Home-brewing an ignition advance control

[Bruce Plecan]

-----Original Message-----
From: am018 <am018 at post.almac.co.uk>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Tuesday, October 27, 1998 4:15 PM
Subject: Re: Re : Home-brewing an ignition advance control


>I missed the start of this thread  -- I am pretty interested as one of the
>ideas I am kicking around at the monent is a knock retard device for
classic
>50s & 60s cars designed to run on 101 octane fuel what we called 5 star in
the
>UK    --- basically idea just to put  few degrees spark delay in when knock
is
>detected. The first part is a simple stand alone knock detector module. I
know
>things like this have already been done but as far as I know none is on the
>market at the moment.

MSD, and J+S sell them.  Also could use a gm knock sensor/esc to
trigger a MSD multi step retard.
Bruce

>Andy Macfadyen
>
>Donovan_Dibble at ittauto.com wrote:
>
>> Al,
>>
>> I've been thinking of making a similar system.  I want (am) going to use
a
>> PIC 1674 uP for the 'brains'.  This micro has built in A/D for MAP, TPS,
>> etc.
>> This will hopefully make the system more compact.  Although I haven't
>> worked
>> on it in a while, I planned on starting by collecting data from a
'regular'
>> HEI distributor with vacuum/mechanical advance and simply implementing
that
>> strategy into the micro.  Later, the knock sensor input and associated
>> retard
>> logic would be added.  I think the easiest (or most straightforward) way
of
>> detecting knock will be with external op-amp filters rather than
>> calculating
>> Fourier Transforms within the micro.  Any signal conditioning would also
be
>> taken care of with the op-amps.  I got as far as getting the vacuum vs.
>> advance data for the HEI but haven't taken it any further.  If you or the
>> list
>> have any other ideas, I'd like to hear them.  Any motivational ideas
would
>> be
>> welcomed too :)
>>
>> Don
>>
>> >I have been pouring over the HEI 4-pin and 7-pin diagrams and info on
this
>> >page.  The amount of info that is to be found on this page is FANTASTIC!
>> I
>> >am trying to figure out how to make an ignition advance control for a GM
>> HEI.
>> >I know MSD sells one but I would like to make my own if possible.  It's
a
>> lot
>> >more satisfying that way and I learn alot more.  Is this done with an
>> >adjustable timer IC or is it some other kind of signal conditioning.
>> >
>> >Any Ideas???
>> >
>> >Thanks for listening
>> >Al Ross
>
>