GM knock sensor thread Options

[lagos]

is that an ATS TB inlet? looks nice. i ordered one last week!

Yup, I ordered that and the GM Knock Sensor Conversion for Doc to install. Along with the healthy dose of goodies that he's putting in the car.......should be really niiiiiiice.

i woudlnt recomend using the GM knock sensor. it dosnt work correctly for our cars and ats should stop selling it imho. keep the stock sensor.

[Fastbird]

Fastbird, I have a question for you. Sent you PM regarding the old motor.

PM Replied to.

is that an ATS TB inlet? looks nice. i ordered one last week!

Yup, I ordered that and the GM Knock Sensor Conversion for Doc to install. Along with the healthy dose of goodies that he's putting in the car.......should be really niiiiiiice.

i woudlnt recomend using the GM knock sensor. it dosnt work correctly for our cars and ats should stop selling it imho. keep the stock sensor.

What exactly doesn't work with it?? Have you actually tried one and had issues??

[jgreening]

knock sensors work because they blow when detonation occurs rather than grenading your engine. The reason people switch to the GM sensor is because it is "stout" and doesn't blow as often as the Toyota one. Just what I want in a knock sensor

[Fastbird]

knock sensors work because they blow when detonation occurs rather than grenading your engine. The reason people switch to the GM sensor is because it is "stout" and doesn't blow as often as the Toyota one. Just what I want in a knock sensor

That makes no sense at all. The purpose of the knock sensor is not to defeat detonation by "blowing" as you seem to think. What the knock sensor does is detect knocking in the motor, relay what it's seeing to the computer, which in turn retards timing to get the motor to stop knocking.

The problem with the Toyota knock sensors is that they're not very hardy. One good bout of knock and you've got a dead sensor. Next time you end up getting knock, with a dead sensor not detecting it, you are at MUCH increased risk of damaging your motor. I can personally attest to the GM knock sensors putting up with a TON of knock and not even batting an eye, I've seen it myself both in car and on the dyno multiple times.

For the time being, I'm convinced that the GM conversion is a smart move.

[jgreening]

For the time being, I'm convinced that the GM conversion is a smart move.

Go read about the people on mr2oc.com that have blown up their 3sgte using the GM knock sensor. As for my comment, I meant that the Toyota knock sensor will blow under serious detonation event. Is this ideal? Of course not. Is it better than grenading your engine? Of course.

The problem with the GM knock sensor from the reading I have done is that it simply misses alot of detonation. Some posts have indicated that it is "listening" for a different frequency. I have no idea if this is true or not. What I do know is that I have read about more than a couple examples of broken ringlands with engines with the GM knock sensor.

This post has been edited by jgreening: Jul 10, 2006 - 1:46 PM

[lagos]

knock sensors work because they blow when detonation occurs rather than grenading your engine. The reason people switch to the GM sensor is because it is "stout" and doesn't blow as often as the Toyota one. Just what I want in a knock sensor

That makes no sense at all. The purpose of the knock sensor is not to defeat detonation by "blowing" as you seem to think. What the knock sensor does is detect knocking in the motor, relay what it's seeing to the computer, which in turn retards timing to get the motor to stop knocking.

The problem with the Toyota knock sensors is that they're not very hardy. One good bout of knock and you've got a dead sensor. Next time you end up getting knock, with a dead sensor not detecting it, you are at MUCH increased risk of damaging your motor. I can personally attest to the GM knock sensors putting up with a TON of knock and not even batting an eye, I've seen it myself both in car and on the dyno multiple times.

For the time being, I'm convinced that the GM conversion is a smart move.

the GM sensor is tuned to a different frequency. its not going to hear a lot of the detonation that is going on and wont report detonation as well as the toyota one.

the only time the toyota ones blow, is when there was very massive detonation. if this ever happens, it will throw a cel code right away and you will know about it. youll never be driving on a blown sensor and now know it. think of it like a fuse.... its the first thing to blow, and if it does, the ecu will go into safe mode and youll be glad the knock sensor is all that broke.

ive had my factory one for 2+ years. never had any issues with it.

i know your trying to do the right thing for your motor, but this is one of those times where you should just trust the guys who have had their swaps for a while and have done a ton of research into this.

This post has been edited by lagos: Jul 10, 2006 - 1:56 PM

[Fastbird]

Ok guys, I can understand what you're saying now. The reason when first presented didn't mention anything about frequencies for the respective sensors, and the statement just seemed out in left field. Now that you've explained it a little better it makes perfect sense. Thanks for the clarification.

[jgreening]

i know your trying to do the right thing for your motor, but this is one of those times where you should just trust the guys who have had their swaps for a while and have done a ton of research into this.

I love this quote and plan to utilize it in my signature. Thanks Art.

Good luck with the car when its complete FastBird. Doc will fix you up!

[lagos]

i roxors @ teh wizdomz

[Fastbird]

Well guys, after digging around on MR2OC for a while today, I've seen some good information on the knock sensors, but not enough to warrant having Doc go in there to undo what's already been done (the KS swap). We're just going to press on with the convesion as it's already installed, and granted while I did see guys claiming they didn't work and one or two guys with issues, that can happen with ANY part, and I saw a lot of good information supporting the GM KS conversion also.

I do appreciate the information and words, but I think this may be a case of long tubes vs. mid length headers in the F-Body world. I.E. it could easily swing either way (NO ONE ABUSE THAT STATEMENT )

[lagos]

Well guys, after digging around on MR2OC for a while today, I've seen some good information on the knock sensors, but not enough to warrant having Doc go in there to undo what's already been done (the KS swap). We're just going to press on with the convesion as it's already installed, and granted while I did see guys claiming they didn't work and one or two guys with issues, that can happen with ANY part, and I saw a lot of good information supporting the GM KS conversion also.

I do appreciate the information and words, but I think this may be a case of long tubes vs. mid length headers in the F-Body world. I.E. it could easily swing either way (NO ONE ABUSE THAT STATEMENT )

its a case of sticking a bigger fuse into your fuse box, because your fuses keep blowing out. aka, not the right way to fix a problem. but hey, its your motor.

[jgreening]

Well guys, after digging around on MR2OC for a while today, I've seen some good information on the knock sensors, but not enough to warrant having Doc go in there to undo what's already been done (the KS swap). We're just going to press on with the convesion as it's already installed, and granted while I did see guys claiming they didn't work and one or two guys with issues, that can happen with ANY part, and I saw a lot of good information supporting the GM KS conversion also.

I do appreciate the information and words, but I think this may be a case of long tubes vs. mid length headers in the F-Body world. I.E. it could easily swing either way (NO ONE ABUSE THAT STATEMENT )

Fastbird, did you see this thread? If not, I would read that before proceeding. Good luck.

[Dr_Tweak]

Okay, normally I let things like this slide, but I've got to step in here. I know you're all probably just trying to help, but keep this in mind:

Number one, this thread is about Fastbird's 3SGTE swap, so let's please not fill it with endless posts about the GM knock sensor. Make another thread if you want.

Second, the GM knock sensor is NOT being used to "correct" a knock problem. If an engine is knocking, there is something WRONG with it, and replacing it with a "larger fuse" as you said would be a mistake.

THIS IS NOT WHAT'S GOING ON HERE.

Fastbird is replacing the sensor because they often show up broken and he was one step ahead. I've read that thread that was mentioned above, and many more about the sensor. While there is no lack of argument on the subject, real world testing and results that have been delivered from ATSAaron AND John at J&S (You DO know who J&S is, don't you?) show that the GM knock sensor functions just fine. It's not a cure to knock and no one is saying it is! It's just a less expensive sensor that works perfectly fine.

Lastly, this is Fastbird's engine, Fastbird's swap, he's done the research, and it's his decision to make. Thank you all for your suggestions and comments. Case closed.

This post has been edited by Dr_Tweak: Jul 14, 2006 - 7:03 AM

[lagos]

You're not a professional mechanic and you're not an engineer, so lay off.

neither are you.

[WannabeGT4]

You're not a professional mechanic and you're not an engineer, so lay off.

neither are you.

burn!




Also... knock sensors are application specific... different blocks resonate at different frequncies hence different knock sensors. Monitoring the wrong frequency is not what you want to do when trying to detect knock. PERIOD.

EDIT: Just read the link that Jay posted. It is definitive proof that you should not use a GM knock sensor. Read 510Rob, RickyB's and ATSAarons posts on the second page.

This post has been edited by WannabeGT4: Jul 11, 2006 - 6:40 PM

[brianforster]

i promised myself id stay out of this but how does atsaarons post in that thread prove you shouldnt buy that knock sensor? just curious

[Dr_Tweak]

You're not a professional mechanic and you're not an engineer, so lay off.

neither are you.

LOL, well if that's the way you feel, I'm not going to argue with you about it Don't get me wrong, and don't get pissed at me about it. I like you, and I think that you're a great asset to this forum. I'm just bringing to your attention that you sometimes come across as a jerk the way you talk down to people. I'm not the only one that's noticed it.

I make a motion for a mod to start a new thread about knock sensors and move all knock-sensor related posts out of this thread and into that one.

-Doc

This post has been edited by Dr_Tweak: Jul 11, 2006 - 8:19 PM

[jgreening]

i promised myself id stay out of this but how does atsaarons post in that thread prove you shouldnt buy that knock sensor? just curious

pure and simple, he is biased. He sells a GM sensor adapter kit. He does so because so many people have problems with knock sensors blowing. I imagine he has sold a ton of them and made pretty good money out of it. Buying the GM sensor will reduce the occurence of blowing knock sensors. However, as has been pointed out, that should not be your first concern when selecting a knock sensor.

Most times knock occurs because of too much timing, "hot spots" on cylinders or cylinder walls, too rich or too lean condition, ineffective intercooling or other problems that should be addressed to GET RID OF THE KNOCK. Buying a different sensor so you dont get timing retard (knock response) is similar to buying a less sensitive fire alarm for your house so that you aren't woken up at night when there is "just a little smoke".

[brianforster]

thanks for clearing it up jay, im going to have to say that i would definitly go OEM with a sensor like a knock sensor, but at the same time fastbird and tweak are big boys and if they choose to go that route even after reading the warnings then that is between them

[jgreening]

thanks for clearing it up jay, im going to have to say that i would definitly go OEM with a sensor like a knock sensor, but at the same time fastbird and tweak are big boys and if they choose to go that route even after reading the warnings then that is between them

I agree. But, Doc's attacks on Art were out of line, IMO. Art does more for this community in providing information and troubleshooting advice than ANYBODY! Plus I like his hair.

[presure2]

Plus I like his hair.

that in itself is worth a couple points in my book, seeing as how i have NONE.
LMAO.

[Dr_Tweak]

thanks for clearing it up jay, im going to have to say that i would definitly go OEM with a sensor like a knock sensor, but at the same time fastbird and tweak are big boys and if they choose to go that route even after reading the warnings then that is between them

I agree. But, Doc's attacks on Art were out of line, IMO. Art does more for this community in providing information and troubleshooting advice than ANYBODY! Plus I like his hair.

I'm going to have to see this hair I think

Back to the subject at hand, jgreening, you're still going back to the issue of using the GM knock sensor to "fix" a knocking engine. As I agreed, that's not the right reason to use this and would be a bad idea. The problem has to be fixed, not the symptom! But from the research I've seen and my own experience, there's no problem using a GM knock sensor as a less expensive replacement.

A good thing to think of is that if you purchase an MSD knock monitor, it comes with a GM sensor. Since this is a device that a tuner would use on a dyno to watch for detonation, and it's accurate enough for that, then wouldn't it be accurate enough for the ECU?

-Doc

This post has been edited by Dr_Tweak: Jul 14, 2006 - 7:05 AM

[WannabeGT4]

thanks for clearing it up jay, im going to have to say that i would definitly go OEM with a sensor like a knock sensor, but at the same time fastbird and tweak are big boys and if they choose to go that route even after reading the warnings then that is between them

I agree. But, Doc's attacks on Art were out of line, IMO. Art does more for this community in providing information and troubleshooting advice than ANYBODY! Plus I like his hair.

Art has been nothing but helpful to everyone. I don't know how someone could label him a jerk. Just because his responses are short and concise doesn't mean he's being a jerk... You have to take into consideration that he is one of the most active 3S swapped members on this board so he's going to get a lot of questons thrown his way. We should be thanking him for even taking time to answer all of these questions, not criticizing his internet etiquette... not to mention his help is free.

Thank you Lagos! You're an invaluable asset to this forum.

[WannabeGT4]

Back to the subject at hand, jgreening, you're still going back to the issue of using the GM knock sensor to "fix" a knocking engine. As I agreed, that's not the right reason to use this and would be a bad idea. The problem has to be fixed, not the symptom! But from the research I've seen and my own experience, there's no problem using a GM knock sensor as a less expensive replacement.

A good thing to think of is that if you purchase an MSD knock monitor, it comes with a GM sensor. Since this is a device that a tuner would use on a dyno to watch for detonation, and it's accurate enough for that, then wouldn't it be accurate enough for the ECU?

-Doc

If it can be used to "fix" a knock problem it can let that same problem exist where a stock knock sensor would alert the ECU. That's not something I want to happen. I'll stick with a sensor that is designed for the frequency that our blocks resonate at.

MSD knock monitor is just another tool. Just because it can detect knock doesn't mean it was meant for our ECU... This has already been covered in the MR2OC post that Jay linked to.

This post has been edited by WannabeGT4: Jul 11, 2006 - 10:31 PM

[lagos]

thanks for clearing it up jay, im going to have to say that i would definitly go OEM with a sensor like a knock sensor, but at the same time fastbird and tweak are big boys and if they choose to go that route even after reading the warnings then that is between them

I agree. But, Doc's attacks on Art were out of line, IMO. Art does more for this community in providing information and troubleshooting advice than ANYBODY! Plus I like his hair.

Art has been nothing but helpful to everyone. I don't know how someone could label him a jerk. Just because his responses are short and concise doesn't mean he's being a jerk... You have to take into consideration that he is one of the most active 3S swapped members on this board so he's going to get a lot of questons thrown his way. We should be thanking him for even taking time to answer all of these questions, not criticizing his internet etiquette... not to mention his help is free.

Thank you Lagos! You're an invaluable asset to this forum.

thanks man. that means a lot to me.



tweak... i just went back a read all my post in this thread. i think you should do the same thing. im sorry, but in this case, you are the one acting like an asshole. all i did was try to be helpful to fastbird. jgreening did the same thing and was trying to give the same exact advice as i did... yet you single me out? then you try to take some form of cheap shot about my wiring or how many swaps ive done vs you? wtf is that? you dont even own a celica, let alone a swaped one. why you talking cheap shots at me? greening never turns a bolt on his car, you dont put down his advice ?

you need to be a little more open minded and a little less sensative. im not a cheerleeder that cheers people on even when i see them making a mistake. im very honest and to the point. get used to it.

This post has been edited by lagos: Jul 11, 2006 - 11:15 PM

[sinner96ST]

Tweaks been an invaluable member to this site, as much as Lagos has been. You two should just shake hands, and get over it. Start an actual technical thread about the knock sensor, this one has gone to junk with the comments.

I respect & trust both of your opinions, but if you can't see eye to eye, at least explain the reasons and use factual information instead of insults & such to prove your point. We would get more out of this thread as a community, if everyone just did that instead of argue.

This post has been edited by sinner96ST: Jul 12, 2006 - 4:41 AM

[presure2]

tweak... i just went back a read all my post in this thread. i think you should do the same thing. im sorry, but in this case, you are the one acting like an asshole. all i did was try to be helpful to fastbird. jgreening did the same thing and was trying to give the same exact advice as i did... yet you single me out? then you try to take some form of cheap shot about my wiring or how many swaps ive done vs you? wtf is that? you dont even own a celica, let alone a swaped one. why you talking cheap shots at me? greening never turns a bolt on his car, you dont put down his advice ?

you need to be a little more open minded and a little less sensative. im not a cheerleeder that cheers people on even when i see them making a mistake. im very honest and to the point. get used to it.

X2
art, you know how much i appreciate your help around the forums.
tweek, your a valuble asset to this community as well, helping out the kids that cant, or dont wanna jump in and get theyre hands dirty themselfs.
lets all just sit back and have a beer, and move on.
if needed, we can just start another knock sensor thread.
i havent given my thoughts on the gm knock sensor thing, but in short, being that when you break it down, all the knock sensor is is a tuned microphone, and the 2 "microphones" we're talking about are tuned to 2 diffrent frequncys, i'd be concerned weather the GM one will pick up the frequency emmited by the cylinder walls when detonation occurs.
now, from some of the posts on mr2oc, it seems as tho the GM knock sensor DOES pick up knock, but the question is weather its picking up the proper FREQUENCY of the knock, since the 3s block basicly becomes the tuning fork.

[Fastbird]

Guys, I want to clear something up. I did NOT buy the knock sensor conversion so I wouldn't see knock. That would be a huge mistake (not to mention really uneducated buying), and I think that's where a lot of this is coming from. I bought the GM knock sensor conversion so that if I DID encounted knock suddenly and violently, I wouldn't be stuck paying $150 for a new knock sensor.

I think that a lot of the issue stemming this on is that there's most likely quite a few people who don't understand why knock happens and go buy the ATS kit thinking it's going to make the knock go away, which in itself is a HUGE mistake. You need to correct the condition that's causing the knock, not just change the sensor to make it go away (although I did that once because I had a faulty sensor in my T/A ). And like Lagos said, there's a variety of conditions that can cause knock to include hot spots in the burn, lean or rich conditions, too much timing, poor intercooler efficienty (essentially raised IAT's because as we all know as you compress something it heats up).

Something about the GM knock sensor thread from MR2OC that's buried towards the end. Didn't someone find that they actually have a +/-1K response?? In that case, shouldn't the GM sensor be just fine considering it was tested at 5700 and the Toyota one was tested at 6300?? (sorry if the numbers aren't correct, it's early and I don't feel like digging through that thread right now). Not to mention that there was a handful of guys in that thread who did datalogging and intentionally put the car into knocking conditions and got normal reactions from the GM knock sensor.

*Edit* I'd like to dicuss really quickly the knock resonance frequency seen in the blocks. I think we all agree that the bore size plays a major factor in the plan, but here's a though: What about the volume?? What I mean is that what if you're running a terrible intercooler, and you start getting pre-detonation with the cylinder in the bottom of the bore as opposed to the top of the bore?? Would that not drastically change the frequence which the knock resonates? If you take a bare block and tap a cylinder, it will be the same frequency every time. Cap that cylinder off at each end, and the frequency changes. Move one of those caps into the cylinder (stroke, or piston travel) and it changes yet again. *Disclaimer* This is just my own mind at work here, just getting a quick thought out about that.

I apologize for the big stink that's been made here by me for what seems to be the perception that I bought the kit just to not see knock. I didn't realize that's what what the interpretation seemed to be, and I hate to see tension like what's been coming out in this thread between some of the most respected members of this forum.

This post has been edited by Fastbird: Jul 12, 2006 - 7:08 AM

[brianforster]

one thing that doesnt make sense to me is you say you gave doc 7k to do this swap for everything yet you are shy about spending 150$ on an oem knock sensor?

[jgreening]

Fastbird and Doc:

Your logic escapes me here. Please explain why this statement from Justin does not concern you:

If it can be used to "fix" a knock problem it can let that same problem exist where a stock knock sensor would alert the ECU.

Thanks.

Jay

greening never turns a bolt on his car

Hey now, thats not true. I tightened a battery tie down once.

This post has been edited by jgreening: Jul 12, 2006 - 10:01 AM

[Dr_Tweak]

[quote name='jgreening' date='Jul 12, 2006 - 2:58 PM' post='455015']
Fastbird and Doc:

Your logic escapes me here. Please explain why this statement from Justin does not concern you:

[quote name='WannabeGT4' post='454874' date='Jul 11, 2006 - 10:30 PM']
If it can be used to "fix" a knock problem it can let that same problem exist where a stock knock sensor would alert the ECU. [/quote]

It can't be used to fix a knock problem. It never was intended to either.

-Doc

[CelicaSTX02]

I say, Fastbird should stick to the GM knock sensor......the worst that would happen is his engine blowing up. But hey...he'll be able to fix it because of all the money he saved by buying the GM sensor instead of the OEM one.

[jgreening]

[quote name='Dr_Tweak' date='Jul 12, 2006 - 10:08 AM' post='455016']
[quote name='jgreening' date='Jul 12, 2006 - 2:58 PM' post='455015']
Fastbird and Doc:

Your logic escapes me here. Please explain why this statement from Justin does not concern you:

[quote name='WannabeGT4' post='454874' date='Jul 11, 2006 - 10:30 PM']
If it can be used to "fix" a knock problem it can let that same problem exist where a stock knock sensor would alert the ECU. [/quote]

It can't be used to fix a knock problem. It never was intended to either.

-Doc
[/quote]

QUIT PLAYING WORD GAMES! You know the word "fix" was in quotation marks. Justin wasn't saying that the GM sensor could fix a knock problem. You know that. The question is: Why aren't you concerned (based on the information that we have all now read) that the GM knock sensor which is designed for a larger bore cylinder will not pick up some knock and possibly result in engine failure in a 3sgte?

This post has been edited by jgreening: Jul 12, 2006 - 10:17 AM

[presure2]

fastbird & tweek:
i think your misunderstanding us.
we understand your not using it to "correct" a problem.
what we are saying is that by using the GM sensor, knowing that its harder to blow...wouldnt you WANT to be safer knowing the OEM blows sooner if somthing goes wrong, putting you into safe mode?

as a side note, fastbird, i happen to have a OEM 3sgte knock sensor sitting at home, still on the block @ my moms house.
if you want it, i'd be willing to sell it to ya for a good price.

[CelicaSTX02]

fastbird & tweek:
i think your misunderstanding us.
we understand your not using it to "correct" a problem.
what we are saying is that by using the GM sensor, knowing that its harder to blow...wouldnt you WANT to be safer knowing the OEM blows sooner if somthing goes wrong, putting you into safe mode?

as a side note, fastbird, i happen to have a OEM 3sgte knock sensor sitting at home, still on the block @ my moms house.
if you want it, i'd be willing to sell it to ya for a good price.

lol, you should make this offer to everybody, how much are you selling it for?

This post has been edited by CelicaSTX02: Jul 12, 2006 - 10:33 AM

[Fastbird]

I say, Fastbird should stick to the GM knock sensor......the worst that would happen is his engine blowing up. But hey...he'll be able to fix it because of all the money he saved by buying the GM sensor instead of the OEM one.

This is an absolutely useless post. How about something constructive next time.

Yeah, I did drop $7K into the swap. And yes, I am concerned about having to possibly pay $150 for a part. What's the problem with that?? Just because I drop the dough doesn't mean I'm not conscientious about how my money is spent. Frankly, I find that a lot of Toyota's parts are overpriced. $150 for a knock sensor?? $400 for a freaking oxygen sensor (buddies 02 Tacoma)?!?!?!? When there's people running a GM sensor without issue (just because some people have issues doesn't mean all will) when it costs $25 and then those that insist on paying $150 for a OEM one, who's the stupid one there?

Yes, I am using the GM knock sensor because I know that it's harder to blow. Think about this: You're running the car hard without a datalogger. You start to get knock that you can't hear audibally, and it's working as advertised. Then the OEM one blows and before you have a chance to react (you're still in the gas) the knock continues and you pop a piston. I'd rather have the GM knock sensor in there with it's ability to take a bit more abuse than the OEM one.

This is turning into a pissing match more than anything. Obviously the OEM sensor works, and the GM sensor is proven to work also. Some like it, some don't. Leave it at that, and let those who choose to use the GM sensor use it without the condascending statements like "It's your motor" or what CelicaSTX02 said.

[presure2]

[quote]QUOTE(CelicaSTX02 @ Jul 12, 2006 - 11:08 AM)

I say, Fastbird should stick to the GM knock sensor......the worst that would happen is his engine blowing up. But hey...he'll be able to fix it because of all the money he saved by buying the GM sensor instead of the OEM one.
This is an absolutely useless post. How about something constructive next time.[/qoute]

X2
next comment like that will get you a nice vacation from the site, jacka$$.
[quote]Then the OEM one blows and before you have a chance to react (you're still in the gas) the knock continues and you pop a piston. I'd rather have the GM knock sensor in there with it's ability to take a bit more abuse than the OEM one.[/quote]
thats not how the ecu works tho...it detects knock, and pulls timing accordingly, if your in the gas hard, and it knocks hard enough to blow the knock sensor, the ECU drops you back into safe mode, using the preset "safe mode" map.

[WannabeGT4]

Fastbird and Doc:

Your logic escapes me here. Please explain why this statement from Justin does not concern you:

If it can be used to "fix" a knock problem it can let that same problem exist where a stock knock sensor would alert the ECU.

It can't be used to fix a knock problem. It never was intended to either.

-Doc

QUIT PLAYING WORD GAMES! You know the word "fix" was in quotation marks. Justin wasn't saying that the GM sensor could fix a knock problem. You know that. The question is: Why aren't you concerned (based on the information that we have all now read) that the GM knock sensor which is designed for a larger bore cylinder will not pick up some knock and possibly result in engine failure in a 3sgte?

LOL! Maybe I should have italicized the word "fix" as well. Thanks for clearing that up Jay.

Yes, I am using the GM knock sensor because I know that it's harder to blow. Think about this: You're running the car hard without a datalogger. You start to get knock that you can't hear audibally, and it's working as advertised. Then the OEM one blows and before you have a chance to react (you're still in the gas) the knock continues and you pop a piston. I'd rather have the GM knock sensor in there with it's ability to take a bit more abuse than the OEM one.

This is turning into a pissing match more than anything. Obviously the OEM sensor works, and the GM sensor is proven to work also. Some like it, some don't. Leave it at that, and let those who choose to use the GM sensor use it without the condascending statements like "It's your motor" or what CelicaSTX02 said.

Ever consider the fact that the GM sensor doesn't blow because it's not designed to "hear" the same frequency the Toyota sensor is.
You know that the knock sensor blowing puts the car into low boost mode right? Blowing the sensor will not alow you to continue knocking. It is a safety feature built into the Toyota ECU. If you have knock severe enough to blow your sensor there is obviously something wrong and it puts the car into low boost mode. That is, if you still have your T-VSV connected. If not you should at least have it wired to a light so you know when it's being activated by the ECU. Again, all of this is covered in the post that Jay linked to at MR2OC.

[Dr_Tweak]

I say, Fastbird should stick to the GM knock sensor......the worst that would happen is his engine blowing up. But hey...he'll be able to fix it because of all the money he saved by buying the GM sensor instead of the OEM one.

This is an absolutely useless post. How about something constructive next time.

Yeah, I did drop $7K into the swap. And yes, I am concerned about having to possibly pay $150 for a part. What's the problem with that?? Just because I drop the dough doesn't mean I'm not conscientious about how my money is spent. Frankly, I find that a lot of Toyota's parts are overpriced. $150 for a knock sensor?? $400 for a freaking oxygen sensor (buddies 02 Tacoma)?!?!?!? When there's people running a GM sensor without issue (just because some people have issues doesn't mean all will) when it costs $25 and then those that insist on paying $150 for a OEM one, who's the stupid one there?

Yes, I am using the GM knock sensor because I know that it's harder to blow. Think about this: You're running the car hard without a datalogger. You start to get knock that you can't hear audibally, and it's working as advertised. Then the OEM one blows and before you have a chance to react (you're still in the gas) the knock continues and you pop a piston. I'd rather have the GM knock sensor in there with it's ability to take a bit more abuse than the OEM one.

This is turning into a pissing match more than anything. Obviously the OEM sensor works, and the GM sensor is proven to work also. Some like it, some don't. Leave it at that, and let those who choose to use the GM sensor use it without the condascending statements like "It's your motor" or what CelicaSTX02 said.

'nuff said.

-Doc

[presure2]

'nuff said.

-Doc

not at all, its clear he really dont understand how the knock sensor system works.

[lagos]

shouldn't the GM sensor be just fine considering it was tested at 5700 and the Toyota one was tested at 6300??

what part of narrow band sensor dont you understand? narrow band means that its only tuned to pick up that one specific frequency. this is done so that the sensor will only pick up knock at the correct frequency and ignore any false alarms. if you agree that the sensors are not the same frequency, then you should know why its bad to use one.

I bought the GM knock sensor conversion so that if I DID encounted knock suddenly and violently, I wouldn't be stuck paying $150 for a new knock sensor.

if you encounter massive knock .... it dosnt mean your sensor will blow. i got severe detonation on the dyno (with a dyno chart to prove it) and my knock sensor did its job and still works great since 1990.

the ats kit costs about 80$ . a new OEM sensor from toyota sells for 124.27$. seeing as how its a vital part of the motor, this is not where i would cut my budget and try to save 40bucks

Yes, I am using the GM knock sensor because I know that it's harder to blow. Think about this: You're running the car hard without a datalogger. You start to get knock that you can't hear audibally, and it's working as advertised. Then the OEM one blows and before you have a chance to react (you're still in the gas) the knock continues and you pop a piston. I'd rather have the GM knock sensor in there with it's ability to take a bit more abuse than the OEM one.

you clearly dont know how the whole knock system works. if the GM sensor can take more abuse, then it means that there is more abuse happening inside of you motor that the sensor is not picking up. youll blow a piston before you blow the sensor if you use the GM one. if the knock sensor ever blows (they very rarely blow on a stock 3s) the ecu will know it right away and save the motor.


====================================================================

now lets get down the the real issue here. drtweak talked you into all these upgrades and now is trying to fight tooth and nail so that he dosnt look like he made a bad call on something. thats all this is about. i mean, you have a million people on here trying to tell you how bad that sensor is, and only one person whos trying to play word games to try to justify keeping it. i dont know how you can ignore the advice of people who have daily driven, dynoed, tracked, and raced their swaped cars for years.

[Fastbird]

First things first, Dr. Tweak did NOT talk me into all these mods. Specifically speaking, the knock sensor conversion was MY idea. So please leave the assumption that he's fighting over this to cover his own rear out because that is completely wrong.

Blowing the sensor will not alow you to continue knocking. It is a safety feature built into the Toyota ECU. If you have knock severe enough to blow your sensor there is obviously something wrong and it puts the car into low boost mode. That is, if you still have your T-VSV connected. If not you should at least have it wired to a light so you know when it's being activated by the ECU. Again, all of this is covered in the post that Jay linked to at MR2OC.

Ok, THAT I did not know. I was not aware that Toyota had a safety feature built into the ECM to protect the car with loss of the knock sensor. Lagos though, to say that I completely do not understand knock systems is a bit pre-emptive. I may not know everything, but I think it's pretty clear that I have a certain understanding of what they're for and what they do and how they interact with the ECM.

Have a look at what John @ J&S had to say in a post in the talked about thread on 2 Sept 2004 since everyone is so up tight about that one post which is pushing almost over 2 years old at this point.

You guys are making way too big a deal out of this.

A few years ago, a GM knock sensor guy sent me a list of the most commonly used sensors. At the time, they were only making them in three frequencies to cover all their engines. The frequencies were 5.2 kHz, 6.0 kHz, and 7.0 kHz.

They call their sensors "broadband resonant", and they will respond over a kHz or so bandwidth.

GM chose broadband sensors for a number of reasons. The knock frequency can increase a few hundred Hz with an increase in combustion temperatue, so the bandwidth of the sensor must be wide enough to allow for that. Also, broadband sensors will cover for normal manufacturing tolerances of the engine, and, because they will work on more engines, they don't need to stock as many part numbers.

Right there is what I was talking about. They respond over a variety of frequencies, not just a single pre-programmed frequency.

I just had a look around MR2 OC and other than that one thread and a couple of people saying don't use it, there's several more over there that are promoting it and having no issues.

I noticed that no one had anything to say about my comments about the changing frequencies at which knock will register based on the position of the piston in the cylinder???

This post has been edited by Fastbird: Jul 12, 2006 - 12:55 PM

[Consynx]

don't almost all sensors go into a safe mode when the sensor doesn't reply back to the ecu without a voltage reading?

cars have come a LONG way.

also, gotta use that frequency completely
it covers a RANGE, but the range depends on the type of sensors and such.

and since engine resonancies can chance easily, i'd just stick with what there is.

or if you got money, just find a way to bypass the knock sensor completely and run 103 octane all the time

This post has been edited by Consynx: Jul 12, 2006 - 12:38 PM

[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.

Look at this. Where does the knock sensor install?? I don't know for sure about the 3S-GTE, but on ALL GM motors the knock sensor installs into a water jacket. WHY?? Because the knock sensor pickup will be always submerged in the coolant which makes an excellent transmitter for various knocks that occur within the motor. Hence, I don't see HOW the knock sensor can only pick up on a single tuned frequency. Support for this again is shown in the above paragraph.

You guys are starting to beat a dead horse with this. You're not going to change my or Doc's opinion on this. It's my motor, I'll do what I want. I took your advice with due regard, and made what I feel is an educated decision based on what I've seen from testing and real world use. Fact of the matter is that I'm sticking with the GM knock sensor because I feel that it's an adequate alternative to the overly priced OEM Toyota knock sensors, and that decision isn't going to be swayed. I know that you guys are watching out for me with what you feel is the best thing, and I sincerely appreciate that.

That said, if my motor ever grenades due to the gm knock sensor not doing it's job, I'll sponsor a meet or something (food, beverage, coordination, ect) and publicly admit I was wrong.

[jgreening]

That is one post in the thread. And if I were willing to ignor Ricky B and the testing by 510Rob, it might be enough for me to say maybe getting a knock sensor for a different frequency would be a suitable alternative.

As for your question, if stroke does not matter to knock frequency, piston position should not matter either. Even if it did, knock is pre-ignition due to the charge occuring due to compression. I would assume (I dont know this for sure) but that the piston position of detonation is within a relatively small range since that compression will occur as the piston travels toward TDC.

I know both you and Manny may have been offended by the statements "its your motor" and "see how much you save if you have to replace a blown motor" but I was not. These statements are designed to make you think if you are being penny wise and dollar foolish.

One thing to remember, we all made mistakes in our build. Why? Because during the process of the build (and afterward), we learned things that would cause us to do it differently if we did it again. I actually started a thread awhile back about things I would do differently if I were swapping today rather than two years ago for people who are in your exact position. Bottom line: its not a bad thing to have your plans critiqued by others who have been there and then change courses. We cannot possibly know all of this stuff before going through it. I wish you the best of luck.

[Fastbird]

don't almost all sensors go into a safe mode when the sensor doesn't reply back to the ecu without a voltage reading?

I would think so. I know my T/A ran like crapola when my knock sensor popped on me. But I wasn't aware that toyota had built in a way to limit boost output at the same time. Neat trick there.

[presure2]

Look at this. Where does the knock sensor install?? I don't know for sure about the 3S-GTE,

that would be on the back of the block, behind cylinder #1
knock sensor replacement, even with the engine installed, should take no more than 5 minutes with a decent jack.

[Fastbird]

That is one post in the thread. And if I were willing to ignor Ricky B and the testing by 510Rob, it might be enough for me to say maybe getting a knock sensor for a different frequency would be a suitable alternative.

As for your question, if stroke does not matter to knock frequency, piston position should not matter either. Even if it did, knock is pre-ignition due to the charge occuring due to compression. I would assume (I dont know this for sure) but that the piston position of detonation is within a relatively small range since that compression will occur as the piston travels toward TDC.

I know both you and Manny may have been offended by the statements "its your motor" and "see how much you save if you have to replace a blown motor" but I was not. These statements are designed to make you think if you are being penny wise and dollar foolish.

One thing to remember, we all made mistakes in our build. Why? Because during the process of the build (and afterward), we learned things that would cause us to do it differently if we did it again. I actually started a thread awhile back about things I would do differently if I were swapping today rather than two years ago for people who are in your exact position. Bottom line: its not a bad thing to have your plans critiqued by others who have been there and then change courses. We cannot possibly know all of this stuff before going through it. I wish you the best of luck.

Good words man. I'll clear up that I wasn't offended by the statements, just getting sick of them.

As for piston position in the cylinder, taking an LT1 as example, that's a stock 3.48" stroke. That's 3.48" where the piston could be located anywhere in that cylinder. If you're talking about a 4.00 bore, then you're looking at a volume change of approximately 43.75 cubic inches or .7125L on that cylinder between TDC and BDC. If there is a condition that's severe enough, you could possibly even detonate prior to the intake valve closing before the compression stroke has even begun (ever see a V8 with a couple of swapped plug wires). Given that, I feel that there's going to be a marked frequency change in the knock between the two points (TDC and BDC) with the volume change. I know it's not a 3S-GTE but the same theories still apply as a motor is a motor for the most part.

[jgreening]

You guys are starting to beat a dead horse with this. You're not going to change my or Doc's opinion on this. It's my motor, I'll do what I want. I took your advice with due regard, and made what I feel is an educated decision based on what I've seen from testing and real world use. Fact of the matter is that I'm sticking with the GM knock sensor because I feel that it's an adequate alternative to the overly priced OEM Toyota knock sensors, and that decision isn't going to be swayed. I know that you guys are watching out for me with what you feel is the best thing, and I sincerely appreciate that.

Please understand that some of our persistence is to make sure that misinformation is not perpetuated. I am now confident that someone finding this thread in the future can make an educated decision based on the information contained here.

[Fastbird]

Look at this. Where does the knock sensor install?? I don't know for sure about the 3S-GTE,

that would be on the back of the block, behind cylinder #1

Is that into a water jacket?? I.E. does coolant come out when removed?? I seriously don't know on the GTE but would like to.

[Dr_Tweak]

You know what you guys should do, if you really want to pursue this? Start a poll, where people put if they have the stock sensor or the GM sensor, and of those that have the GM sensor, how many have blown their engines.

If I saw a good number of people have actually blown their engines because of using the GM knock sensor, then I would change my mind on this subject.

-Doc

[Fastbird]

Please understand that some of our persistence is to make sure that misinformation is not perpetuated. I am now confident that someone finding this thread in the future can make an educated decision based on the information contained here.

That's what these forums are for, right?? I'll pony up and be the classic example once in a while.

[Dr_Tweak]

Look at this. Where does the knock sensor install?? I don't know for sure about the 3S-GTE,

that would be on the back of the block, behind cylinder #1

Is that into a water jacket?? I.E. does coolant come out when removed?? I seriously don't know on the GTE but would like to.

Nope.

[Consynx]

that was smart of GM to put it in the coolant actually...sound travels faster that way
just don't know if any kind of flow pattern of the water would actually dampen the noise :\

[CilverSeliST205]

When there's people running a GM sensor without issue (just because some people have issues doesn't mean all will) when it costs $25 and then those that insist on paying $150 for a OEM one, who's the stupid one there?

Then the OEM one blows and before you have a chance to react (you're still in the gas) the knock continues and you pop a piston. I'd rather have the GM knock sensor in there with it's ability to take a bit more abuse than the OEM one.

To Art, Manny, Jay:
Because GM sensor is harder to blow does not mean that it doesnt pick up all the knock thats occuring, it might be more sturdy thats all. It is not proof that it will ignore/not respond to certain knock frequency.

To Fastbird and Tweak:
I think that blowing a toyota KS prevents critical motor failure more so than retarding timing by unblown GM KS. By settling for a lower safety level you endanger your engine more. It is not at all good way to save money.

If you dont want toyota sensor because its too expensive to replace, dont settle for GM because it works (how well it works is still unknown)... Get J&S or MSD knock monitor.

[Fastbird]

Look at this. Where does the knock sensor install?? I don't know for sure about the 3S-GTE,

that would be on the back of the block, behind cylinder #1

Is that into a water jacket?? I.E. does coolant come out when removed?? I seriously don't know on the GTE but would like to.

Nope.

Huh......interesting. Learn something new every day.

If you dont want toyota sensor because its too expensive to replace, dont settle for GM because it works (how well it works is still unknown)... Get J&S or MSD knock monitor.

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

[Consynx]

Good words man. I'll clear up that I wasn't offended by the statements, just getting sick of them.

As for piston position in the cylinder, taking an LT1 as example, that's a stock 3.48" stroke. That's 3.48" where the piston could be located anywhere in that cylinder. If you're talking about a 4.00 bore, then you're looking at a volume change of approximately 43.75 cubic inches or .7125L on that cylinder between TDC and BDC. If there is a condition that's severe enough, you could possibly even detonate prior to the intake valve closing before the compression stroke has even begun (ever see a V8 with a couple of swapped plug wires). Given that, I feel that there's going to be a marked frequency change in the knock between the two points (TDC and BDC) with the volume change. I know it's not a 3S-GTE but the same theories still apply as a motor is a motor for the most part.

?
not quite sure what you're going for here, but i think you were just agreeing which is kewl.


also, J&S sells some kit which uses a wideband sensor and is very accurate, like $400?
it seems like it's just a piggyback sensor(semi-standalone? lol)

also, bringing a V8 in was prob a bad idea, since sensors are kept within families. although each engine is slightly different, going from a I4 to I6 would be bad. I don't think you were trying to compare the 8 to the 4 though...i just can't deal with reading all this stuff more than twice.

This post has been edited by Consynx: Jul 12, 2006 - 1:10 PM

[Fastbird]

Consynx, cliff notes was that I used how the cylinder volume changes with the stroke of the piston to represent how easily the frequency of the knock could change also.

I wasn't comparing the V8 directly to the I4, just pointed that an engine is an engine. I just used the V8 as an example because I know the bore and stroke and cylinder displacement right off the top of my head.

This post has been edited by Fastbird: Jul 12, 2006 - 1:13 PM

[lagos]

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.

[CilverSeliST205]

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.

[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.

[brianforster]

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

[Batman722]

after skimming through this post I have some newbie type thoughts....

the stock (toyota sensor) might tend to blow at times...so you want to put a different frequency sensor in so it blows less ? correct ?

isn't that the same idea as " I keep blowing a 15A fuse in the fuse box, so I will put a 25A one is so it doesn't blow anymore "

if the stock sensor blows, there is a reason why. Solve the problem - don't band-aid it until it is a bigger problem.

my .02

[jgreening]

My *opinion* is that the GM sensor is at least 90% as good as the stock Toyota sensor.

Although I am not sure how you quantified this, I generally agree. You have to ask yourself though, is the $40 extra worth the 10% (or whatever) chance that the GM sensor will not appropriately respond to catostraphic detonation?

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.

On the other hand, I have to part company with you on this one. To me, the increase chance of detonation on a modified motor increases the need for accurate knock detection. With modified (high horsepower) motors, the last thing you should be worried about is the $40 difference in the cost of these sensors.

[CelicaGT04]

after skimming through this post I have some newbie type thoughts....

the stock (toyota sensor) might tend to blow at times...so you want to put a different frequency sensor in so it blows less ? correct ?

isn't that the same idea as " I keep blowing a 15A fuse in the fuse box, so I will put a 25A one is so it doesn't blow anymore "

if the stock sensor blows, there is a reason why. Solve the problem - don't band-aid it until it is a bigger problem.

my .02

Makes sense to me batman!

ANYWAY... I read about 2 pages of this topic and figured i would just say that we all love celicas here! Why cant we all just be happy for fastbird, i mean im happy for you!! If he gets knock then he will learn! You gave your opinion and he gave his. I think we should all be happy for him, if it works, it works. If not well then i guess then you can say "I told you so!" !!! If it works then fastbird can say "I told you soo!!!" Either way im still happy for you!


Everyone on this site is a great member! Im glad we have great moderators like lagos and pressur2. I am also glad we have great people like doc to help those who dont want to get their hands dirty or want their swap done correctly. I think everyone plays a role and im playing mine! Lets just get along.

Doc great work on the swap

Fastbird- that is a nice car and i hope your happy with it! i mean hell, im happy to see it look like that!

Mario!

[lagos]

Im glad we have great moderators like lagos and pressur2.

im a moderator? woot!!!


keep reading the rest of the pages. it started out as lagos bash, but now is a cool tech talk thread.

This post has been edited by lagos: Jul 12, 2006 - 11:45 PM

[scothaniel]

the stock (toyota sensor) might tend to blow at times...so you want to put a different frequency sensor in so it blows less ? correct ?

No, thats not what ( some / few / many ) people are saying. When excessive knock happens, how long will the sensor last? All motors get knock, even when everything is running perfectly. Only in this case, the knock is like 4 counts / second (microphones pick up background sounds). When you get 50+ knocks / sec - something is wrong.

The stock sensor is known to be more fragile then most and fail after a few cases of excessive knock. The real question here is whether the GM knock sensor is listening for the correct frquency. Knock sensors listen for specific frequencies to determine knock - otherwise valve or injector tick would through off the system. Does the GM sensor listen for the same frequencies as the stock sensor?

From my experience, I believe so.

[phattyduck]

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.

On the other hand, I have to part company with you on this one. To me, the increase chance of detonation on a modified motor increases the need for accurate knock detection. With modified (high horsepower) motors, the last thing you should be worried about is the $40 difference in the cost of these sensors.

That's not quite what I wrote. I mean: A modified (ie stronger) motor can take knock events with less damage, and are often more likely to see those events (higher boost, racing, etc.). Both of these things point to the need for a hardier knock sensor, and *if* it is less sensitive it won't hurt things as much.

Its ok if you disagree though.

-Charlie

[phattyduck]

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

Very good link. I probably have that downloaded in the tech director on my other computer... I just haven't read it yet!

So, here's my *opinion* on what's going on in the knock system: Knock sensor sees knock even and resonates at a larger amplitude (shown in the graph on the second page). This signal is sent to the ECU where there is an envelope filter that is able to grab the peaks of the knock events. When this peak reaches a certain value, the knock response of the ECU is generated. In this way, the ECU can have a simple comparator watching the knock system - cheap and effective. (at one time, started investigating designing something like a J&S with a friend of mine...). There is no need for complicated electronics or computation in the ECU.

The resonant effects of the motor (peaking at the same or similar frequency as the sensor) will enhance the sensitivity of the sensor to knock events. BUT... the bandwidth of the resonance of something as complicated as a motor (with a shape NOTHING like a tuning fork and made up of many materials) should be fairly wide - and thus a sensor that is less than 1kHz away in peak frequency should still work well.

Once again, my opinion - but a fairly educated guess.

-Charlie

[jgreening]

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.

On the other hand, I have to part company with you on this one. To me, the increase chance of detonation on a modified motor increases the need for accurate knock detection. With modified (high horsepower) motors, the last thing you should be worried about is the $40 difference in the cost of these sensors.

That's not quite what I wrote. I mean: A modified (ie stronger) motor can take knock events with less damage, and are often more likely to see those events (higher boost, racing, etc.). Both of these things point to the need for a hardier knock sensor, and *if* it is less sensitive it won't hurt things as much.

Its ok if you disagree though.

-Charlie

Good point Charlie. You may be correct but I will note that almost all of the high hp 3sgte's run stock knock sensors. That surely doesn't prove anything but may be worth observing.

[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

Very good link. I probably have that downloaded in the tech director on my other computer... I just haven't read it yet!

So, here's my *opinion* on what's going on in the knock system: Knock sensor sees knock even and resonates at a larger amplitude (shown in the graph on the second page). This signal is sent to the ECU where there is an envelope filter that is able to grab the peaks of the knock events. When this peak reaches a certain value, the knock response of the ECU is generated. In this way, the ECU can have a simple comparator watching the knock system - cheap and effective. (at one time, started investigating designing something like a J&S with a friend of mine...). There is no need for complicated electronics or computation in the ECU.

The resonant effects of the motor (peaking at the same or similar frequency as the sensor) will enhance the sensitivity of the sensor to knock events. BUT... the bandwidth of the resonance of something as complicated as a motor (with a shape NOTHING like a tuning fork and made up of many materials) should be fairly wide - and thus a sensor that is less than 1kHz away in peak frequency should still work well.

Once again, my opinion - but a fairly educated guess.

-Charlie

just read that pdf. tells you exactly how it works...lol

[presure2]

lets keep this thread on topic.

[Fastbird]

lets keep this thread on topic.

[phattyduck]

just read that pdf. tells you exactly how it works...lol

I did read it. Just because that's what they tell their mechanics what is going on, doesn't mean it is 100% technically correct.

In an interesting side note: There were some Subarus built with 'overactive' knock sensors. The recommended fix from the factory: a small amount of teflon tape on the threads to insulate it from the knock vibrations... On the flip side, some of the earliest US WRXs were shipped with almost deaf knock sensors. The result? About an extra 30hp and all those great reviews of the WRX (and that 5.4 second 0-60 time) and then the motors eating themselves alive after a while.

-Charlie

[lagos]

I did read it. Just because that's what they tell their mechanics what is going on, doesn't mean it is 100% technically correct. wink.gif

all the info in there is 100% correct when it comes to toyota knock sensors and how they work. its like the bible for that kind of stuff. you can bet your 1st born child on it.

[phattyduck]

I did read it. Just because that's what they tell their mechanics what is going on, doesn't mean it is 100% technically correct. wink.gif

all the info in there is 100% correct when it comes to toyota knock sensors and how they work. its like the bible for that kind of stuff. you can bet your 1st born child on it.

That said, my long post doesn't directly contradict anything in the document...

-Charlie