Is KR Easy To Spot on Dyno Graph?
Thread Starter
TECH Resident
Joined: Jan 2002
Posts: 956
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From: Phoenix, AZ
Is KR Easy To Spot on Dyno Graph? Just wondering . . . my PCM thinks my sensors are not working ( p0327/p0332 ) even though I've replaced both of them. I may be stuck tuning by ear until I get this figured out ( don't know what to do next ).
So if the car starts getting KR, can it be seen easily on a graph? Can you guys hear it on the dyno?
- Dug
So if the car starts getting KR, can it be seen easily on a graph? Can you guys hear it on the dyno?
- Dug
You can hear pinging if it's bad enough. KR is supposed
to suppress it (what is the sound, of one hand clapping?)
and you would probably not see it if the dyno rolls up
slow; if the KR is applied evenly, it may in fact be holding
you at MBT and maximizing output. But KR is better at
maintaining steady-state operation at ping threshold
than it is at dealing with changing load conditions, its
time constant (on the go-away side) is pretty slow.
Ideally you would be running a logger during dyno pulls
to see what's what, and what wants tweaking. Here you
could get KR data.
to suppress it (what is the sound, of one hand clapping?)
and you would probably not see it if the dyno rolls up
slow; if the KR is applied evenly, it may in fact be holding
you at MBT and maximizing output. But KR is better at
maintaining steady-state operation at ping threshold
than it is at dealing with changing load conditions, its
time constant (on the go-away side) is pretty slow.
Ideally you would be running a logger during dyno pulls
to see what's what, and what wants tweaking. Here you
could get KR data.
Thread Starter
TECH Resident
Joined: Jan 2002
Posts: 956
Likes: 0
From: Phoenix, AZ
Thanks . . . the only problem with trying to log it is my PCM think's they're fried, so no data . . . I had to turn them off in Edit or the PCM pulls 4 at WOT no matter what. So I'm tuning by ear . . .
Full time 4 degrees of KR sounds like the '98 model year
"we'll get it right later" knock sensor syndrome. Might
look into that, if you have never replaced the originals.
"we'll get it right later" knock sensor syndrome. Might
look into that, if you have never replaced the originals.
Thread Starter
TECH Resident
Joined: Jan 2002
Posts: 956
Likes: 0
From: Phoenix, AZ
Yea, I have replaced them . . . didn't make any difference at all. I'm considering getting my PCM reflashed at the dealer ( never done it before ) and then putting my Edit changes back in manually. I'm at the end of my rope, I think I'm going to have to tune this thing by ear!!
- Dug
- Dug
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TECH Fanatic
Joined: Nov 2001
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From: Corona CA
KR looks like step in the graph and it continues it's normal shape. Kinda like the printer skipped.
You WILL get more KR on the dyno than at the track from my experience. Allow 2 deg on the dyno, and you should be OK. 4 deg will show on the street slightly and intermittently.
You WILL get more KR on the dyno than at the track from my experience. Allow 2 deg on the dyno, and you should be OK. 4 deg will show on the street slightly and intermittently.
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are you sure your getting continuity with teh knock sensors and they are plugged in? sometimes a bad tune will pop a knock sensor code, althoguh i never seen them pull much timing at all
If they are turned off you will not have any knock retard (you already knew that.)
So you will be seeing detonation on the graph which is easy to see. If your Dyno operator knows anything at all, he/she will be able to show you the detonation on the graph.
It will look like something like this in the area where the detonation is happening -> WVvVvWVWvWV
So you will be seeing detonation on the graph which is easy to see. If your Dyno operator knows anything at all, he/she will be able to show you the detonation on the graph.
It will look like something like this in the area where the detonation is happening -> WVvVvWVWvWV
