brust knock retard vs knock retard help

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89 IROC CONV
Posts: 32
Joined: Sat Apr 03, 2010 6:26 pm

brust knock retard vs knock retard help

Post by 89 IROC CONV »

hello, can some explain the difference in brust knock retard and knock retard. and what needs to be done to disable them in $42. i see no way to tell which is which when data loging .im trying to tune a new mild sbc . im geting knocks in park and the engine has not been over 3000 rpm. runs ok in open loop which is a very short time. will not get over 20 mph in closed loop graps out. i took no short cuts on the motor the bottom end is all eagle and blanced from eagle. i dont hear any knocks motor has roller timing chain and comp cams gold roller rockers
mark m

89 IROC CONV
Posts: 32
Joined: Sat Apr 03, 2010 6:26 pm

Post by 89 IROC CONV »

would like to add cam is xe268h-14 which slams the valves closed could that cause knock's?
mark m

robertisaar
Author of Defs
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Location: Camden, MI

Post by robertisaar »

i believe it is different based on the mask, but i think burst knock is when the knock sensor picks up counts before hitting the minimum coolant temp to allow for knock retard.

or at least that's how it works with some masks.

89 IROC CONV
Posts: 32
Joined: Sat Apr 03, 2010 6:26 pm

Post by 89 IROC CONV »

thanks for the reply robert :)
mark m

yoda69
Posts: 31
Joined: Wed Dec 09, 2009 1:06 pm
Location: Australia

Post by yoda69 »

For some GM ECU's that I've looked at, the burst knock retard, is applied if knock is detected during tip in. For these if the engine speed is less than a threshold RPM and the TPS delta is increasing quickly then burst knock is enabled.

89 IROC CONV
Posts: 32
Joined: Sat Apr 03, 2010 6:26 pm

Post by 89 IROC CONV »

thanks for tip yoda 69
mark m

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