How does the OEM 997.2 knock control work? Does anyone know? Are there sensors on each cylinder or per bank? How is the sensitivity, and do you agree with this sensitivity?

Knock retard is per cylinder so I'm assuming it is somehow able to hear knock per cylinder?

Is Cobb or GIAC able to control the sensitivity settings?

 

One knock detector per bank, IIRC.

The per cylinder retard is accomplished by the DME noting the time of the signal from the knock sensor, and which sensor, and matching that with what cylinder on that bank is at its power stroke.

The sensitivity is I think pertty good. I've never heard of a stock engine suffering from detonation damage/failure. And the word is Porsche runs its engines at incipient detonation to be able to use as much advance as possible when possible.

Can't help you regarding the question about Cobb and GIAC.

 

In our software we have the ability to adjust the thresholds. It is a per cylinder correction that gets applied. We generally only suggest adjusting them if the motor is built or tuners are confident it is false knock.

EDIT- You can datalog each cylinder knock with our software. I am unaware of any other software that can do this on a 997.2 Turbo.

The 997.2 is nowhere near as sensitive as the 997.1 Turbo.

Thanks,

Mitch

 

Thanks Macster and Mitch. Very helpful.

 

Have you ever seen anything but 0 for knock retard on factory tune when using 98Ron/93 USA?

 

On the 997.1 with 93USA I have seen up to -5.5 Deg per cylinder depending on IAT temps, load, etc.

This is on a stock map with a free-flowing exhaust. I would think the 997.2 is similar.

 

The 997.1 is a lot more prone to knock detection.

You would be surprised how much knock we have seen on the stock calibration when datalogging.

-Mitch

 

False knock yeah? Like if you listened for knock the dyno the old school way (physical listening device / mic) you don't hear it. Do you see the same sensitivities in the 991 TS vs 997.2 TS?

It's interesting the way Porsche setup the sensitivities though. Maybe they think the 9A1 engines are better?