: 607
Likes: 0
Received 0 Likes
on
0 Posts
I did Jimmy,
The only one showing any retard is the burst knock.
Correct me if I am wrong, but busrt knoc is a retarding device correct? If so why dosnt the retard pid show the degrees of burst knock present?
The only one showing any retard is the burst knock.
Correct me if I am wrong, but busrt knoc is a retarding device correct? If so why dosnt the retard pid show the degrees of burst knock present?
Trending Topics
#8
TECH Addict
iTrader: (10)
Join Date: Jun 2004
Location: Commerce Twp, MI
Posts: 2,918
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by yobabiesdaddy2001
I did Jimmy,
The only one showing any retard is the burst knock.
Correct me if I am wrong, but busrt knoc is a retarding device correct? If so why dosnt the retard pid show the degrees of burst knock present?
The only one showing any retard is the burst knock.
Correct me if I am wrong, but busrt knoc is a retarding device correct? If so why dosnt the retard pid show the degrees of burst knock present?