|
I could open them. Read the one on Turbocharging and
didn't find anything in it that bothered me. Some good points
including what we have already proven, that the Stock Mazda Turbo
charger (just about any stock auto turbo) is simply not designed for the
demands aircraft use puts on it. Also why intercooling is something that
needs to be seriously considered in aircraft us.
There are certain benefits to be gained from a turbo -
having turbocharged two automobiles back in the mid 70s, I long debated sticking
one on my Rotary powered RV-6a in which I also have a turbo block san the
exhaust splitters. But, after calculating that the turbo, intercooler and
wastegate would add at least 50 lbs up front and plus the fact that in my case,
I would seldom use it - except perhaps for take off, I concluded there was just
nothing (in my case) to justify it.
Once I switched from the 2.17:1 and 68x72 prop to the
2.85:1 74x88 prop that provided the increase in take off acceleration and
performance I was looking for and that sealed the decision not to go
turbo.
However, I certainly think that those who find
benefit (or simply want to) in turbocharging can safely do so. Dave,
John, Steve and others have shown that it can be done at a reasonable cost and
relative light weight installation.
A couple of things you may find and should be prepared for
with a turbo installation - more power = more heat, so if your cooling system
was on the border line cooling an N/A engine it may find the additional heat
generated by the additional HP especially on take off something you need to
watch. Also the heat build up under the cowl can greatly increase - some
folks have gone to coated exhaust systems and you should be particulary vigilant
in shielding any fuel components from line of sight exposure to exhaust system
components.
Your engine should easily make 200 HP with the turbo and
you may find that your engine is a bit under-proped with the prop you have
now. I had a 68x72 and probably did not produce much over 160-170 HP and
could hit over 6000 rpm in flight.
So looking forward to hearing about your first
flight.
Ed
Sent: Sunday, October 17, 2010 1:40 PM
Subject: [FlyRotary] Re: The Case For
Turbocharging
Kelly:
Maybe I'm a bonehead, but those zip files didn't include anything readable
for me....
On the other hand, I'm using a Turbo on my RV-8 prject, so I'm in as far as
selecting a turbo.
I finally decided to use a turbo because of Tracy's muffler experiments. I
have a Turbo engine, with the open exhaust ports, so the sound pressure is very
high and would require an extra strong and tough exhaust system (heavy). So I
decided to use that weight in the form of a Turbo to knock the most vicious
element form the exhaust noise. I hope for a higher rate of climb as a
result of the increased power potential.
I realize that all engines have a sweet spot that would be best for cruise
and range, which would co-incide with the engine torque peak RPM and an
airspeed less than Vne, so sustained high turbo boost is not practical or
desired unless 25 gallons per hour fuel flow is expected! That's a pretty short
flight with 42 gallons total fuel aboard.
I set my goals to a more attainable level, with a prop that should
draw about 200 HP at 6500 RPM. It's a left hand turning equivalent of the
prop for RV-8s with a 180 HP O-360 Lycoming. I have Tracy's RD-1 2.19:1 4
planet gear, so I don't plan to abuse it past the 200 HP limit he has
established. I simply calculated the prop power draw 180HP / 2700RPM =
200HP / 3000 RPM.
By the way, for you prop chord measuring guys, it's a CATTO 2 blade
68x74 prop, with the greatest chord about 6-3/16" falling from 16" thru 20" in
from the tip, which is right in front of the cowl cheek edge.
This last week I put the wings on and set the incidence, made the fuel tank
attach brackets and fit the flaps & fairings. Now the wings are back
off, getting the fairing platenuts etc.
I'm not that far from taking the whole caboodle to the airport!!
-----Original
Message----- From: Kelly Troyer <keltro@att.net> To: Rotary motors
in aircraft <flyrotary@lancaironline.net> Sent: Sun, Oct 17, 2010 9:50
am Subject: [FlyRotary] The Case For Turbocharging
Group,
Perhaps of interest to those us interested in
Turbocharging our projects..........It
is from the "SDS" website.............
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil
Manifold
"TURBONETICS"_TO4E50 Turbo
|