Caspers Knock Gauge vs Scanmaster 2.1


Still A Noob...
Mar 26, 2006
Today a couple of times at WOT the knock gauge went red yet the Scanmaster recorded no knock at all. I keep testing and the results were repeatable. After about 4 or 5 WOT runs the Scanmaster recorded a high of .7 knock.

What's going on here? Which is more reliable?

It's hard for me to tell if it pulling timing as I get off of it as soon as I see the red. Even if the Scanmaster was slower would it not eventually record more than .7 retard if the gauge is all red?

Excuse the lower level questions I've only had my Buick 18 months and definately still learning.
This is happening to me as well, I don't know if one is faster than the other. I thought they both read off of the same source...I know that when my alchy has ran out, the SM will definately register knock...the casper is just starting to appear to be just a flashing light. It goes off when the car shifts between 1st and 2nd at just normal speed. I think the hard shift (shift Kit) has caused this.
Overall, I think I need a powerlogger and to take the caspers out and replace the hole with an EGT gauge.:confused: