according to my limited books i have on the subaru wiring /ecu

 

it seems that the actual knock detection is done outside of the factory ecu ? and then piped into the ecu for timing control sorta like a after thought during the design process

 

so where is the small box that listens for the signal from the knock sensor located at?

 

anyone know where or what it looks like or if it even exsists?

I believe that the '86 and older EA82T uses an add on system like you describe, I think the control box is somewhere on the passenger side of the engine bay. I can go look at my parts car come day light. The '87+ Ea82T has the control built into the ECU.

 

Gary

Thats right, if its '86 or older it has a knock control unit in the left (in a rhd anyway, probably same side as your coil is on?) guard. You have to take the guard off!

However, it does not interface with the ecu, it simply changes the voltage applied to the extra two terminals on the pickup in the distributor.

As far as I can tell the knock control unit is located behind the glove box.

As far as I can tell the knock control unit is located behind the glove box.

 

 

What makes you think that? I'd have thought the RX would have it in the same place as the wagon, but maybe i'm wrong.

On the 83/84 is this the box in the fender well on the Left side of the car?

On the 83/84 is this the box in the fender well on the Left side of the car?

 

Yep.

ea81 and 85-86 turbos it will be under the fender. it connects entirely to the distributor

When I looked in my 86 FSM there is a connector for the knock control and it looks like it is behind the glove box plus when I was traceing wires trying to find a short I found a black box in there bolted behind the glove box more to the right (looking at the glove box). If it is in fact located inside the fender " i guess you learn something new everyday. Could you tell me what is this gaurd that you speak of, curious?

. Could you tell me what is this gaurd that you speak of, curious?

 

 

Sorry, "guard" translates to "fender".

want to try and use it as a knock interface for my megasquirt and edis setup hehe

 

hmm i thought i recalled seeing a wire in the diagram running to the ecu maybe its just a signal wire to tell the ecu its knocking and to trip a check engine light if it knocks for to long

Forgive the shameless hijack, but if I understand this thread right, I can take the knock sensor off of my 86 EA82t parts car and put it on my carbureted EA82 that's getting the turbo, and then I don't need to worry about recurving the distributor?

hijack away lol

 

and umm you will need to drill and tap the hole in the block for the knock sensor

and also swap the distributor over i would bet

 

if whats been said is how it works and it infact does control the timing directly instead of the ecu doing it on the older turbo's

personaly if i was going to the trouble of boosting a non boosted motor

i would covert over to at least some kind of injection system either stock or in my case not so stock