Knock sensor? LS2 block with LS1 computer
Bringing this thread back because subject is of interest to me. Can anybody verify that it actually works well to reprogram LS1 PCM for LS2 knock sensor? I know the idea is out there but I want evidence it works properly.
Can reprogramming be done with HP Tuner? That's what I have but I'm not familiar with it yet.
Can reprogramming be done with HP Tuner? That's what I have but I'm not familiar with it yet.
That is definitely peaking my interest and might provide the cleanest integration. Are there any drawbacks or loss of capability of a LS1 PCM that has been switched vs. the LS2 PCM made for the task?
I'm trying to figure out if it's a reasonable recreation of the LS2 technology or if the LS1 ECM has the identical capability but just not utilized in the Camaro. I'm not interested to do the switch myself (leave that to you) but I do want to understand what is done and how it behaves after the switch.
I'm trying to figure out if it's a reasonable recreation of the LS2 technology or if the LS1 ECM has the identical capability but just not utilized in the Camaro. I'm not interested to do the switch myself (leave that to you) but I do want to understand what is done and how it behaves after the switch.
There are 2 types of KS currently being used:
Both sensors use piezo-electric crystal technology to produce and send signals to the PCM. The amplitude and frequency of this signal will vary constantly depending on the vibration level within the engine. Flat response and broadband KS signals are processed differently by the PCM. The major differences are outlined below:
little more on the broadband single wire sensors
The PCM uses a KS in order to detect abnormal vibration in the engine, such as detonation, or spark knocking. Mounted in the engine block, the KS produces an AC signal at all engine speeds and loads. Next, the PCM adjusts the spark timing based on the amplitude, and on the frequency of the KS signal. The PCM calculates a normal level of engine noise, also known as the noise channel, from the KS signal. The noise channel consists of an upper and lower region. A normal KS signal should vary within the noise channel as shown in the Knock Sensor Signal - Normal. A KS signal outside the noise channel, as shown in Knock Sensor Signal - Knock Present, indicates spark knock. The PCM will then adjust the spark timing to eliminate the engine knock
Knock Sensor Signal - Normal
(1) Upper Noise Channel Region
(2) Noise Channel Average
(3) Knock Sensor Signal
(4) Lower Noise Channel Region
Knock Sensor Signal - Knock Present
(1) Upper Noise Channel Region
(2) Noise Channel Average
(3) Knock Sensor Signal
(4) Lower Noise Channel Region
- The broadband single wire sensor
- The flat response 2-wire sensor
Both sensors use piezo-electric crystal technology to produce and send signals to the PCM. The amplitude and frequency of this signal will vary constantly depending on the vibration level within the engine. Flat response and broadband KS signals are processed differently by the PCM. The major differences are outlined below:
- All broadband sensors use a single wire circuit. Some types of controllers will output a bias voltage on the KS signal wire. The bias voltage creates a voltage drop the PCM monitors and uses to help diagnose KS faults. The KS noise signal rides along this bias voltage, and due to the constantly fluctuating frequency and amplitude of the signal, will always be outside the bias voltage parameters. Another way to use the KS signals is for the PCM to learn the average normal noise output from the KS. The PCM uses this noise channel, and KS signal that rides along the noise channel, in much the same way as the bias voltage type does. Both systems will constantly monitor the KS system for a signal that is not present or falls within the noise channel.
- The flat response KS uses a 2-wire circuit. The KS signal rides within a noise channel which is learned and output by the PCM. This noise channel is based upon the normal noise input from the KS and is known as background noise. As engine speed and load change, the noise channel upper and lower parameters will change to accommodate the KS signal, keeping the signal within the channel. If there is knock, the signal will range outside the noise channel and the PCM will reduce spark advance until the knock is reduced. These sensors are monitored in much the same way as the broadband sensors, except that an abnormal signal will stay outside of the noise channel or will not be present.
little more on the broadband single wire sensors
The PCM uses a KS in order to detect abnormal vibration in the engine, such as detonation, or spark knocking. Mounted in the engine block, the KS produces an AC signal at all engine speeds and loads. Next, the PCM adjusts the spark timing based on the amplitude, and on the frequency of the KS signal. The PCM calculates a normal level of engine noise, also known as the noise channel, from the KS signal. The noise channel consists of an upper and lower region. A normal KS signal should vary within the noise channel as shown in the Knock Sensor Signal - Normal. A KS signal outside the noise channel, as shown in Knock Sensor Signal - Knock Present, indicates spark knock. The PCM will then adjust the spark timing to eliminate the engine knock
Knock Sensor Signal - Normal
(1) Upper Noise Channel Region
(2) Noise Channel Average
(3) Knock Sensor Signal
(4) Lower Noise Channel Region
Knock Sensor Signal - Knock Present
(1) Upper Noise Channel Region
(2) Noise Channel Average
(3) Knock Sensor Signal
(4) Lower Noise Channel Region
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
I have an 07 aluminum 5.3 and I relocated stock LS1 knock sensors running off an LS1 computer to holes already in the side of the 07 block. What should the new settings in the tune be? (I know they have to be more sensitive based on location change).
Very well. Thank you.
I've been looking around and I still can't find anybody who has been successful tuning an engine this way. Lots of examples of engine not running right and going back to LS1 knock sensor. Can you point me to some board members that made it work?
I've been looking around and I still can't find anybody who has been successful tuning an engine this way. Lots of examples of engine not running right and going back to LS1 knock sensor. Can you point me to some board members that made it work?
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Do you have a sample tune you would be willing to share?
I have copied tables from a 4.3 litter, but I know the sensitivity tables are way off. I had an issue last summer with a run that was way too lean and the LS2 style knock sensors did pull timing, but not enough... Damaged 2 pistons.
Thanks!
I have copied tables from a 4.3 litter, but I know the sensitivity tables are way off. I had an issue last summer with a run that was way too lean and the LS2 style knock sensors did pull timing, but not enough... Damaged 2 pistons.
Thanks!
TECH Resident
Joined: Aug 2005
Posts: 980
Likes: 2
Hate to bring this tread back but no one ever answered to real question and im about to put an ls7 in the camaro and i would like to run the right knock sensors and a racetronix conversion harness. Has anyone made this work right? do you need to re-pin like mentioned earlier in this thread. Hitech Tunes told me it shouldnt be a problem switching it over but i want to make sure people have done it and are not having problems
the LS2 style sensors will work....but you have to reprogram the sensor type in the tune, and you will have to wire one side of the sensor to a ground...
then you have to redo ALL of the knock tables...and its not a simple or easy task... lots of trial and error...
simpler to just stay with the stock LS1 one wire style sensors.
you can use the LS6 valley cover on an LS2 block with no issues.
neither sensor really works any better or any worse if tuned correctly...
then you have to redo ALL of the knock tables...and its not a simple or easy task... lots of trial and error...
simpler to just stay with the stock LS1 one wire style sensors.
you can use the LS6 valley cover on an LS2 block with no issues.
neither sensor really works any better or any worse if tuned correctly...
LS2 knock sensors are wired with a signal & low reference and the LS1/6 only has a signal circuit. I just drill out & tap the stock knock sensor mounting hole to 10mm & use LS1 knock sensors.
Then I go to the Knock Sensor Global Gain table and multiply the entire table by .9 at at time to increase the knock sensor sensitivity until spark knock is seen with sensible spark timing, then increase the table by 5%.
And an LS6 valley cover will not fit on a LS2 block.
Russ Kemp
Then I go to the Knock Sensor Global Gain table and multiply the entire table by .9 at at time to increase the knock sensor sensitivity until spark knock is seen with sensible spark timing, then increase the table by 5%.
And an LS6 valley cover will not fit on a LS2 block.
Russ Kemp
Staging Lane
Joined: Jan 2004
Posts: 93
Likes: 0
My guess and what we can do is to buy 2 of the 213-924 which are from the express van and copy the calibration over and sensitize accordingly. Repin the ECU apropriately. It could be done but you would need a keen ear or use the knock headsets to corroborate...
My concern is that the knock sensors and harness for the LS1 are extremely close to the headers.
My concern is that the knock sensors and harness for the LS1 are extremely close to the headers.
TECH Resident
Joined: Aug 2005
Posts: 980
Likes: 2
what would make the express van sensors better than lets say an ls7 sensor with a adapter harness? you can always wrap the header and harness if heat is a worry. Are the value for the 2 different types of sensors measured in the same units? Basically can you copy a factory file for that motor over and adjust from there? i know that forged internals leads to more noise and therefor would need different thresholds
Staging Lane
Joined: Jan 2004
Posts: 93
Likes: 0
what would make the express van sensors better than lets say an ls7 sensor with a adapter harness? you can always wrap the header and harness if heat is a worry. Are the value for the 2 different types of sensors measured in the same units? Basically can you copy a factory file for that motor over and adjust from there? i know that forged internals leads to more noise and therefor would need different thresholds
The LS2/3/7 knock sensors use different types of tables and might not be compatible with the express van/s10 data.
If you want to do this right you need the right approach and that is factory data with factory sensors with factory locations. Since not all 3 can be had at least factory data with the factory sensors can be used.
I doubt the racetronix conversion harness (which I have) works, since the pin to the ECU is different than the stock pins. Unless you only need to pin 2 wires, but I recall you need to repin all 4 wires (2/sensor).
the LS2 style sensors will work....but you have to reprogram the sensor type in the tune, and you will have to wire one side of the sensor to a ground...
then you have to redo ALL of the knock tables...and its not a simple or easy task... lots of trial and error...
simpler to just stay with the stock LS1 one wire style sensors.
you can use the LS6 valley cover on an LS2 block with no issues.
neither sensor really works any better or any worse if tuned correctly...
then you have to redo ALL of the knock tables...and its not a simple or easy task... lots of trial and error...
simpler to just stay with the stock LS1 one wire style sensors.
you can use the LS6 valley cover on an LS2 block with no issues.
neither sensor really works any better or any worse if tuned correctly...
I am trying this now and not having much luck currently. I bought the adapter harness from BP Automotive and have the grounds grounded to the block. Block is brand new and clean. I have the tune changed to flat response and have the sensors maxed out making them as sensitive as they can be right now. I have tried both pin locations, stock 11/51 and also 9/10 and have not gotten any response from the sensors when unfortunately I can hear audible knock from the engine at times under isolated conditions. I have a few more troubleshooting things to try to get them to read but just looking for feedback.
Do you have a sample tune you would be willing to share?
I have copied tables from a 4.3 litter, but I know the sensitivity tables are way off. I had an issue last summer with a run that was way too lean and the LS2 style knock sensors did pull timing, but not enough... Damaged 2 pistons. Thanks!
I have copied tables from a 4.3 litter, but I know the sensitivity tables are way off. I had an issue last summer with a run that was way too lean and the LS2 style knock sensors did pull timing, but not enough... Damaged 2 pistons. Thanks!
There was just a thread about this that I chimed in on within the last month. Long story short, no you will not have luck getting the 2 wire flat response sensors to work PROPERLY with the older Gen3 PCMs. Even editing tables directly that don't exist in any current editor to match what the other vehicles have that actually ran those sensors doesn't work properly. Sure it may detect knock once or twice and make you think it's working correctly but ultimately it doesn't and you can't log actual voltage levels or frequencies to "see" what the knock sensors are seeing to properly calibrate them anyways. The best bet is to just relocate the stock 1 wire resonant knock sensors and try to dial in the sensitivity tables, but again without being able to log levels that only gets you so far.
That’s what im beginning to see also. Sucks that it’s advertised by individuals/business’s that it works when ultimately and honestly it does not. I have one more thing I want to try on it when I get my truck back before i scrap the idea.
TECH Resident
Joined: Oct 2006
Posts: 993
Likes: 173
From: Euless, TX
There was just a thread about this that I chimed in on within the last month. Long story short, no you will not have luck getting the 2 wire flat response sensors to work PROPERLY with the older Gen3 PCMs. Even editing tables directly that don't exist in any current editor to match what the other vehicles have that actually ran those sensors doesn't work properly. Sure it may detect knock once or twice and make you think it's working correctly but ultimately it doesn't and you can't log actual voltage levels or frequencies to "see" what the knock sensors are seeing to properly calibrate them anyways. The best bet is to just relocate the stock 1 wire resonant knock sensors and try to dial in the sensitivity tables, but again without being able to log levels that only gets you so far.
Last edited by Fast355; Dec 13, 2024 at 05:49 AM.