Attention Dave Leonard,

Want to help Paul and everyone out?  I suggest you buy one of these cheap
laser turbo tachs.  This one is  40 pounds sterling but you can probably
get it cheaper in USA via Asia direct.

Paul will show you how to separate the components so you can have the
display in the cockpit and the sensor aimed at the compressor blade
inlet.

http://www.gyroscope.com/d.asp?product=TACHOMETER2

Might be a kit available now as laser scanning has become a ripe
technology.


Doug in Japan

I am available to help at any time Dave.

Paul Lamar


I have to admit that I cant really see what enlightenment you hope to
achieve by me installing a tach turbo.  Really.  The turbo maps are all
readily available and give a very good approximation of the turbine speed.
RPM and MAP are well known quantities.  To get mass airflow you only need
volumetric effieciency, but that is a small unknown and varies with each
installation anyway.  So right now we know the turbine speed within 20% on
the far outside, probably much better.

But suppose you had a more accurate number, big woop.  We still know nothing
more about what the tubine blade can withstand - long term, short term, and
how that varies with temperature.  To do that you would have to take a lot
of turbines to failure...  Not worth it.  John Slade and I have alread
provided the data points that are actually useful:
1) yup, as expected the stock turbo will not last very long
2) bigger, slower turning turbos seem to last longer
3) running at peak EGT all day is not very nice to the turbo either.

I'm afraid that if Paul is going to continue to insist on not finishing his
airplane then I am not messing around with a turbo tach.  However, I will
make this promise: When Paul finally finishes his rotary powered KIS, I will
install a turbo tach and provide you with a number somewhere around
100,000.   :-)