[TR] zenith or su's ?

[Randall]

> They sell Air/Fuel mixture gauges that are cheap enough 

Unfortunately, the cheap ones don't tell you what you want to know.  They
are only accurate right at Lambda = 1.0; which is neither best power nor
best fuel economy.  "Wide band" sensors are available, but are substantially
more expensive.

> If you could get a throttle position sensor or something like 
> a rheostat hooked up to a rig like this it would be very informative.

But, throttle position doesn't directly translate to piston position.  You
can infer piston position from throttle position & engine rpm (with maybe
some correction for altitude/air density), but it varies with your
particular setup and how are you going to calibrate it?

These are exactly the same problems one faces when setting up a fuel
injection system.  You need to know the actual airflow into the engine to
know how much fuel it needs.

-- Randall