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Knock Sensor on Megasquirt?
MakeEverything - 10/7/10 at 07:48 AM

As title, does anyone know if its possible to put a knock sensor onto MS2 V3.0?

I cant find anything in the megamanual, just wondering if those more experienced know anything.


flak monkey - 10/7/10 at 07:53 AM

You need an amplifier.

What I will say is that I wouldnt trust one....

I would much rather use something like the kit from Phormula (which I do!) which lets you listen for knock yourself, then you can set up warnings and thresholds at different levels for your engine. Seems to work very well.

Once the engine has been set up properly its not really necessary to monitor it anyway. And in any case I would always get a forced induction car set up on a rolling road for piece of mind.


MakeEverything - 10/7/10 at 08:26 AM

OK, Thanks David.


turbodisplay - 10/7/10 at 09:18 AM

Knock snsors are important, especially whan running high boost on high compression engines.
The main problem I find is that any metal rattle caused by a loose parts, exhausts touching the chassis etc can look like knock.

Carbon buildup / bad fuel/ intercooler cloged up...... can cause a good engine setup to knock.

The knock sensor needs to be tunned to the resonant frequency of the chamber, 86mm bore is 7khz. Some knock sensors are internally tuned to the bore frequency, some have no filter (needs to be external).
Some v8s run knock sensors with a similar bore to 93mm.

Darren


coozer - 10/7/10 at 01:07 PM

My St170 engine has a knock sensor as standard, but as said its needs a conditioner to run with MS.

Other option is to construct a little circuit and have a row of LEDS on the dash. Seen it on a westy but aint got a clue how to do it


matt_gsxr - 10/7/10 at 04:03 PM

I built one of these put the microphones on wires and mounted them on the engine with clips.

Not as fancy as the Phormula kit, but the same principle, and locost;
http://autospeed.com.au/cms/title_DIY-Detonation-Detector-Mk-II/A_1353/article.html




I got the idea from this
http://autospeed.com.au/cms/title_DIY-Detonation-Detector-Mk-II/A_1353/article.html


Matt


coyoteboy - 30/7/10 at 01:16 PM

There's a far simpler solution in a car with a stereo (which migh be blaspheming on here) with an aux-in (any decent stereo) - just feed the knock sensor output into the head unit inputs. Use the graphic equaliser to rip out all but knock-range frequencies and you can drive around all day listening to your engine knock problem without building or buying a single PCB. I road-tuned my 3s-gte this way on an MS1-extra setup.