How are you calibrating / adjusting for water injection AFR?

[Forum Admin]

With a properly implemented water/methanol injection system, you should be able to arrive at maximuum power AFR and MBT without ever experiencing knock.

I tune without water injection to the threshhold of knock and then pull back a bit to find my base tune that I revert to in the case of a WI system fault.

Generally I only monitor for knock during tuning - I use this:

http://home.netcom.com/~bsundahl/kno...nockSounds.htm

And the DIY knock cans:

http://home.netcom.com/~bsundahl/kno...ten/listen.htm

I attach this to my tuning computer while tuning.

Of course I am relying on my ECU's knock sensing / timing retard response if I cross the edge somehow.

[Philip]

Thanks, that seems the easiest to use and I could just keep an ear peice in whilst tuning and listen out for anything unusual. Would be a very nice facility and peice of mind whilst tuning. Where would you recommend putting the mic? I have a V8 so would it be possible to bolt it onto the inlet manifold?
Thanks again really pleased with that suggestion as it would be very cheap,
Phil :lol:

[Forum Admin]

This particular DIY relies on a factory knock sensor and taps into its signal. I use my laptop amplifier to listen in.

Another DIY that includes information on building one with a microphone -

http://www.autospeed.com/cms/article.html?&A=0353

If you do not have a factory knock sensor the mechanical one brad mentioned also works very very well and likely would be easier than building one with a microphone unless you already have the audio electronics skills.

You can get a stethoscope and tubing routed to a 4" copper tube with 2" flattened and a hole in the end for bolting to the engine.

The intake may work but attaching to the block would be preferable.

[blown408]

I made that DYI unit it works great and it is very cheap to make, try radio shack.