If the six ports didn't make more HP, then Mazda wouldn't
have gone through
the trouble and expense to make them.
In an airplane, as long as it can idle, you don't care about low-end
torque.
The prop absorbs HP proportional to the cube of the RPM. Thus, you are
spinning mighty fast before any torque to speak of is required. At that
point, you are on the curve for the manifold with all the valves open.
Indeed, the six port needs a properly tuned manifold to make the extra
HP.
If you are going to put a simple log on the end of some short runners,
then
there is no point of using a six port because the four port will make
the
same HP.
It will be a few months, but we shall see what HP I get when the dust
settles. :^)
Bill Dube'
If everyone had the same capability on the intake design and
fabrication skills that you appear to have then the answer to the
question would be: everyone should us a 6 port because it is more fun,
more difficult, will take longer, will cost more and may have more
power, than a 4 port, in the remote event that the engines being
compared have stock internals.
However, that was not the question.
Anyone who suggests Pporting the new engine sounds to me like a
novice about to make a high dollar mistake.
The short apex seals will not survive crossing the Pport with
adequate life span. I have yet to see anyone bother to Pport one. Some
folks buy the rotors to get the lighter weight, but they recut the seal
grooves to use the 3MM seals.
The 4port version can produce enough power to win the Sun 100,
anytime its run. As Tracy can advise. It can do well even with a less
than ideal intake system.
So, everything you said is true. I support you 100%.
Lynn E. Hanover