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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.

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PM Replied to.

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

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

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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.

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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

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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

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.

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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!

i roxors @ teh wizdomz

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 )

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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.

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

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

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neither are you.

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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

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

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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

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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".

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

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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.

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

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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

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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.

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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

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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

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

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.

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

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?

Fastbird and Doc:

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

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Thanks.

Jay


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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