Real time dyno

[Todd Knighton]

Now, just to throw a curve at all you guys on this thread.  When we
calibrate engines on the engine dyno, we typically use the dyno for a
load device only.  We load the engine to a specific load / rpm site and
calibrate the engine for the air/fuel ratio desired, not the one that
makes peak power, but the one that over much pain and aggrivation has
produced the best reliability / performance / economy / in other words
compromise over time.  Then the timing is adjusted to it's optimal
value, again for no knocking nor misfire because of rotor phasing, etc. 
Sometimes timing is checked for optimal power, but typically fuel is
not.  
So, the acceleration thing, is not only not practical for on the road
use, but doesn't really give much results either.  
We usually only power test the engine once all the tuning is done.
Especially if you're doing a normally aspirated engine, the differential
results from changes from run to run are typically hard to tell from the
errors accumulated from environmental factors.
Oh, and are you guys going to factor in your correction factors for
humidity, barometric pressure, and temperature to give the results from
run to run more accurately?
All I'm trying to say is, don't expect miracles from the readings off
the accelerometer.
An EGO sensor and a knock sensor from J&S with a monitor will get you
calibrated 10 times faster.  Don't worry about the changes till you're
done then record the results and get a graph or something.  The basic
engine combination is more of a factor to record changes, the tuning is
just set up for a specific engine combo.


Todd Knighton
Protomotive Engineering

> Since I don't, and my needs are tuning my EFI for optimum (in real
> time), the accelerometer seems the best compromise.  I don't have
> to pull the engine, or pay someone to let me use their dyno while
> trying to make adjustments.  Clearly, I'm not trying to compete.
> If I were, I'd seek out the likes of Todd and follow their lead.
> But, their methods are beyond me.  Methinks if I could just peak
> acceleration and then tune for some other trifling things (like
> idle, cold running, etc), I'd be happy.
 
> tom