On Feb 5, 5:30*pm, DonMorrisey wrote:

Well that's the great thing about experimental aviation, we can agree
to disagree. *Powerflow Exhaust systems are proven to add
considerable power...

I'd like to see a credible cite for that rather sweeping assertion.
The way I understand the situation, the PowerFlow exhaust restores
power detracted by the distinctly suboptimal exhaust installations
used in a variety of certificated airplanes such as PA-28, AA5B, and
C-172. Further, the system is STC'd so the installation paperwork is
minimal.

However, I don't think that there is any data to suggest that the
PowerFlow holds any measurable advantage over a Vetterman or similar
crossover system as found on a typical experimental airplane.

Thanks again, Bob K.