False knock issues
01-09-2012, 11:16 PM
#1
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False knock issues Hey guys,
Quick background, 02 Z28 347 fully forged 8.5:1 CR single front mount PT88 running on 93 with meth injection
Just recently I’ve been getting false knock. It will occur in neutral free revving, or accelerating hard. It will jump to 4 degrees instantly then disappear. I have not changed anything in the tune so I started looking for the typical causes ( exhaust banging, etc) Found my poly motor mounts had melted, replaced them with solid motor mounts. All the exhaust is good, nothing close to the frame to be rattling, motor sounds fine no audible issues, car drives and pulls fine.
Attached is a few minutes of log and my tune(HPT), some WOT towards the end of the log and random free revving and accelerating hard.
Let me know what you guys think, thanks!
Quick background, 02 Z28 347 fully forged 8.5:1 CR single front mount PT88 running on 93 with meth injection
Just recently I’ve been getting false knock. It will occur in neutral free revving, or accelerating hard. It will jump to 4 degrees instantly then disappear. I have not changed anything in the tune so I started looking for the typical causes ( exhaust banging, etc) Found my poly motor mounts had melted, replaced them with solid motor mounts. All the exhaust is good, nothing close to the frame to be rattling, motor sounds fine no audible issues, car drives and pulls fine.
Attached is a few minutes of log and my tune(HPT), some WOT towards the end of the log and random free revving and accelerating hard.
Let me know what you guys think, thanks!
01-10-2012, 08:17 AM
#2
Are you sure it isnt BURST knock event from the massive change in airflow? Try removing that in your spark tables, and then see if it still is there.
Sometimes though, running solid motor mounts will transfer noise thru to the engine as well, so that "Might" be an issue as well. Can you not run poly again but run a heat shield around them?
Sometimes though, running solid motor mounts will transfer noise thru to the engine as well, so that "Might" be an issue as well. Can you not run poly again but run a heat shield around them?
01-10-2012, 09:30 AM
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It might be, although it was never an issue before. I can't run poly's as they will probably melt again, exhaust isn't even that close to them.
