Adding a knock sensor to MS??
#23
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If you have an NB8B or NB8C you don't need the KnockSense. Just follow the instructions and build this circuit:
http://megasquirt.sourceforge.net/extra/knock.html
Works like a charm on my NB8C!
http://megasquirt.sourceforge.net/extra/knock.html
Works like a charm on my NB8C!
#25
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If you have an NB8B or NB8C you don't need the KnockSense. Just follow the instructions and build this circuit:
http://megasquirt.sourceforge.net/extra/knock.html
http://megasquirt.sourceforge.net/extra/knock.html
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Can you share the knock sensor output with the stock ECU?
#28
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I datalog anytime I drive around since I have the incar pc. Yes there is knock and yes the knock sensor shows it. I can hear it, place a marker in MegaTune and when later on I check the logs in MegaLogViewer, I can see the knocks.
#29
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This is off-topic, but how do you place a marker in MT? Never heard of that.
On topic, here is an interesting thread on knocks sensors: http://www.corner-carvers.com/forums...ad.php?t=32308
#33
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So, I've been doing a bunch of reading and wanted to pass on an idea for this. The Saab APC has an output that is grounded when knock is detected. All the MS needs is signal like this to detect knock. Advantages to this are:
-The APC is tuned to the specific sensor used. Less chance for false alarms.
-The APC box has an RPM input, which it modify it's sensitivity at higher RPMs. Once again less chance for mistakes.
The APC also can control boost, but that's a different story.
The modifications to the MS would be a 470R to 2kR 5V pullup resistor and bringing the signal in from the DB37.
I've got a snowboard-busted up knee, so I won't be able to make it out to the junkyard for a while. Thoughts?
-The APC is tuned to the specific sensor used. Less chance for false alarms.
-The APC box has an RPM input, which it modify it's sensitivity at higher RPMs. Once again less chance for mistakes.
The APC also can control boost, but that's a different story.
The modifications to the MS would be a 470R to 2kR 5V pullup resistor and bringing the signal in from the DB37.
I've got a snowboard-busted up knee, so I won't be able to make it out to the junkyard for a while. Thoughts?
#35
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The APC box does the sensor signal conditioning. The APC box is a stand alone with the appropriate knock, pressure sensor and boost solenoid. It is a very common swap on volvos. It does not need the Saab ECU. It's real purpose is to reduce boost when knock is sensed. It could control boost in our application also, but you have to add a pressure transducer and a few more wires.
http://www.pbase.com/740atl/apc_installation
http://www.pbase.com/740atl/apc_installation
#40
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I talked to a Motec guy, who should know what he was doing tuning those WRC cars and he pretty much downplayed knock sensor saying that every time they change something in the car, the frequency the sensor looks for when knocking changes too and that causes a lot of false alarms or overreacting. And they do test a lot, even different exhaust changed the way knock sensor worked.
He did not treat knock sensor as tuning device, more like a suggestion.
hrk
He did not treat knock sensor as tuning device, more like a suggestion.
hrk