I am doing a T4 turbo upgrade on my S4 TII motor. The engine will be controlled by the Power FC using the Banzai adapter harness. The engine has been swapped into my S4 convertible, using the convertible's original NA harness. Due to the two wiring differences in the harness, I deleted the knock sensor at the time of the swap since it isn't very useful on the stock motor. Now that the power level is going to be more than doubled, I am looking for input on what to do about a knock sensor. Should I:

Continue without one?
Wire in a stock TII sensor?
Wire in an FD sensor? (IDK if this is even feasible)
Install an aftermarket sensor?

I am a newb to the Power FC, and I know that this isn't a common application for the Power FC to be used in, but any help would be appreciated. I need to try to stay cheap if possible, at least til after my tune in November. I have all winter to change over to the best option I can get by cheaply for now.

 

I have created a guide for FC owners who have or plan to use the Power FC on their car. I suggest you check it out: http://www.geocities.com/arghx/PowerFC.FC3S.Tuning.doc . It is also available in the files section of Chuck's Power FC Yahoo! tuning group . You can PM him about membership ( cewrx7r1 )

It is my understanding that the FD and FC knock sensors themselves aren't really any different. On my s4 T2 motor, the stock knock sensor was completely useless. It was just too noisy. There was a reason why they relocated the knock sensor from the center iron to the rotor housing in all s5 and later models. I don't think you're missing much by not having it. You're better off going aftermarket.

 

The only difference in FC/FD knock sensors is the connector. You can install one of the OEM units, I would not suggest installing an aftermarket unit as the PFC may not know how to read it correctly.

Arghx-sending a pm on your doc

 

I did not mean to imply that you would hook up an aftermarket knock sensor to the FPC for display purposes. It would have to be a completely standalone knock sensor system independent of the PFC.

 

Also you would have to run a shielded wire to the sensor from the ecu, you cannot use the N/A solenoid wire that runs to that pin on the engine harness.

 

Thank you for that point, as it had already crossed my mind as well. So are you with arghx on this one, as far as me getting by with no knock control unit, for now or indefinitely?

 

the PFC does not have any knock retard function. The knock sensor is for datalogging purposes only.

 

i would suggest u hook it up and monitor it for your own peice of mind, bad fuel can register knock on the power fc, so at least u know to ease up on the the boost.

 

You do not need a knock sensor for the car to run, but it is not difficult to install so I would put it in if you have it laying around.

 

So just for my own final double clarification,

1) If I want to hook up my knock sensor, I need to connect the sensor itself directly to the KS wire on the Banzai adapter harness via a shielded wire? (remember, my car's wiring is S4 n/a, and is not wired for the knock control unit) Is the knock sensor only 1 wire?

2) Connection of the knock sensor will result in loggability of knock via datalogit, but will not adjust the tuning parameters to compensate for a knock reading?

Is this all correct??

 

Yes and yes