Ignition (Hot)

[jadney@vwtype3.org (Melissa & Jim)]

>From: Toby Erkson <Toby_Erkson@ccm2.hf.intel.com>

>Gas mileage: my engine went from stock FI 1600cc to 2003cc via bigger 
>pistons, longer stroke, mild cam and 36mm carbs so I would expect lower gas 
>mileage -- power vs. mileage, give and take. 

While there are some additional losses that come along with a larger engine 
due to larger piston ring swept area, larger oil pump load, and increased 
crank windage, these are all rather minor in the larger scheme of things.  
In the end your car and mine will call for the same HP from the engine if 
driven side-by- side on the freeway.  Since you quoted city and highway 
mileage, I assumed that this was for typical city and highway driving.  Thus 
your engine must be less efficient at light loads.  This is probably true, 
but it is probably unavoidable.  The efficiency of most engines increases as 
they approach their max HP so while we are crusing side-by-side I am using 
30% of my HP while you are using only 15% (these numbers are just guesses.)

 However, the gains I have are 
>real, not wishful, as I am keeping track.  The ignition came with a 30-day 
>money back guarantee if improvements couldn't be made (Dr. Jacobs is the 
>designer).  You better believe I was going to send it back if there was no 
>improvement!  The only test that I could actually notice was a little more 
>'omph' going up hills.  The time-trial and gas mileage testing are done 
>through a stop watch and logging miles vs. gallons of gas -- not guess work 
>or by what feels right.

I'd like to know how much programming of the ignition timing you can do and 
what parameters the system uses to set the timing.  Does it come with its 
own programming module, or do you program it through your PC?  This kind of 
engine management has great potential for producing an engine that can both 
put out high HP at full load as well as good efficiency at light loads, but 
determining the right multi-parameter timing function for your particular 
engine could be a life's work.

>I am passionate about my T3 and you're Goddamn right I will become 
>defensive when someone doesn't believe me!  What's to gain by lying? 

I did not mean to suggest that you were lying.  It is just very hard to be 
objective about something that you are ego-involved in.  It's not you; it's 
all of us, all the human race.  It's the same thing that makes us swear that 
the engine idles smoother if we change the oil.  It's really silly, but it's 
human nature.

Jim
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       Melissa Kepner                                    Jim Adney
       jadney@vwtype3.org              jadney@vwtype3.org
                             Laura Kepner-Adney
                             Madison, Wisconsin
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