False Knock with custom tune and solid mm's/ stock trans mount
hope this might be of use to some of the people getting knock even though their afr's are in check. i was custom tuned with dsp and meth and was still getting some knock from 5k and up. i Was also running agp solid mm's but stock trans mount which caused a lot of vibration when car was at idle and a/c was on. Recently installed solid trans mount and 90% of vibration at idle with a/c on went away. the random knock at high rpm when WOT also went away. now i cant get the car to knock no matter how i try (with 100% meth), even at 12.5 - 12.8 afr. Obviously what i was seeing was false knock, possibly due to excess vibration since i was still on stock trans mount.. i would imagine that if car vibrated that much from a/c compressor at idle, that it was goin nuts at WOT throttle around 5k rpm.
Anyone wanna support or debunk this theory, please do so. Otherwise, if some of you are getting unexplainable knock and are running solid mm's and didnt do the trans mount, maybe this could explain your issue.
Hope it helps.
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Weird. Just seems like some cars are different than others. Mine have never knocked as a result of vibrations, even when I busted my lower motor mount and it was banging against the oil pan at the track. Guess 03 PCMs are a little less sensitive?
i was custom tuned with dsp and meth and was still getting some knock from 5k and up. i Was also running agp solid mm's but stock trans mount which caused a lot of vibration when car was at idle and a/c was on. Recently installed solid trans mount and 90% of vibration at idle with a/c on went away. the random knock at high rpm when WOT also went away. now i cant get the car to knock no matter how i try (with 100% meth), even at 12.5 - 12.8 afr. Obviously what i was seeing was false knock, possibly due to excess vibration since i was still on stock trans mount.. i would imagine that if car vibrated that much from a/c compressor at idle, that it was goin nuts at WOT throttle around 5k rpm.
Anyone wanna support or debunk this theory, please do so. Otherwise, if some of you are getting unexplainable knock and are running solid mm's and didnt do the trans mount, maybe this could explain your issue.
Hope it helps.
I suppose anything is possible but I'm highly skepticle of this type add-hoc of corelation.
The only true way to test it would be to reinstall the stock trans mount and see if the knock comes back.
Without a reaffirming test its just speculation at best.
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well yeah, at the moment it is just speculation, and i might swap the stock mount back in and see, just short on free time at the moment. Was hoping you would see this and chime in. just thought that maybe if i got the idea out there sooner, (before swapping mounts) someone else might be in the same boat and be able to do a little experimenting as well.
hope this might be of use to some of the people getting knock even though their afr's are in check. i was custom tuned with dsp and meth and was still getting some knock from 5k and up. i Was also running agp solid mm's but stock trans mount which caused a lot of vibration when car was at idle and a/c was on. Recently installed solid trans mount and 90% of vibration at idle with a/c on went away. the random knock at high rpm when WOT also went away. now i cant get the car to knock no matter how i try (with 100% meth), even at 12.5 - 12.8 afr. Obviously what i was seeing was false knock, possibly due to excess vibration since i was still on stock trans mount.. i would imagine that if car vibrated that much from a/c compressor at idle, that it was goin nuts at WOT throttle around 5k rpm.
Anyone wanna support or debunk this theory, please do so. Otherwise, if some of you are getting unexplainable knock and are running solid mm's and didnt do the trans mount, maybe this could explain your issue.
Hope it helps.
I don't want to offend, but we have seen this for the last 3 years. Between crap stock/aftermarket mounts and slipping clutches... we have seen more false knock in this car than any other car we have worked on. We have also seen improperly mounted/tq'ed knock sensors that have caused all sorts of grief for some of our S3 customers.
Now that you have the knock addressed , start to turn up the timing, you will really see some power gains by doing this.
110%, I even think that there are a few that have ID'ed a few mounts in the industry that have had problems with knock. Try a search for "knock and mounts". You should come up with a few threads about it.
well ive heard of downpipes with cutouts being a possible cause but i will look into the mount aspect of it. i just figured if idling with the a/c on can cause that much vibration, i can only imagine what the motor was doing when i was wot at about 6k rpm. I def think if you are going to do solid mm's, its all three or nothin!
well ive heard of downpipes with cutouts being a possible cause but i will look into the mount aspect of it. i just figured if idling with the a/c on can cause that much vibration, i can only imagine what the motor was doing when i was wot at about 6k rpm. I def think if you are going to do solid mm's, its all three or nothin!
You have to remember that the sensitivity from different RPM levels and boost levels are calcualted in the the knock sensors settings to determine what it knock and what isn't. Its not a "one" setting to detect knock, its a scalled chart. Hope that helps make more sense of the operating parameters.
So what does it all mean?! lol i am glad to hear that someone reputable agrees with my theory (even though i havent tested it........yet).I was also not aware that the knock sensor was scaled like that. Wonder what my cmr tune scale looks like? Anyone with the software wanna take a look?
i do want some input from you PTP, you mentioned something about turning up the timing now that i have corrected the knock issue. Without getting off topic on this thread too much, what do you think is "normal" timing with my e1 and 100% meth? i am only running 26* up top and always thought that seemed a little low for 100% meth. Maybe 26* is about all i can run, just wondering what you guys have experienced with modded stock turbos. i do know (in most cases) upping the boost will yield more gains than timing advance, but my boost is about as high as it'll go, sois there room for timing? Sorry to get off topic in my own thread. lol
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False Knock with custom tune and solid mm's/ stock trans mount
I def think if you are going to do solid mm's, its all three or nothin!
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