2003 C5Z LS3 Swap Knock sensors
10-22-2023, 12:44 AM
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2003 C5Z LS3 Swap Knock sensors LS3 crate engine is going into a 2003 C5 Z06. A Lingenfelter 58x - 24x conversion box is being used along with the usual Racelogix conversion harness for injectors etc.
What is the scoop on knock sensors?
What is the scoop on knock sensors?
- Option 1 is apparently LS3 sensors can be used but then tuned in something like HP Tuners, but from what I gather this is PCM/OS dependent (AND possibly dependent on the 58x-24x signal conversion box?). Has anyone successfully done this with the 2003 PCM in HP Tuners?
- Option 2 is drilling and tapping the LS3 block for LS1 knock sensors but I fear I'm going to be running into some clearance issues with my long tube headers.
- Option 3 is machining down the threads on the LS1 knock sensors to an M8 thread. An LS1 M8 Knock sensor can be purchased- but possible clearance issues with headers.
- Option 4 is using a different M10 hole on the LS3 block- it kooks like one of the unused motor mount holes closer to the front of the block but how does this impact the knock sensor sensitivity? The sensors move to the side and based on what I've been able to research it sounds like the sensitivity needs to go up a bit.
- Option 5 is throwing said knock sensors in the garbage and hoping the gas station 93/94 and hot summer track days don't grenade my engine.
10-22-2023, 07:00 PM
#2
I'm in the same position but with a Dart LS-Next block. I'm more-or-less committed to making it work with the newer style sensors, but I've barely gotten started.
The car is getting dyno tuned in a couple weeks. I have Knock Ears on the car now, so we'll use those for tuning if the sensor change doesn't work out. With a little luck, we'll validate the sensors as we tune it. If not, I'll just experiment with them until I get them working.
I've found a handful of threads from people who say they've made it work, but I've seen very little specific guidance other than changing the sensor-type checkbox in the tune. Maybe that's all it takes, maybe there's more to it.
Some people say you need to wire both of the sensor grounds directly to dedicated pins on the PCM - and some say you don't. I'll be trying one wire per sensor at first because I have a wiring harness that connects them that way, but I'm prepared to switch if need be.
The car is getting dyno tuned in a couple weeks. I have Knock Ears on the car now, so we'll use those for tuning if the sensor change doesn't work out. With a little luck, we'll validate the sensors as we tune it. If not, I'll just experiment with them until I get them working.
I've found a handful of threads from people who say they've made it work, but I've seen very little specific guidance other than changing the sensor-type checkbox in the tune. Maybe that's all it takes, maybe there's more to it.
Some people say you need to wire both of the sensor grounds directly to dedicated pins on the PCM - and some say you don't. I'll be trying one wire per sensor at first because I have a wiring harness that connects them that way, but I'm prepared to switch if need be.
10-23-2023, 05:09 PM
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I'm in the same position but with a Dart LS-Next block. I'm more-or-less committed to making it work with the newer style sensors, but I've barely gotten started.
The car is getting dyno tuned in a couple weeks. I have Knock Ears on the car now, so we'll use those for tuning if the sensor change doesn't work out. With a little luck, we'll validate the sensors as we tune it. If not, I'll just experiment with them until I get them working.
I've found a handful of threads from people who say they've made it work, but I've seen very little specific guidance other than changing the sensor-type checkbox in the tune. Maybe that's all it takes, maybe there's more to it.
Some people say you need to wire both of the sensor grounds directly to dedicated pins on the PCM - and some say you don't. I'll be trying one wire per sensor at first because I have a wiring harness that connects them that way, but I'm prepared to switch if need be.
The car is getting dyno tuned in a couple weeks. I have Knock Ears on the car now, so we'll use those for tuning if the sensor change doesn't work out. With a little luck, we'll validate the sensors as we tune it. If not, I'll just experiment with them until I get them working.
I've found a handful of threads from people who say they've made it work, but I've seen very little specific guidance other than changing the sensor-type checkbox in the tune. Maybe that's all it takes, maybe there's more to it.
Some people say you need to wire both of the sensor grounds directly to dedicated pins on the PCM - and some say you don't. I'll be trying one wire per sensor at first because I have a wiring harness that connects them that way, but I'm prepared to switch if need be.
In the alternative, what about making a 90 degree mount out of aluminum and bolting that to the block? ICT makes and apparently they work. That would keep the knock sensor wires well away from the headers.