Paul,

 I read about P Porting on the turborx.com site, and they say that

 1.  the engine won't idle much below 2000 rpm
 2.  shorter engine life
 3.  "needs an exhaust system designed to produce excessive noise"

 As I recall, the 13B can produce about 180 HP at 6K [with PP?]
 and perhaps 250 HP with turbo and PP at 6K rpm.  I hope I am
 remembering those correctly.

 Anyway, if I wanted to retain better idle characteristics, and also
 wanted a very QUIET exhaust system [like a car], what HP could
 I achieve with just a "mild" or "street" [side] port and turbo?
 Thanks again.

 Gene Kahn


 A p-port RX8 engine idles just as well as an old perip
 exhaust port 13 B engine.

 Forget all you know about auto engine RPM. A rotary is
 just getting started at 6000 RPM.

 They are wrong on both counts. The p-port engine will produce
 300 HP at 9500 RPM. A turbo street car engine can and has  been
 built with as much as 450 HP.

 How quiet it is for a street car depends only on the muffler.

 It all depends on how much HP you want for your street car.

 Paul Lamar



Sorry, Paul...I did not mean I wanted this for a car...
I just meant I would like it as quiet as a car.  This is
an aircraft application.

I was just wondering what power I could get from
a mild street ported and turbocharged 13B?

Thanks again.

Gene Kahn


It all depends on the boost. The engine will out last the
turbo charger as long as you don't let it detonate. We don't
have any good data on the lives of aircraft turbo chargers  for
rotary engines (higher exhaust heat) as some people (they know who
they are :)) have not installed turbo charger tachometers unfortunately. Consequently you would be on the bleeding edge. I'll be glad to
work with you on it if you are willing to allow me to install a
turbo charger tachometer on the turbo charger you choose so we
can sneak up on the problem. :)


The problem with NA side ports and turbo's is you won't find any suitable
intake manifolds low enough to fit under a cowl. If you attempt to build
your own they will cost more than a p-port and be less than perfect.
There are at least half a dozen different intake porting systems
so it is no longer cost effective to build cast intake manifolds
for all the possible configurations. We used to sell a suitable manifold
for side port engines and we gave up when Mazda changed the
configuration yet again with the RX8 engine.

We are now sold out for the four port version we were building
and selling. IMHO it is best now to p-port everything.

Here are some old pictures of our old turbo engine manifolds.

Paul Lamar