Adding Knock sensor to 3.2L Euro engien

[ewave]

Thanks for all the advice about running a 3.2L Euro engine with 10.3:1 compression in the USA.

I read all the back post of this, and I was warned that even US 93 octane fuel may cause some detonation.

So one solution would be to add a knock sensor and retard the timing. I started with the idea of building something to do this myself, and found a company that sells this product already.

http://www.jandssafeguard.com/safeguard.html

About $450

You install a knock sensor, the unit takes this as an input and sits between the DME and the coil. If it detects detonation it retards the timing for just the cylinder that was causing the detonation. It's pretty smart, as it has an algorithm that tracks all six cylinders and it instantly retards the timing on a cylinder by cylinder basis until the knock goes away, and then slowly eliminates the retard over 20 engine revolutions. It keeps track of this per cylinder.

Apparently the new Porsches and Corvettes do this.

Does anyone have any experience with the "Safeguard" product? I think I'll install one of these on my high compression engine so I can sleep better at night.

[emcon5]

I don't know this for sure, but I understand a knock sensor is difficult on an air cooled engine because the engine itself makes so much noise.

Do they have a kit for 911's?

Tom

[Chuck Moreland]

I'm intrigued. All 911 motors beginning with the 964 have knock sensors, so I guess they work.

They have a horrible web site. From what I gather, they have a universal kit that can be used on any (many?) cars.

They don't show pictures of the knock sensor. I'm curious how it attaches. Drill and tap the case I assume.

[stlrj]

On a 964 the knock sensor is mounted on a fairly sophisticated device that bridges the base of each cylinders in order to read the proper noise signal. How in the world could you duplicate that level of engineering, assuming that the placement of the sensor was that critical? In addition, I am told that not all knock sensors are sensitive to the same frequencies, so you wouldn't want it to mistake the sound of your valve trane or sheet metal for detonation.

The sounds that water cooled engine make must be quite different from air cooled engines too, so the sensors might be sensetive to different frequencies depending on application.

Just some things to consider.

Joe