ION knock detection

[Sandy]

I would be careful of any CDI systems that are do-it-yur-selfer. I have
seen a bunch that are lame, I have not seen the dick-smith one, but a low
budget CDI is worse then a regular high-perf ignitions. I think that it has
to do with the spark duration, which if too short can lead to bad knocking
sounds and loss o' power. I saw an article by international rectificer that
compared a 'typical' (Read low cost) CDI system vs a standar ignition
driven by an power mosfet. The CDI performance was much less then expected,
as the spark duration was much too short to get the fire started. The
comparison was given worst case situations how well do CDI's really works
vs worst case standard ignitions. Also they checked the ultimate energy and
found that for a given # of amps the spark energy was much higher then the
CDI. The spark duration was the key that was stressed at being way to short
with the low-budget CDI. 

This is all from memory from an old IR app note, so take it as you will, or
take it as you won't ;-)

Not this is not true for REAL ignitions, (Plug) M&W's stuff looks very
good, as well as the MSD's, Crane, etc.

Sandy

At 04:22 PM 5/20/98 -0700, you wrote:
>On Wed, 20 May 98 16:46:53 , "John C. Lagerquist" <vision_a at srv.net>
>wrote:
>
>>On Wed, 20 May 1998 11:09:22 -0700, garfield at pilgrimhouse.com wrote:
>>
>>>One thing I AM confident of is IF you wanna build a CDI system (Dick
>>>Smith in Oz sells a pretty decent looking kit for one, #K3307 if my
>>>notes are right)
>>
>>Where can I get some more information on this kit?  
>
>RATS, another brainfart; forgot the web page:
>	http://www.dse.com.au/
>
>Unhappily, their catalog isn't available thru the page, so you can't do
>a search to check on their part nos. I got this outta a magazine advert
>some time back. Best if one of our aussie mates gives them a call to
>confirm part no., availability, and price. Anyone in or near a Dick
>Smith, so it won't even be a toll call? They have 30 stores in Oz, so
>someone must be near one.
>
>Gar
>