Hello, my name is Dave James and I've helped two people at my
chapter (#55) build their Mazda powered kits, and I have had the
honor of meeting you at Oshkosh. Besides your web article on
turbo-compound engines, I have just read another in Kitplanes,
and I would appreciate your guidance. I was looking at
turbo-compounding a 20B, but I was overwhelmed by the complexity
and the difficult R & D on the limited budget of a home builder.

When I read your last article about the potential 50% energy
available from the exhaust of a rotary, I was of course excited
and more driven to find a solution. Would it be possible to
couple two 13bs together and pipe the exhaust from the first
three rotors to the combustion chamber of the forth, using a
waist gate to balance the pressure on the fourth rotor to
balance it's torque?

On the surface this avoids so many
complexities of proper turbine size, gearbox, cost, weight, and
dependability, that it seems too
 easy. On the other hand if I can depend on a minimum 33%
pressure from thee rotors, with a tuned pipe lengths for the
proper harmonics, I see an elegant solution.  I would love to
hear your opinions, thank you.

Sincerly Dave James

Yes something like that is possible.

Roll Royce built something similar. The drawback of course
is the increased weight and size. The timing and port area is
adjusted to supply more or less horse power to the supercharger
verses the power recovery chamber.

A TO4 turbo charger on the other hand weighs only 16 pounds.

Keep up the good working helping people build rotary powered
aircraft up there in Michigan. Thanks for doing that.

BTW We have a special on my book "How to Cool Your Wankel"
for News Letter readers. $30 cash (no checks, MO's or CC's)
plus $5 mailing. Send me email with the word "private" in
the subject box for more info.

Paul Lamar