LGTspecB1657615261 Posted December 2, 2009 Share Posted December 2, 2009 This log was a really short city drive with a couple of stops in the middle. It was between 45 and 50 degrees out. I had just done a 3rd gear pull, and was driving to my destination. I notice a lot of knock events. Many seem to be clustered right around when I am accelerating out of a dead stop. I have no high load knock events, and I do not knock on a 3rd gear pull. But I seem to have a decent amount while city driving, this log being an example. Should I be concerned?romraiderlog_20091201_182938.csv Link to comment Share on other sites More sharing options...
LGTspecB1657615261 Posted December 2, 2009 Author Share Posted December 2, 2009 Here is some city driving just prior to the 3rd gear pull. It would seem like there are less knock events. Do our cars have more knock when the TMIC is temporarily hot from a pull, heatsoak, etc?romraiderlog_20091201_182628.csv Link to comment Share on other sites More sharing options...
LGTspecB1657615261 Posted December 2, 2009 Author Share Posted December 2, 2009 anyone have thoughts or comments? Link to comment Share on other sites More sharing options...
Spec B Posted December 2, 2009 Share Posted December 2, 2009 From what I have read the false knock is a result of the sensor not being able to differentiate engine noise from true knock in the low rpm region...after 3000 rpm it gets pretty good at capturing knock. When I first installed my FMIC I was able to create a knock event just by moving around my charge pipes (they rubbed in certain areas) while idling...you could see knock sum increment every time I wiggled the pipes. I do not think it is heatsoak related. Link to comment Share on other sites More sharing options...
LGTspecB1657615261 Posted December 2, 2009 Author Share Posted December 2, 2009 From what I have read the false knock is a result of the sensor not being able to differentiate engine noise from true knock in the low rpm region...after 3000 rpm it gets pretty good at capturing knock. When I first installed my FMIC I was able to create a knock event just by moving around my charge pipes (they rubbed in certain areas) while idling...you could see knock sum increment every time I wiggled the pipes. I do not think it is heatsoak related. ok thanks. Its probably just coincidence that I had more knock after the pull. So far I am not seeing any knock in the high end, so I will just ignore all the junk that is showing up in the low end. Link to comment Share on other sites More sharing options...
Spec B Posted December 2, 2009 Share Posted December 2, 2009 FWIW, I get a ton of low rpm knock some days and almost none the next. I think the sensor is just whacky at low RPM...if your WOT runs are clean and you LV shows only low rpm (less than 2500-3000 rpm) learned knock, I would not worry too much about it. Link to comment Share on other sites More sharing options...
Boostin1657615274 Posted December 2, 2009 Share Posted December 2, 2009 what you're encountering is pretty common on a lot of cars. That's why interpreting engine sensors is a judgment call. On the search for a new DD... Link to comment Share on other sites More sharing options...
fishbone Posted December 2, 2009 Share Posted December 2, 2009 LGTSpecB, is your intake stock? Have you removed the intake silencer by chance? Link to comment Share on other sites More sharing options...
LGTspecB1657615261 Posted December 2, 2009 Author Share Posted December 2, 2009 100% stock down to the filter Link to comment Share on other sites More sharing options...
rtbrjason Posted December 5, 2009 Share Posted December 5, 2009 All this low load low rpm knock is very normal. I have the same car at stage 2 and see very similar results. I've done several long trips (same trip each time) logging knock sum and using pivot tables for each giant log file and see knock in almost all the same places each trip. I almost always get 120-140 knock events on this specific trip which is about an hour of highway driving. On each log the pivot tables looked almost identical with most all the knock showing up between 2400 and 3200 rpm and .3 to .9 load. At one point I removed 3 full degrees of timing in that whole area of my cruise and non cruise timing tables and took the same trip several times and the knock pivot tables looked identical to before making the timing changes. Link to comment Share on other sites More sharing options...
SubyShop.com Posted December 5, 2009 Share Posted December 5, 2009 I adjusted my map to ignore knock below 1 load. A lot of that is false positives and the knock that will cause damage happens during open loop. -Franz Link to comment Share on other sites More sharing options...
Spec B Posted December 5, 2009 Share Posted December 5, 2009 ^ me too (<0.85 load) Link to comment Share on other sites More sharing options...
CwhillVT Posted December 30, 2009 Share Posted December 30, 2009 Same here. I get a decent amout of chatter from my LFWF and ACT clutch, I had just been attributing it to that, not sure though. Link to comment Share on other sites More sharing options...
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