I was wondering if anyone ever added a knock sensor to the SOHC ka motor? I was told to weld a sensor to my block in order to be able to use the knock feature on the safc2. Can I weld it anywhere on the block or does it have to be in a specific area. my plan was to use a dsm knock sensor . Also wondering if the knock sensor can be hook up directly on the safc 2 .I will be going turbo soon so I trying to build some sort of engine management.
I found the knock feature to be useless on the SAFCII but if you are dying to install it then Im sure it can be done somehow. Placing it is critical, put it in an improper spot and you’ll have false signals or no signal at all. Welding it to the block may not be your best bet aswell. I would weld a bung then screw the sensor in. You will get different signals if its welded and not.
The SAFCII cannot be directly wired into the knock sensor from what I know, I had to splice the ECU knock wire, not the actual wire coming from the knock sensor (in my DSM) to make it work.
Sounds like alot of hassle for a so-so feature.
I dont think thing the s13 has a knock wire to the ecu . I dont thing that will be possible then . 
If you really want to use the knock sensor … I believe the only way you can use it is by purchasing the complete emanage kit (including ignition kit)
I believe there you can wire the knock sensor directly to the emanage and have the emanage control the ignition timing (advance and/or retard).
Have Fun
I like the knock sensor readout function on the SAFC2. Although you can’t use it to tune the car with the SAFC it lets you see if your engine is running like ass on a bad tank of gas or on a hot day. I set it up to flash at me if it pings too hard and then I know to ease off.