Miatav8,MstrASE,A&P,F wrote:
Thanks for the update.
In an open car where you may not be able to hear detonation, an oem knock sensor input to the ms is a great tool that can be used to dial it in as a gauge/red light and provide correction if you want. You have to set the threshold above normal running mechanical noises. An idle test should show the normal mechanical noise level. Your ms should accept the analog input directly. A gm unit is piper thread. You can lube the threads with antisieze but don't use teflon tape or anything to insulate the sensor from the block.
If you don’t have a knock sensor, I’d listen for det rattle with a dash display of very large kpa, tach, and wb02 while also logging. After warm idle check, perform casual normal driving kpa from 1.5k to 4k, followed by wot kpa to 4k. At any point in testing, if/as soon as you encounter any rattle, quickly note kpa, tach, 02 then let off.
Select the adjacent kpa (lighter load/numerically lower) at that rpm and hi lite the row out to max rpm.
Use the minus button to remove ½ degree from the row so each cell is changed ½ individually instead of smoothing/averaging the row.
Next, hi lite from each of those cells to 100kpa and smooth with the red crayon button. Select two columns at a time to smooth and do this out to max rpm.
Retest to duplicate rattle. If no rattles, perform the same tests to 4k but now use the next higher gear (3rd when you should be in 2nd) to pull from 1.5k, duplicating a steep hill.
I looked up the way Microsquirt see knock. You have to buy a GM spark module and run the knock to it then us the SPAREADC wire so the microsquirt can see it. Interesting there isn’t a direct hook up. I’ve never looked into this before. Thanks for the instructions. Pretty thorough write up here. Would be nice to have a knock sensor with a usb on it and send it right to the computer. I doubt something that easy is available. I’ll drive it first see how it is.