Engine Software (was Re: Mike Sargent, where are you?)

[Tom Cloud]

>Tom,
>if you would like to see and feel desktop dyno for yourself, i live across 
>the street from UT (i noticed your email address) and you are welcome to 
>try it.

Steve, I just received Engine Analyzer.  It makes nice graphs and
prints out reams of figgers I know little about  ;-)  It crashes
WIN95, so I have to re-boot in DOS mode to run it, but I can
print out the graphs and all.  Can lay the graphs over one
another to do comparisons.

One thing I know I don't know (i.e. I recognize there's much
I don't know I don't know) is how to re-figger CR when changing
heads.  There are several heads that come with the software, but
when I change to one with a different combustion chamber volume,
I notice the CR stays the same.  Another problem is finding
specs on cams.

I have observed that the biggest gains come from opening up
the intake with larger cfm carb and better intake.  The choice
of head seems to have maybe 1/5 the effect and the exhaust is
even less than that.  The software also let me better visualize
what I'd always known had to be true -- the torque/hp curves all
start at zero (well, that's obvious), and sorta track till
rpm gets up (not including wild cams).  Some manifold/cam
combos drop torque off at low end and cause peaky curves,
but most that I'm interested in (for a truck app) seem to
mostly either move the torque peak back a few hunnert rpm
or make the hp curve keep climbing up to 5500 or so (which
means the claims of additional hp really don't buy anything
if one never does 5500 r's).

Anyway, didn't get Desktop Dyno, got Engine Analyzer.  Now
I wish I knew enough to use it  8-)

Tom Cloud <cloud at peaches.ph.utexas.edu>