Thoughts on knock
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Thoughts on knock
Since putting in headers @ WOT with stock pulley I'm only seeing knock @ the shifts, is this false knock? Also because I have headers am I in a safe zone now that even running a 3.6" pulley wouldn't chip a piston? I know every car is different. When I ran the 3.6" pulley on a 50 degree day we had with headers I was seeing maybe 1.5* of knock or less @ WOT. I believe this is false knock but I could be wrong? Maybe I just need to be retuned to kill all the knock, but am safe for now?
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Since putting in headers @ WOT with stock pulley I'm only seeing knock @ the shifts, is this false knock? Also because I have headers am I in a safe zone now that even running a 3.6" pulley wouldn't chip a piston? I know every car is different. When I ran the 3.6" pulley on a 50 degree day we had with headers I was seeing maybe 1.5* of knock or less @ WOT. I believe this is false knock but I could be wrong? Maybe I just need to be retuned to kill all the knock, but am safe for now?
What other supporting mods? I run a 3.4 with the same SD headers, but that'* a Series 2 L67, CAI, hood vents, 180 t-stat, autlite 104'*, high flow 3" cat, and 2.5" exhaust. I run 19 degrees of spark advance at WOT with no KR.
The Series 3 3800 also has more aggressive timing tables. Might want to look into that as well.
#3
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Knock is never false. There is a reason for it, tuning or mechanical.
The more I've learned and listened about various things....I've learned so much about knock.
Knock can be introduced at shift points to lessen the power of the motor during the shift. This is part of torque management, aka programming that is in place to keep us from destroying our transmissions.
Going lean is typically what chips pistons. Tuning can do wonders for knock, power and potential issues.
One last thing to keep in mind is ..when it'* cold out the air is denser, therefore the cold helps us...but the denser air can cause us more problems. This is why with the same size pulley you can see more boost pressure in cold temps.
The more I've learned and listened about various things....I've learned so much about knock.
Knock can be introduced at shift points to lessen the power of the motor during the shift. This is part of torque management, aka programming that is in place to keep us from destroying our transmissions.
Going lean is typically what chips pistons. Tuning can do wonders for knock, power and potential issues.
One last thing to keep in mind is ..when it'* cold out the air is denser, therefore the cold helps us...but the denser air can cause us more problems. This is why with the same size pulley you can see more boost pressure in cold temps.
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Knock is never false. There is a reason for it, tuning or mechanical.
The more I've learned and listened about various things....I've learned so much about knock.
Knock can be introduced at shift points to lessen the power of the motor during the shift. This is part of torque management, aka programming that is in place to keep us from destroying our transmissions.
Going lean is typically what chips pistons. Tuning can do wonders for knock, power and potential issues.
One last thing to keep in mind is ..when it'* cold out the air is denser, therefore the cold helps us...but the denser air can cause us more problems. This is why with the same size pulley you can see more boost pressure in cold temps.
The more I've learned and listened about various things....I've learned so much about knock.
Knock can be introduced at shift points to lessen the power of the motor during the shift. This is part of torque management, aka programming that is in place to keep us from destroying our transmissions.
Going lean is typically what chips pistons. Tuning can do wonders for knock, power and potential issues.
One last thing to keep in mind is ..when it'* cold out the air is denser, therefore the cold helps us...but the denser air can cause us more problems. This is why with the same size pulley you can see more boost pressure in cold temps.
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I'm seeing 8-9PSI with the 3.8" Pulley on in 20-30* weather. Call me nuts but my aeroforce is reading advanced ignition spark of like 40 generally? Is this normal? I'm running Autolite 104 Iridium XP'*, could this be my potential unfriendly knock source? I've heard that running copper is better, but I wanted long life from the plug.
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I'm seeing 8-9PSI with the 3.8" Pulley on in 20-30* weather. Call me nuts but my aeroforce is reading advanced ignition spark of like 40 generally? Is this normal? I'm running Autolite 104 Iridium XP'*, could this be my potential unfriendly knock source? I've heard that running copper is better, but I wanted long life from the plug.
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Well seeing that I don't have a tuner myself, I don't get to view these things very often:(. I did see my spark table, etc in fall but that was when I was running 3" Downpipe and not headers. I couldn't remember the values of what I was running then, and from the posts here it sounded like 40 was "high".
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Here you go anyway. Here'* an example of a spark table in hptuners.
Spark is determind based on airmass at a given engine RPM. Airmass is determined by your MAF sensor and to some degree, your MAP sensor. Your spark changes across the table. Under cruising, spark is advanced quite a lot in order to increase fuel economy.
Now, the spark table'* numbers are not final. There are modifiers in the tune where if some conditions are met, the spark changes. For example, if manifold temperature exceeds a certain threshhold, all spark will be retarded by a given amount. The opposite is also true, such as spark advance when the EGR valve is opened.
Spark is determind based on airmass at a given engine RPM. Airmass is determined by your MAF sensor and to some degree, your MAP sensor. Your spark changes across the table. Under cruising, spark is advanced quite a lot in order to increase fuel economy.
Now, the spark table'* numbers are not final. There are modifiers in the tune where if some conditions are met, the spark changes. For example, if manifold temperature exceeds a certain threshhold, all spark will be retarded by a given amount. The opposite is also true, such as spark advance when the EGR valve is opened.
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