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.

[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

[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.

[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