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getting some KR on takeoff??

Old 05-30-2005, 08:15 PM
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Default getting some KR on takeoff??

went out for a ride tonight and i noticed in the log i got some KR in forst gear when taking off, looked like the speed was spikey so i figured it has something to do with wheel spin. traction was turned off so i dont really know what the deal is with this. i got it 2 times and it was on 1st gear take off, not really even that hard, and i noticed mph fluctuating a good bit.

i dont know if this has something to do with the timing tables or not, but this is the second run after the cam and heads have been installed so im just wondering if maybe it could be VE related becuase its really rich, or if its just from the quick changes from wheel spin to hook up. dont know if i should adjust the burst knock up at all or not. what do you guys think?
Old 05-31-2005, 11:01 AM
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I get 2.3 to 2.7 degrees of knock,but only on a dragstrip launch in 1st gear,none in 2,3
or 4th.Wish I knew what causes it also.
Old 05-31-2005, 03:52 PM
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to the top
Old 05-31-2005, 03:59 PM
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Sounds like burst knock.
Old 05-31-2005, 04:22 PM
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thats what i was thinking, maybe just rapid map changes from wheel hop or somethign? how would i go about adjusting this, i have never had to deal with this
Old 06-01-2005, 12:04 AM
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I thought that burst knock was a separate pid from kr and that it would not show unless you're specifically logging it.
Old 06-01-2005, 04:49 AM
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hmmm im not sure, anyone else?
Old 06-01-2005, 07:55 AM
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It is pretty easy to set off the knock sensors. I wouldn't be surprised to see a hard launch do it; your motor torques over pretty hard with the initial tire hit. All kinds of stuff sets off the sensor: wheel hop, rough road, exhaust rattle, etc....

An easy way to tell if it was just an initial shock that upset the knock sensors is to log and trend it. If it just a spike which continues to 0 with a steady linear trend, then most likely it is just the launch jarring the motor.
Old 06-01-2005, 03:48 PM
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well the only times i had it was with some slight wheel hop on take off, those were the only time i had hop and the only times i saw kr


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