Bryan
I can’t
really answer that question as I don’t know the details of Ed’s design,
and there may be differences that neither of us understands.
My induction
system is shown in the attached photo. A ram scoop feeds (through a
screen filter) an air box that I made from fiberglass. It provides
smooth transition (in lieu of air horns) to the TB which has 44 mm
barrels. Then divides through a custom short manifold to the rotors. On
set of injectors in the TB, the other stock injectors in the side
housings. I run the injectors in the TB as ‘primary’ because they give
me smoother low end operation.
George – I
don’t recall don’t any detailed analysis in choosing the TB
diameter. I did look at the air velocity, and discussed with
Paul
Yaw and David
Akins; and made a ‘best guess’ for good breathing, and good throttle
response coming off low end.
A lot of
discussion is made of tuned induction and exhaust, however; my primary
consideration was simplicity and compact installation for both. The
system gives me easy start both hot and cold; and dyno tests show very
flat torque response from about 2500 rpm all the way to 7000, with the
corresponding nearly linear rise in HP to 300 hp at 7000 rpm. Just
started to see signs of a break in the power curve at 7000 – which is as
far up as we tested. This engine has the 9.0 : 1 compression turbo
rotors.
It is likely
that longer runners, higher compression rotors, tuned exhaust could get
some more horses, but I have all I need for the application. If
you look at reinforcement of
intakes pulses on a 3-rotor, it turns out that the 12-13” that I have
from port to air box is a good distance at 5500 to 6000 rpm. I made no
effort to design the air box to direct these pulses, so whether I get
any help from that is open to debate.
So that’s
about all I know. I’m happy it worked well on the first try.
Good luck on your Renesis.
BTW; the
intake manifold is 6061-T6 aluminum, weighs only about 2 lbs. It was a
serious challenge to fabricate. Fortunately, on the third try, I
found a very skilled machinist/welder who got it port-matched at both
flanges, and got the thing welded up. I then took it to a heat
treatment shop, and had it heat-treated back to T-6
condition.
Al G
--- On Sat, 2/7/09, Al Gietzen <ALVentures@cox.net>
wrote:
From: Al
Gietzen <ALVentures@cox.net>
Subject: [FlyRotary] Re: renesis
intake possibility
To: "Rotary motors in aircraft"
<flyrotary@lancaironline.net>
Date: Saturday,
February 7, 2009, 3:04 PM
I use a
3-barrel TWM TB on my 20B with 44mm barrels. One barrel (which
divides into the 2 runners) for each rotor. It seem to work quite
well. As Ed mentioned, and supported by Paul
Yaw¢s work,
high velocity in the barrel is a good thing. Maybe you could cut the
thing in half and use 2 barrels? I use the injector port in the TB for
MSD (Rochester)
injectors, and use the stock primary in the
housings.
Al