For all you forced induction guys.

[jdbubb at verizon.net (Dan Bubb)]

Where do you get all this stuff??
4000 of them!

Mine was plastic enclosed, but I cut that open and even trimmed the outside 
of the unit a little.


From: "Jim Ruffi" <sciroccos@earthlink.net>
Subject: Re: For all you forced induction guys.


>I have a couple thousand piezo transducers here if anyone wants to play 
>with
> this project, assuming it calls for round brass disc-type ones with silver
> over a quartz substrate.  I have a couple of different sizes: 25mm and a
> smaller one.
>
> I also have/had these encased in a plastic housing "pickup" assembly, but 
> I
> threw out about 4000 or so of these a few years ago.
>
> Jim
>
> ----- Original Message ----- 
> From: "Dan Bubb" <jdbubb@verizon.net>
> To: "Scirocco List" <scirocco-l@scirocco.org>
> Sent: Monday, July 11, 2005 12:45 PM
> Subject: For all you forced induction guys.
>
>
>> About a year ago I bought this little audio amplifier kit, a piezo 
>> crystal
>> and a set of headphones to construct a DIY audio knock detector that I
> read
>> about on www.autospeed.com.
>>
>> Basically you glue the piezo crystal (converts vibration to a voltage
> output
>> or converts a voltage input to vibration) to a clip that you can clip 
>> onto
>> your engine block.
>>
>> Well, I finally got off my dead ass and built the kit. The circuitry
> itself
>> was nothing, the board is ~1.5" x 1" with 8 components. What took all the
>> time was mounting all the bits in a box.
>>
>> Finally tested it this weekend.
>>
>> It really works. Mostly you just hear a lot of things clattering around 
>> in
>> there.
>> But, pinging/knock is a clearly detectable hard ticking sound.
>> So, as you're hauling ass down the highway despite lots of wind noise,
> lots
>> of road noise, lots of engine and exhaust noise, you can still clearly
> hear
>> the
>> engine pinging.
>>
>> Interestingly, after you shut off the engine from idle, you can also hear
>> the ball bearing turbo spooling down for 20 seconds or so!
>>
>> Anyway, for about $50 and a few hours of assembly time this rates right 
>> up
>> there
>> with a WB-O2 as a tuning tool to have for forced induction engines.
>>
>> Dan