GM knock sensor thread Options

[Fastbird]

And another thing . If GM sensors are narrow band sensors, then why can I loosen my valve lash and create knock that gets picked up by the sensor??? Why can I swap from a stamped steel rocker to a full self aligning roller rocker and get knock?? Why can I have a long tube header merge collector tapping on a crossmember and cauing the knock sensor to do it's thing?? Why do you have to completely disable the knock system when converting to a solid roller valvetrain? You can't possible say that the knock sensor will only pick up on a single frequency based on the bore of the block when so many outside the bore items will set it off.

your are such a domestic guy...lol the 3s dosnt have rockers or long tube headers.

Awww come on now, don't hate on me for being an import newb. You know what I was pointing out.

Ummmm.......I thought it was stated that the J&S and MSD both used the GM knock sensor.

Im not talking about just the sensor. Both companies sell a device which, unlike 3sgte ecu, was ment to work with GM sensor. I believe that J&S retards timing through the device, not through the ECU. Another thing is that GM sensor being able to pick up different frequencies (being wideband) can interpret signals that ECU does not understand, unlike these "knock monitor" devices.

Ok, now I follow ya.

[lagos]

now we get to the real truth ... you just want to be able to say you have a GM part on your car ! hahahaaha j/k

[Defgeph]

Whats all this fear of a knock sensor ? Who has ever blown one on this site ? I'm going to agree with the Art, Manny, Jay, Justin and all the rest of the swappers.

Sometimes threads at MR2Oc should stay there. These guys are running 300 to 400 HP 3sgte's. A basic run of the mill swap with some fuel upgrades is not going to blow sensors all the time. My sensor was made in 91 or 92, it still works fine.

Stick with all Toyota parts. The more non Toyota parts you put into this car, the more trouble you have later on.

You have to remember Shops are there to get the job done, no matter what parts they have to use. They have to keep the costs down to make the most money. So using a cheaper alternative is always thier answer. This is a project you cannot cheap out on.


Not trying to offend anyone Just my P.O.V.

[scothaniel]

Just to add to the heated fun here.

I had a stock Toyota knock sensor on my All-trac with a Link Plus EMS. The EMS let me see the knock counts in nice pretty graphs, and under heavy boost I was seeing a ton of knock - tuning was in order.

Anyways, I went through 2 knock sensors in as many months, then I switched over to the GM knock sensor. Same knock counts, but the sensor held up. A couple months later and the motor crank-walked due to bad machining. Regardless, the GM sensor had worked fine.

So, I recently installed the GM knock sensor on the 3rd gen powered 6GC, and I started getting code 52 on the stock 205 ECU. Switched back to a stock knock sensor and it cleared up. Checked the EPC and the part numbers for the 3rd gen 3S is different then the 2nd gen.

[lagos]

Just to add to the heated fun here.

I had a stock Toyota knock sensor on my All-trac with a Link Plus EMS. The EMS let me see the knock counts in nice pretty graphs, and under heavy boost I was seeing a ton of knock - tuning was in order.

Anyways, I went through 2 knock sensors in as many months, then I switched over to the GM knock sensor. Same knock counts, but the sensor held up. A couple months later and the motor crank-walked due to bad machining. Regardless, the GM sensor had worked fine.

So, I recently installed the GM knock sensor on the 3rd gen powered 6GC, and I started getting code 52 on the stock 205 ECU. Switched back to a stock knock sensor and it cleared up. Checked the EPC and the part numbers for the 3rd gen 3S is different then the 2nd gen.

the important thing to note is that you were using an ems that is designed to work with just about any type of knock sensor, unlike the stock ecu .

[Fastbird]

now we get to the real truth ... you just want to be able to say you have a GM part on your car ! hahahaaha j/k

SSSSSSShhhhhhh!!!!! You're the only one to figure it out so far.

[Fastbird]

Just to add to the heated fun here.

I had a stock Toyota knock sensor on my All-trac with a Link Plus EMS. The EMS let me see the knock counts in nice pretty graphs, and under heavy boost I was seeing a ton of knock - tuning was in order.

Anyways, I went through 2 knock sensors in as many months, then I switched over to the GM knock sensor. Same knock counts, but the sensor held up. A couple months later and the motor crank-walked due to bad machining. Regardless, the GM sensor had worked fine.

So, I recently installed the GM knock sensor on the 3rd gen powered 6GC, and I started getting code 52 on the stock 205 ECU. Switched back to a stock knock sensor and it cleared up. Checked the EPC and the part numbers for the 3rd gen 3S is different then the 2nd gen.

Good info. Maybe it won't work with the 3rd Gen. I'll be running a 2nd Gen so it shouldn't be a problem, but we'll see as I like to do datalogging. Of course, no knock or knock retard would be optimal.

[scothaniel]

the important thing to note is that you were using an ems that is designed to work with just about any type of knock sensor, unlike the stock ecu .

The Link EMS is actually engine specific to accomidate the stock sensors. Since I had the same knock count reading with both sensors (90-120 counts). its pretty safe to say that the knock sensors put out the same A/C voltage signal.

This post has been edited by scothaniel: Jul 12, 2006 - 2:20 PM

[jgreening]

the important thing to note is that you were using an ems that is designed to work with just about any type of knock sensor, unlike the stock ecu .

EMS or stock ECU shouldn't matter. The knock sensor picks up the frequency emitted due to the bore of the cylinder and then just sends a signal to the ECU or EMS that knock is occuring.

The bottom line is that the GM sensor will see some of the knock, just not all of it. I think it could actually be effective at getting more power out of a car because you will get knock retard less often. We have discussed ad nauseum whether that is a good idea....

[Dr_Tweak]

Just to add to the heated fun here.

I had a stock Toyota knock sensor on my All-trac with a Link Plus EMS. The EMS let me see the knock counts in nice pretty graphs, and under heavy boost I was seeing a ton of knock - tuning was in order.

Anyways, I went through 2 knock sensors in as many months, then I switched over to the GM knock sensor. Same knock counts, but the sensor held up. A couple months later and the motor crank-walked due to bad machining. Regardless, the GM sensor had worked fine.

So, I recently installed the GM knock sensor on the 3rd gen powered 6GC, and I started getting code 52 on the stock 205 ECU. Switched back to a stock knock sensor and it cleared up. Checked the EPC and the part numbers for the 3rd gen 3S is different then the 2nd gen.

It's nice to see someone post in this thread that has some real life experience with both sensors and isn't just repeating things that they read on an internet forum. Great info, thanks very much!

That's interesting that the third gen knock sensor is different.

-Doc

[jgreening]

It's nice to see someone post in this thread that has some real life experience with both sensors and isn't just repeating things that they read on an internet forum.

I agree although I will add that reading it on an internet forum and repeating it is better than providing incorrect information regardless of it source.

[scothaniel]

Always happy to share my experiences with others - just wish it wasn't on I managed to break things. Here's another valuable lesson - never leave a wrench on top of the motor when the timing belt cover is off!

[Rjb23]

I'm running the GM knock sensor and have had zero problems out of it. I also have yet to see anyone test these and put up some hard proof that they are different or are the same thing.

[phattyduck]

Ok, to start of... I AM an engineer (electrical engineer with an audio focus), and I have wired my own 3rd gen engine swap (correctly on the FIRST TRY) along with doing all my own mechnical work (minus welding).

Everyone needs to go back and read what the J&S engineer said... Its not the motors so much as the sensor that resonates. A knock event is an impluse and contains all frequencies. The difference between a 5.7k and 6.3k sensor means that it outputs a resonant sine wave at those frequencies. Inside the ECU, there is a filter that changes that sine wave to a voltage level that the ECU can easily interpret. Whether the sensor resonates at 5.7k or 6.3k or whatever shouldn't matter much as long as the filter is setup correctly.

My *opinion* is that the GM sensor is at least 90% as good as the stock Toyota sensor. In a modified motor, I would say this is a good mod as there is a larger chance of a big knock event that could blow a knock sensor but not the motor. There is no reason you should have to keep buying $100+ sensors when something less expensive does a good job. On a stock motor, I'm a big fan of "if it ain't broke, don't fix it." I'm keeping everything stock on my swap but intake, exhaust and boost control...

-Charlie

[Consynx]

^ i'm with him ^
EE aint my thing, but eng in general is awesome

basically, i wanna know what this "conversion kit" is to use the GM. what it is and how it did it basically.

[presure2]

^ i'm with him ^
EE aint my thing, but eng in general is awesome

basically, i wanna know what this "conversion kit" is to use the GM. what it is and how it did it basically.

its just a adapter for the threads, cause the GM knock sensor wont thread into the 3s block, and a pig tail, to wire it up into the 3s harness.

[Dr_Tweak]

Ok, to start of... I AM an engineer (electrical engineer with an audio focus), and I have wired my own 3rd gen engine swap (correctly on the FIRST TRY) along with doing all my own mechnical work (minus welding).

Everyone needs to go back and read what the J&S engineer said... Its not the motors so much as the sensor that resonates. A knock event is an impluse and contains all frequencies. The difference between a 5.7k and 6.3k sensor means that it outputs a resonant sine wave at those frequencies. Inside the ECU, there is a filter that changes that sine wave to a voltage level that the ECU can easily interpret. Whether the sensor resonates at 5.7k or 6.3k or whatever shouldn't matter much as long as the filter is setup correctly.

My *opinion* is that the GM sensor is at least 90% as good as the stock Toyota sensor. In a modified motor, I would say this is a good mod as there is a larger chance of a big knock event that could blow a knock sensor but not the motor. There is no reason you should have to keep buying $100+ sensors when something less expensive does a good job. On a stock motor, I'm a big fan of "if it ain't broke, don't fix it." I'm keeping everything stock on my swap but intake, exhaust and boost control...

-Charlie

Great explaination

[lagos]

Whether the sensor resonates at 5.7k or 6.3k or whatever shouldn't matter much as long as the filter is setup correctly.

belive it or not, i have done audio engineering for a living . i dont think there is a narrow band filter inside the ecu that is filtering on a software level. i think its all done on a hardware level by using a narrow band microphone (knock sensor). as you know, anything thats narrow band, means that it is tuned to that one frequency and setup to cancel everything else out. if it was all done in the ecu, then you would just use a 20-20hkz wide band sensor.

but, even if there is some type of software filtering going on, youll alwasy get better performance out of a microphine (kock sensor) that peaks at 5.7k then one that peaks at 6.3k on a spectrum analizer (if 5.7k is the frequency your trying to listen for) .


edit: we can do this all day long.... having said that, this ended up turning into a cool tech thread

This post has been edited by lagos: Jul 12, 2006 - 7:42 PM

[lagos]

and finally ....FOR THE WIN....

a copy of the toytoa bible (better then the bgb) from auto shop 101. that proves that each knock sensor is tuned to a specific frequency and that the ecu dosnt do any from of audio filtering to get its knock info from.

http://www.autoshop101.com/forms/h38.pdf

[WannabeGT4]

Nice find. I had forgotten about those.