Adjusting knock sensor sensitivity going from a LS1 to LS7 block?
11-18-2010, 05:39 PM
#1
Safety Car
Thread Starter
Adjusting knock sensor sensitivity going from a LS1 to LS7 block?
Since switching from my stock LS1 engine to a forged LS7 engine, I have not seen any knock retard. The conversion harness that I used placed the stock LS1 sensors (located under the intake) to each side of the new block (normal LS7 location). With the LS1 I had to desensitize the sensors due to false knock. I returned the values to a stock LS1 for the engine change.
I have read the Ohms for the sensors, they are working in specifications. If I tap the side of the block with a hammer close to the sensors they detect it. I can even get the car to give a degree of knock retard if I hit the header flange with the hammer. Problem is I have to hit it pretty hard to actually get the retard.
Has anyone come up with values to make the sensors work better with engine swaps to the newer LS series? So far the advise I have gotten is adjust down until false knock shows up (with known good gas). Move the range back up until it all goes away and use that as a starting point.
I've never heard audible knock, the car is loud though..... I just don't feel 100% that the knock sensors will pick up detonation if it happens.
I have read the Ohms for the sensors, they are working in specifications. If I tap the side of the block with a hammer close to the sensors they detect it. I can even get the car to give a degree of knock retard if I hit the header flange with the hammer. Problem is I have to hit it pretty hard to actually get the retard.
Has anyone come up with values to make the sensors work better with engine swaps to the newer LS series? So far the advise I have gotten is adjust down until false knock shows up (with known good gas). Move the range back up until it all goes away and use that as a starting point.
I've never heard audible knock, the car is loud though..... I just don't feel 100% that the knock sensors will pick up detonation if it happens.
11-18-2010, 05:47 PM
#2
Melting Slicks
I would have suggested the "turn them down until they knock" method as well (although it does sound a little "down on the farm"..)
What are the ohm readings for an LS7 knock sensor? Perhaps that will give you a sensitivity ratio to start with. Or, what if you put in LS7 knock sensors?
What are the ohm readings for an LS7 knock sensor? Perhaps that will give you a sensitivity ratio to start with. Or, what if you put in LS7 knock sensors?
11-19-2010, 09:03 AM
#4
Le Mans Master
I have not adjusted mine and they do work in the LS7 location. I found this out while tuning. I added in some timing, got a little knock, and then backed the timing down.
11-19-2010, 09:35 PM
#5
Safety Car
Thread Starter
Had the car at the drag strip today and adjusted the sensors. I increased the table by 20% and the car showed all kinds of knock at 14degrees of timing and high 10 AFR using lots of meth. Safe to say the knock was false. Took the sensitivity back to stock values for now.
I'll try adjusting it a smaller amount in the future to see what happens. 20% is a lot....
I'll try adjusting it a smaller amount in the future to see what happens. 20% is a lot....
