First do I need it?
And second what will happen if I leave it unplugged?

I'm in the process of turboing an N/A and I don't want to drill out the spot for the sensor. The guy I'm talking with about this said that if I leave it unplugged the ecu will retard the timing as a default.

Is this true or do I have to mount the sensor?

thanks, John

 

Just put the sensor in. If it's true that if it's not in then ignition is always retarded, then you're giving up a bunch of power and torque. If it's not true, then your in dangerous territory and are risking an engine failure.

Seriously, knock sensors are very important, it's not worth leaving it out because you couldn't be bothered. Don't do it half assed.

 

Duct tape it to the side of the housing?



P.S I'd be real worried about drilling considering the NA housings dont have cast in place for it and the housing is less then 1/2 inch thick till you hit water jacket.

 

doesn't the knock sensor only work under 4500 rpm?

 

Drill out the spot for the sensor??? can you be a little more specific... S4 motors has the knock sensor in the middle steel plate and the S5 motors has one above each sparkplug. Are you saying that your motor is built with S4 aluminum housings and a S5 center plate? and therefore you have no spot to put the sensor???

 

don't worry about it. honestly do you think a knock sensor retarding timing is really going to save a rotary? BTW I *think* it is only active under ~4k rpm, basically low rpm high load situations. (towing?) Try searching though I'm sure this has been covered.

 

The S4 turbo block has the knock sensor in the center iron wear the oil fill tube goes into the block. Th S4 N/A has a blank molding in the same spot.

I'm turboing an N/A block. As far as I know N/A's don't have a knock sensor.

 

I have a question then, since the J and S knock sensor is a single sensor, and the S5 TII has 2 provisions for sensors,(above the spark plugs) where should the knock microphone/sensor be placed?

 

That's kind of wht I'm trying to figure out!

So, I need it.

Is there anywhere else on the block that I could put it and still work?

 

the FSM saids that the ecu only recieve very low voltage from the knock sensor if the engine knocks, other than that doesnt recieve any voltage at all. so if you wanna have it or not is up to you, but you dont need it at this point. plus is good to have because the ecu retard's the ignition 5 degrees more that were it is at under boost. if you decided not to use it, make sure that the wire dont get grounded or it will burn the ecu

eddie

 

If the ECU sees no voltage on that pin when the engine is running normally, how would not having it connected (and thus no voltage) somehow create a voltage for the ecu to react to? Also, doesnt the knock sensor run to a knock control box located near the ecu, and from there the voltage gets bumped up to something the ecu can read?

 

you do not need the knock sensor, i know pletny of people that went NA to TII and they never used a knock sensor, nothing ever happend to there motor.