Knock related question

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Wiggles93
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Knock related question

Post by Wiggles93 »

Hi guys been playing with my vy l67 , seems im detecting knock at almost every fast gear change (manual) and when I blip the throttle but not under load or high rpm, could this just be mechanical noise? Doesn't (seem) to knock under load or high rpm , should I just pull more timing till it stops or
Is there a good way to check without buying knock ears?

Vy almost stock l67 running flash na computer
Shhh, it hasn't broken yet
immortality
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Re: Knock related question

Post by immortality »

Is it a stock L67 bin modified to suit the flash pcm?
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vlad01
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Re: Knock related question

Post by vlad01 »

probably false knock (mechanical noise) , real knock happens under high load WOT and high rpm. Quite rare for it to happen outside of those conditions.

knock ears is the only way to confirm and in my experience the factory knock detection is hit and miss at best, false knock counts and no knock counts where there is real knock, in fact I have not yet seen a real knock event correlate with detected event.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
immortality
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Joined: Thu Apr 09, 2009 12:31 pm
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Re: Knock related question

Post by immortality »

I noticed similar knock on our L67, mostly on throttle tip in which is why I believe the L67 tunes have fairly aggressive burst knock settings.
Wiggles93
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cars: Vy S pac manual daily
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Re: Knock related question

Post by Wiggles93 »

The tune is one I've made up with a fair bit stolen from a l67 tune, I can post it up if it helps anyone.
I'm glad to hear it could just be mechanical noise, I had been pulling timing with no noticeable result's and was starting to worry, I'll look into burst knock settings and perhaps some decent knock ears funds permitting
Thanks heaps for the replies
Shhh, it hasn't broken yet
vp304
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Re: Knock related question

Post by vp304 »

Hey immortality i have noticed on my l67 swap i am only getting burst knock when doing 80kph and torque converter is locked and i go to accelerate away. Was this something similar to what you were getting ?
I do not notice knock anywhere else. And i can hear the knock at this point for like a split second and the factory knock sensor picks it up also ?
immortality
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Joined: Thu Apr 09, 2009 12:31 pm
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Re: Knock related question

Post by immortality »

When you upgrade the pulleys and bring in more boost sooner/lower rpm/less TPS you need to get the engine into PE sooner or the engine will be producing boost but the PCM is still staying on closed loop mode which is too lean when the engine is making boost.

If you are only seeing knock with the converter locked and the engine coming under load/boost adjust the TCC settings to release TCC lock so the engine can accelerate.
vp304
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Re: Knock related question

Post by vp304 »

Thanks immortality will look into tcc unlock settings as it is a bit lazy to unlock say when doing 80 plus kph and you just want to pass someone on freeway etc
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