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Is there a knock sensor that can be used on our cars other than factory ones


questtuner82
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DSMs use the same sensor with a different plug. If the OEM SQ sensor isn't available then try getting the DSM one.

 

 

You can't just plug another manufacturers sensor into a SQ. The voltages are different. A knock sensor is just a peizo element that produces a voltage based on the amount of vibration it's exposed to. The higher the vibration the higher the voltage. Knocking creates significantly higher vibration so you get more voltage.

 

ECUs are set to ignore a certain voltage threshold. Lets say normal engine operation generates 1 volt and a knock will generate 1.5-2 volts. The ECU will ignore any voltage around 1.2 volts or less. Stock SQ knock sensors generate a maximum voltage of around 0.5 volts. So if you substituted a knock sensor from a nissan SR20 motor, (very common sensor used on alot of cars and different motors) your stock SQ ECU will think it's hearing knock 100% of the time. The SR20 sensor has a max output of around 2 volts with a nominal voltage on a running G54B of around 1 volt.

 

 

I know this because I use the SR20 sensor on my MPI. The standalone allows me to set the voltage threshold. The SR20 sensor is needed because the stock SQ sensor doesn't put out enough voltage for my standalone to detect.

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Just search for nissan SR20 knock sensor. That sensor came on MANY cars not just nissans. No balance shafts. As far as false knock,.... you have to set the voltage threshold in your ECU. Datalog a full boost run and that will give you the nominal backgound voltage.

 

 

 

 

 

 

The stock sensor has a m10x1.25 connection. The nissan sensor can only accept up to a m8 bolt.

 

http://i463.photobucket.com/albums/qq352/ucw458/Knock%20Sensor/DSC03918.jpg

 

 

I didn't want to remove a bunch of stuff then put a bolt in the stock location, cut it off and grind it smooth then tap for m8. That would be too much work. So I modified an broken stocksensor to make an adapter.

 

http://i463.photobucket.com/albums/qq352/ucw458/Knock%20Sensor/DSC03919.jpg

 

 

After cleaning it out I melted some aluminum and casted it inside the sensor body.

 

http://i463.photobucket.com/albums/qq352/ucw458/Knock%20Sensor/DSC03920.jpg

http://i463.photobucket.com/albums/qq352/ucw458/Knock%20Sensor/DSC03921.jpg

 

 

After casting I drilled and tapped the stock housing for a m6 bolt. Then belt sanded the mating surface flat.

 

http://i463.photobucket.com/albums/qq352/ucw458/Knock%20Sensor/DSC03922.jpg

http://i463.photobucket.com/albums/qq352/ucw458/Knock%20Sensor/DSC03923.jpg

 

 

This is what I ended up with. A perfect adapter.

 

http://i463.photobucket.com/albums/qq352/ucw458/Knock%20Sensor/DSC03926.jpg

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To clarify for home audience, ^ I'm looking SR20 (cheap, needs mod to fit) because I'm MPI with a higher mod build needing a different range of knock voltage. Other talk is about the stock setup & OEM sensor (pricey). Thanks. Edited by mstieg
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Ok so i got a 90 dsm knock sensor fits good. Got the plug and spliced solder the connection base timing is good and set at 10 btdc running 93 and car still has a spark knock. 18 psi stock motor stock turbo. Maft 3" mas 2.5" exhaust 2.25" hardpipes new and bigger b&p intercooler. RR FPR 41psi at idle. Just a narrowband right now. Pulls hard but wot it has a spark knock (predet) what has to be done bc ive ran my 383 stroker for my dirt track car on 87 a whole season with no issues and the 383 dynoed at 546hp with 87
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Ok so i got a 90 dsm knock sensor fits good. Got the plug and spliced solder the connection base timing is good and set at 10 btdc running 93 and car still has a spark knock. 18 psi stock motor stock turbo. Maft 3" mas 2.5" exhaust 2.25" hardpipes new and bigger b&p intercooler. RR FPR 41psi at idle. Just a narrowband right now. Pulls hard but wot it has a spark knock (predet) what has to be done bc ive ran my 383 stroker for my dirt track car on 87 a whole season with no issues and the 383 dynoed at 546hp with 87

 

First off a 383 is not a G54BT so whatever you did on that motor does not apply to a 2.6.

 

The stock 12a is inefficient above about 10 psi. It will make more boost but it makes alot more heat doing it. Not only that but the stock hotside is a little small for those boost levels. What you need is a 16g with a TD06 wheel in the hotside. A turbo shop can put that stuff inside a stock turbo housing. You also need to port the manifold and turbo hotside. That will help your setup put out more power.

 

If you care about your car you will stop boosting it to 18 psi until you get a wideband. Your setup may be leaning out and causing the knock. Your narrowband is junk and wont tell you squat about a lean condition. You could be pushing 12-13:1 which is motor blowing territory. Only a wideband will tell you that.

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