Why fit a Knocklink when the ECU monitors knock through it's own sensor?
15 October 2003, 09:15 PM
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Just wondered as surely the ECU should detect knock a lot quicker than a human can?
Surely the knocklink tells you your engine is damaged!
Steve
Surely the knocklink tells you your engine is damaged!
Steve
15 October 2003, 09:24 PM
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the ecu can only advance/retard timing so much then you have no indication of knock occuring, thats what the knocklink does, alerts you and allows you to back off 
15 October 2003, 09:28 PM
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Well, there's low-speed knock (ringing bells -remember early 80's Ford Escorts 
- at low engine speed) which you can hear yourself and there's highspeed knock (at high rpm)....however this high-speed knock cannot be detected other than by a knock sensor which not only detects knock but also immediatly reacts by retarding the ignition timing thus preventing further knocking/damage....
- at low engine speed) which you can hear yourself and there's highspeed knock (at high rpm)....however this high-speed knock cannot be detected other than by a knock sensor which not only detects knock but also immediatly reacts by retarding the ignition timing thus preventing further knocking/damage.... 
16 October 2003, 07:14 AM
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Factory knock sensing is not that good once you start tuning. Changing the headers on a Classic will likely shut the thing up permanently - good thing too.....as long as you're also monitoring for knock
The new age STi's (and WRX's too I guess) are far more advanced, but you'd still be advised to have something in-car to tell you when something's gone wrong....once you get past simply raising boost a bit, anyway
Also bear in mind that knocklink's reacts differently on each car; it should really be checked with det cans so that you understand what is knock and what's not (in 'general' a slow rise in activity is engine noise, a brief spike is knock).
Richard
The new age STi's (and WRX's too I guess) are far more advanced, but you'd still be advised to have something in-car to tell you when something's gone wrong....once you get past simply raising boost a bit, anyway
Also bear in mind that knocklink's reacts differently on each car; it should really be checked with det cans so that you understand what is knock and what's not (in 'general' a slow rise in activity is engine noise, a brief spike is knock).
Richard
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16 October 2003, 11:05 AM
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Is there a DIY knock bargraph install, similar to the AFR circuit going around last year, to use the OEM sensor output at the ECU?
If it could work then this may show what's happening above the 5800rpm correction limit?
Nick
If it could work then this may show what's happening above the 5800rpm correction limit?
Nick
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