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