http://www.aerocharger.com

Ed Carver  brought by his Aerocharger on a recent visit to
the hangar.

Somehow I missed the fact all these years that is was a variable
vane turbo. Apparently a well kept secret in the turbo charger world.
How I missed this fact I will never know. Perhaps they have good patents
and nobody wants to talk it up. If it works as claimed it will put
all the other turbo guys out of biz.

This unit is ideal for turbo charging an aircraft
engine as you can slow the prop RPM with higher prop pitch
and boost the HP at that RPM with the variable vanes.

It is also ideal for turbo compound.

The convoluted design of the turbine housing leads to a cooler exhaust
impinging on the vanes and the turbine wheel. The bearing oil supply
is also self contained. No engine oil required. One could probably use
turbine oil and have a separate oil cooler system if necessary.

This is a very innovated unit indeed.

"VATN is a series of variable-vanes that optimize the flow area of the
turbine
by adapting to the exhaust gases. By doing this, the turbine wheel is able
to
operate at peak efficiency throughout a wide RPM range, something that has
never been achieved before. This also eliminates the need for a wastegate,
which conventional turbochargers rely upon to control boost. Instead, the
vanes
automatically adjust the flow area and backpressure to perfectly match the
torque requirements of the compressor wheel to produce the desired boost.
Eliminating the need for a wastgate means eliminating extra cost in your
turbo
system"



Paul Lamar


Hi Paul

I have been very interested in the bearing assembly and lubrication setup
on the cool side.

Cheers

Steve Izett

Paul,
What series "Aerocharger" does Ed Carver have and what is the compressor
trim.......Also does anyone know
if the "Aerocharger" turbine wheel and varible vane system will live under
the
Rotary's hot (up to 1800 f) breath ?

Kelly Troyer


I'm hoping someone actually knows about the temp limits of the vanes. The
whole aerocharger design has heat control in mind. The turbine scroll has a
coating on the iron, or so it appears. The exhaust heat is never focused on
one area as is the case in a regular turbo. The design spreads the heat
around a far larger area and keeps the pressures much lower at any given
point.
My intent in purchasing and using this is not to get high boost, but simply
to maintain the minimum power necessary to stay at cruise speed up to 17 to
18k feet, which should be much less than 150hp for a cozy 4. Because I am
using P ports, my base hp is near 250hp. I believe I have read that there
are some cozy 4 flying with 150hp rated o-320s in them and do quite well.

The point is, I don't really need 200+hp, and therefor, the heat factor
will not be at max temp for long durations. I could never use the max power
generated from my turbocharged p ported rotary; so I am building for
efficiency, and aerocharger has some very favorable design features.
a. No oil lines to feed it.
b. No waste gate.
c. No hot side shaft seals to blow, therefor, no oil loss.
d. Designed turbine speed gets the work done below 90krpm
e. High exhaust throughput (low restriction) when the vanes are in the open
position.
f. Manual boost control by adjusting vane angle using the control shaft.
g. Relatively simple exhaust tubing.
h. Can be mounted in many different positions.

Will the vanes hold up?
They probably will.
We shall test it at operating power to see.
I can hardly wait!
But that's my feeling about the whole project.
Really though, I can't tell if the thing will work for 5 min. until I try.

Regarding the question about which model I have?; "it's the big one". They
sell two sizes, and set them up for different applications. I hav'nt
measured the turbine size since last Jan. so I don't remember which one I
have.

Ed Carver

Ed,
Did you purchase your turbo direct from "Aerocharger" and if so did they
know it
was destined for use with a Rotary engine (no mention of aircraft of
course) ?...........

In doing quick scan of  their site I could find no mention of any Rotary
conversions
using the "Aerocharger"......There was mention of Diesels having used
variable
vane Turbo's but only in gas engines in the last few years because of the
the extra
exhaust heat (200 f +) above a diesel.......Our Rotaries then can produce
another
200 f (+ or -) above that.....Would be interesting to hear what the
"Aerocharger"
have to say on this subject.....IMHO

Kelly Troyer

The exhaust temp on an RX8 side exhaust port engine is 200 F cooler.
Ed is using an RX8 engine as I recall.

Paul Lamar


Kelly,

Actually, if you look @ the military applications listed on the aerocharger
site, they talk about their turbo's being used on rotary powered UAV's
giving
them a 50% increase in power @ 2.5lbs of boost...

-Dan Gorsline

--

The aerocharger is very obviously designed to control heat coming from the
hot gasses that pass through it. They want these things to live long lives.
When you take one apart as I did, it's easy to see. The one truly bizarre
element of it is how close the compressor is to the turbine wheel. This
point alone helps cool the turbine, at the price of heating the intake air.

I plan to inject fuel directly into the compressor inlet, hoping to avoid
the use of an intercooler. The very rapid vaporization of the fuel should
give the compressor a good chill. I'm also going to try to keep the entire
intake system on the intake side of the engine, to avoid long runs of tube
which will tend to bog the whole system down.

When I purchased this thing, I knew it may well melt, in which case, I take
it to the rebuilder, and have the inconel turbine recast. Then make some
solid inconel vanes to replace the originals. I won't be out much if it
breaks.

On the other hand, when I test, it will be under MY intended use loads. I
have no reason to find what it takes to fail it, but only to know if it
will work for me. Given the thin material the vanes are made from, I should
know what I want to know within an hour or so of a test run.

And yes, the rx8 engine will get this unit.

Murry, I did'nt see ya at the last eaa meetn. Hopfully next, we can grind
on this subject for a while.

There should not be any excess boost using this turbo in my install. It is
purely for high altitude flight using the minimum power it takes to
maintain cruise speed. What I think will happen is on take off there will
be no boost, the vanes will be adjusted to prevent it. Then as altitude
increases, vane angle is adjusted to increase turbine speed thereby
maintaining the necessary intake pressure to hold minimum required cruise
power at the chosen altitude.

Realistically idealistic?

Ed Carver