Hi Dustin,
Dreaming is good. There are a lot
more dreamers on this site than there are fliers! You are going to fit in
quite well.
The reason for all those valves and
plumbing on the Renesis is that it is normally aspirated. They don’t
make a turbo for it. It has 10:1 compression so you need to take that
into consideration when you boost it. You could blow it up. Also with
the plane, unlike the car, you basically have two speeds, take off and
cruise. You don’t need to try and maximize the intake for all those
different rpms because you will only be running at, mostly, two of them. The
intake that comes from the factory will not fit under the cowl on a
plane. This means you will have to build your own. If you start
trying to do all the plumbing and valve flipping that you are talking about,
you will certainly need a bunch of friends with lots and lots of EEEEs behind
their name.
You would be surprised at the journey that
this becomes. I started working on my plane in 2002 and it just passed
its Airworthiness Inspection. I still haven’t flown it because there
are still issues that need to be tweeked. Maybe next week!
Good Luck!
Bill B N249B
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Dustin Lobner
Sent: Wednesday, February 16, 2011
10:39 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] - Day
dreaming...
Hi everyone,
I posted this today on the HomeBuiltAirplanes forum. Going to C/P it here
for comments/questions/flaming.
Background, I'm planning on building up a Renesis with a Turbonetics turbo,
putting it into a Mustang II. I'm planning on using MegaSquirt 3 (or
whatever is available when I get there) ECUs. These ECUs control things
like waste gate management, any servos you want, in addition to the the EFI and
ignition.
So... <copy-paste from the forum>
The Renesis has 6 intake ports (I think a 4 port model was made for awhile, but
I'm going to buy a crate engine so that's out). I found a white paper
somewhere, written by the designers of the Renesis, talking about each port.
There's the primary, which is always open. Secondary comes on 3,500-4K RPMs-ish.
Aux turns on at 7.5K RPMs. The ECU I'll be using has outputs for controlling
things like butterfly valves for different intake runners.
My understanding is that most people simply run on the pri/secondary only and
plug the aux, or run with them all going. Seeing as how I'll have an ECU to do
some work if I want, what do people think about valving either the aux or the
secondary and aux? The ECU is flexible regarding mixtures and whatnot, so I'm
thinking I could tune the "cruise" setting for 6K RPMs, aux closed,
and then tune the "max power" setting for 7k RPMs with the butterfly
opening at 6800 or something. Wastegate (should I go with a turbo) can vary by
RPM too, so I could have it set for "normalize" 6800 and below, and "boost
the heck out of it" above that.
*Shrugs* I know, it's an airplane, KISS. I have a few years before I'll be to
the point of being able to wrench on the engine, so I'm dreaming about it now
and hashing things out now so that when the engine gets here I can just build.
From discussions on the Mazda list, different length runners DO matter quite a
bit, so it's not like this is a completely worthless thought.
Thinking about it, valving the secondary seems a bit stupid, because if that
valve breaks you don't have a good portion of your power, whereas if you lose
the aux it's not the end of the world.
<end paste>
I guess what I'm going for is, I remember some conversation here about
different length runners for different tuning. This could let you have
the best of both worlds...thoughts? And mind you, I have a two engineer
aviation minded friends, one with a ME/EE double and one with an AeroE, so I'm
not completely without help designing this.
Dustin