Paul and Don,

                   Here's the Turbochart spreadsheet.

                   If you have any questions about using it, or suggestions
         to improve
                   it please let me know.

                   I'm in the middle of completely revamping it to add the
         exhaust
              side
                   so we can match turbines for turbocompounding. I also
    want
         to make
                   it easier to use.

                   Regards,

                   Gordon.

         Thanks Gordon,
         This spread sheet is very helpful.  As I started plugging in
    numbers for
         my 20B, I wasn't sure what numbers to use for the following:

         Volumetric Efficiency
         Air-Fuel Ratio
         Compressor Efficiency

         I sent the spreadsheet back in this e-mail with my number saved
    in it.
         Can you look at it for me?  All my little colored boxes seem to
    fall
         outside of the graph.  The GT4202 Turbo Chart seems to be
    closest since
         the colored boxes are at least inside the graph.  Am I doing it
    right??
         What does all this tell me?
         Don



    You will notice immediately that I failed to correct the engine
    displacement for the 20B to the number Paul gave me in a prior e-mail.
    It should be ~240 cubic inches.  Unfortunately that made all my numbers
    look even worse on the charts.  I spreadsheet came with a volumetric
    efficiency number of "1.2" already entered into the box.  This sounded
    odd, so I did the almighty internet search.  I came up with this site
    that indicates that the more appropriate number should be 0.94 (94%).
    Does this sound correct?
    Don

    http://www.digi-go.biz/articles/volumetric-efficiency-of-a-rotary-engine-explained-by-miguel-p.html

    -------------------------------------------------------------
    You should notify the guy that did that we are here to help :)

    The 1.2 VE number is for a P-port. .94 VE is more like it for  a 2nd gen
    side port. The side port  RX8 engine with the stock tuned manifold
    is about 1.05 VE. A lot depends on the manifold so .94 VE might be high
    for a 3 rotor. It is called Ram Charging or some such and was developed
    years ago. Made famous by Dodge. Something for nothing. It is
    a pipe resonant phenomena.

    Please send us your sheet again when you get it fixed.

    Paul Lamar ...No rotor no motor.

    The Rotary Engine NewsLetter. Powered by Linux.
    ACRE NL web site. http://www.rotaryeng.net
    Copyright 1998-2006 All world wide rights reserved.

Paul,
Here's my updated spread sheet, but as you see, something is not working
out correctly.  I entered a desired horsepower of 350 but the sheet
shows actual hp of 410.  Its also showing 41.8 gph for fuel consumption,
which I hope is wrong!!  The sheet actually shows fuel burn in 3
different locations and each is significantly different.  Not sure why.
I still don't know what to enter for compressor efficency, but the sheet
already had 0.7 so I left that number alone.  Hopefully I'll hear from
Gordon and he can help me work this out.  What do you think?
Don

At 350 HP the fuel burn will be about 32 GPH at a BSFC of .55.
Fully leaned at 250 HP it will be 20 GPH at a BSFC of .47
Most guys with the 13B are cruising around 150 HP or 12 GPH.
The turbo compound version will be up to 20% less at
altitude.

Paul Lamar ...No rotor no motor.

The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.