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]

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