as the thread name says, i have a power FC on my FC and when the revvs increase so does the knock guage, even from a neutral rev, any idea what may be going wrong?...

 

uh yeah, its accuracy is notoriously spotty. Some people say that if you can fix any rattling drivetrain parts or other loose things in the engine bay you can improve it. Maybe.

On some cars it's consistent (and thus knock only spikes when you are actually knocking), but on many other cars it is not reliable. I've got a friend with an FD who always gets around 70ish counts of knock from regular driving. On my s4 T2 setup I would get ~82 counts of knock every time I hit full boost--and one time I got 82 counts of knock just driving a few miles from my house and never hitting boost!

Personally I've practically given up on the stock knock sensor for my car. But the first thing you could do is check your motor and tranny mounts to make sure they are torqued correctly and in good shape.

 

It's doesn't mean jack ****.
Even FD owners ignore anything below 70.
The Power FC is not calibrated for use with the stock FC knock sensor.
It's basically useless.


-Ted

 

lol, well that's good to know, i was wondering why i was reading full knock in a neutral rev, thanks guys....

since it's not calibrated to be used with the factor knock sensor, is there an aftermarket unit i can use?...

 

What about the ap engineering power fc that has an internal chip for use with the S5 TII and uses the stock fc coils without modifications. Is it calibraded for the stock fc knock sensor?

 

I honestly think the FD and FC knock sensor are the same, just different connector. But that doesn't make it any more accurate. I have been wondering how the placement of the 87-88 knock sensors (middle iron) changes the readings versus the knock sensor in the rotor housing.

Interestingly enough, the Rx-8 knock sensor is apparently the opposite--very insensitive, or so I hear.

 

FC/FD knock sensors are crap. They pick up noise/vibration too easily. Go over a big bump and OMG! 120KNOCK!

 

Yeah, I even have the AP Eng. PFC in my S5 and even right after I got a good tune from Defined Auto., I still had bad knock. I simply just ignore it.