calculation of crank angle position based on crank sensor

[m.s.t.]

I have seen various pressure logs, and I can confirm that knock is clearly visible.
I think it's a good thing what you are doing, but the tuners I spoke to all prefer det-cans instead of pressure logging. Just consider if it's worth the hustle.

Strain gauges can be transformed into 0-5v pretty easy, just use an instrumental amplifier and bridge of wheatstone, which can be found for 10$. The problem is that the megasquirt is just waayyy to slow to log these kind of data, as stated before you need a good, verry fast, reliable daq and crank decoder. At least if you want to do this the proper way.

Can you tell me which company you found for the strain gauges?

[Yves]

http://www.akron.be/

The attachment refers to a firm that did a similar thing but with a sensor below the plug.

Unfortunately they don't make it anymore.

[Yves]

[madbouncy]

Are they just put on externally to a normal plug?

[Yves]

Are they just put on externally to a normal plug?

That's the intention. Remember this is still a test.

The metal jacket of the plug gets stressed because the pressure inside the cyl is trying to force the porcelain insulator out of the jacket. The jacket normally retains the porcelain.

Have to add that the price was a bit of a bummer. A lot higher than what was first mentioned : € 250 per plug + shipping. At any rate still a lot cheaper than anything comparable that can do in cyl pressure measuring.