DET cans: can't hear detination/knock when trying to purposefully induce it
#1
DET cans: can't hear detination/knock when trying to purposefully induce it
1995 Miata NA 1.6L ("90HP" EUDM), N/A, Speeduino 0.4.4b
I made some DET cans out of a mechanics stethoscope and vacuum tubing. I connected it to a threaded hole in the block above/between the oil pressure sender and oil filter. It seems to work quite well (or so I thought), I can hear the engine really well and very loud especially at high RPM.
But then I tried to induce detonation/knock to get a sense of what to listen for for later ignition timing tuning, and couldn't hear any difference. No pinging or crackling like I've seen in example videos.
My methodology was:
Second gear pulls WOT on an uphill 1000rpm to 3000rpm
Raised ignition advance from ~25deg to 50deg in the cells between 50kpa to 100kpa in 1000rpm to 3000rpm range.
I started at 35deg. didn't hear any pinging. Then progressively raised till 50deg- still nothing. I even tried 60deg...
Any thoughts much appreciated. Maybe I should connect it somewhere else on the block? The spot seems good, I can hear oil flowing, the engine roar, lifters aren't loud.
https://i.imgur.com/cfdJbtm.png
I made some DET cans out of a mechanics stethoscope and vacuum tubing. I connected it to a threaded hole in the block above/between the oil pressure sender and oil filter. It seems to work quite well (or so I thought), I can hear the engine really well and very loud especially at high RPM.
But then I tried to induce detonation/knock to get a sense of what to listen for for later ignition timing tuning, and couldn't hear any difference. No pinging or crackling like I've seen in example videos.
My methodology was:
Second gear pulls WOT on an uphill 1000rpm to 3000rpm
Raised ignition advance from ~25deg to 50deg in the cells between 50kpa to 100kpa in 1000rpm to 3000rpm range.
I started at 35deg. didn't hear any pinging. Then progressively raised till 50deg- still nothing. I even tried 60deg...
Any thoughts much appreciated. Maybe I should connect it somewhere else on the block? The spot seems good, I can hear oil flowing, the engine roar, lifters aren't loud.
https://i.imgur.com/cfdJbtm.png
Last edited by U2IK67NU1VLKJ0; 04-03-2023 at 04:18 PM.
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