I see where Audi is introducing the 2011 A1 e-tron electric car with a 254cc
rotary engine to power a 15kw generator.  Does anyone have any info on this
engine?

Mike Perry
Long Ez
N981MP
Mazda 13B

If true it is probably the SuperTech engine

http://www.wankelsupertec.de/

Where did you see the info Mike?

Paul Lamar
--

   March issue of Popular Mechanics, page 36.

   Mike Perry

   Here is the web site.

   http://tinyurl.com/5t5sozb

   That is a tiny engine. My guess is 25 HP.

"The Wankel weighs in at just 154 lbs and displaces just 254 cc of volume in
its single rotor.  The whole unit is small enough to sit below the cargo
floor of the A1.  Running at a constant 5,000 rpm, the rotary motor can
extend the A1 e-tron's range to 130 miles.  Why not longer?  The fuel tank
holds only 3.17 gallons.  With the Wankel running, Audi says the A1 e-tron
will return about 124 miles per gallon U.S."

   That weight must be engine and generator.


   Paul Lamar

I had a meeting with AVL two weeks ago and they proudly mentioned they did
the integration of their Rotary engine into the Audi A1. More versions and
different power ratings are apparently in the pipeline.

There you got your answer.
Randolph in Paris

Pardon my ignorance Randolph but who is AVL?
Is it this company?
https://www.avl.com/ic-engine

I had no idea they had a rotary engine.

Paul Lamar


Hi,  if you follow the AVL link to their 2010 magazine there is a picture
and a little info on their rotary/generator range extender.

Murry I. Rozansky

Thanks for the tip Murry.

https://www.avl.com/media-publications

I can't tell much about the intake and exhaust system but it looks like one
could saw off the generator and use just the engine. It has an interesting
shape for the depression in the rotor. I have seen other similar shapes in
other Wankel's and it seems to be a promising area for development.

The key is rotor cooling. It does not look like a charged cooled rotor so
that is promising. It appears to be an oil cooled rotor.

Paul Lamar

-----------------------------------------------------------
With a bit of gimp enhancement I can see a peripheral port. Could be intake
or it could be exhaust. The toothed wheel on the right looks like ignition
and tach trigger. From the gap in the toothed wheel we are roughly looking
at the spark area.

Paul Lamar

Paul,It appears to have aluminum side housings with an iron wear surface
sandwich construction.  If available for purchase I would definitely leave
the generator housing for aircraft use. It is water cooled so putting the
PSRU planetary and oil in the bell housing would provide cooling for the
gear train. That would allow gear lube to be used for the PSRU.  It appears
to have enough cooling volume  that turbo charging might be possible.Without
the generator some type of recoil starter might be incorporated to get it
running like on an ultralight.

george grimes


As a car this concept 3D jpg will work much better. Same small rotary
mounted on the front of a two rotor for cruise. The fact is most cars only
require 25 HP or less to move up to 60 MPH.

The trouble with electric cars and range extenders is once you are out of
battery you have a 2500 pound to 3000 pound car powered by a 25 HP motor.
Hill climbing or acceleration is no longer available.
They are not general purpose cars. Fine if you can afford 2 or more cars.

With my scheme you don't give up hill climbing and acceleration. The two
rotor is always ready, willing and able to climb hills rapidly and
accelerate well.

No batteries. No extra weight for batteries. Cheaper! No powerful heavy
electric motors and expensive controllers. It is all done with a one way
clutch.

http://www.rotaryeng.net/RX8-TC-eng3.html

Paul Lamar



Unless, of course, you use the battery as a buffer, as every plug-in hybrid
does. That still won't let you charge up a long upgrade, but it will easily
handle any normal acceleration spurts or short upgrades.

Csaba Csere

True. I suspect the high Audi MPG numbers are optimized for
the EPA driving cycle which is modest indeed.

You can still creep away from the stop lights on the 25 HP RX8 two and a
quarter rotor engine alone :) It all depends on how you want to drive. Did
you see that BBC Top Gear segment where a BMW got better MPG following a
Prius around a road coarse?

Paul Lamar

Paul,

I didn't see that Top Gear segment and will look for it.

By the way, the current EPA cycles, which were updated three or four years
ago, are actually tougher and quite realistic for normal driving. Driving
briskly, I regularly get higher mileage than the current EPA estimates.

Csaba


It is interesting to speculate on the performance of the
Audi. I think they are claiming 124 MPG. Now I don't know how
they do that. If the rotary was running full power at 25 HP it
would be burning 12.5 pounds of fuel an hour assuming a BSFC
of .50. I don't see anything about that rotary that would
convince me otherwise.

12.5 pounds of fuel an hour is right at 2 gallons an hour.
At 60 MPH that is 30 MPG. NOT 124 MPG. At 80 MPH it is 40 MPG
if it in fact it will do 80 MPH on only 25 HP.

I am being very generous here and assuming the drive line efficiency
is 100%. The real drive line efficiency is closer to 80%. Generator
90% times motors 90% equals 81%. Same for a diesel electric
locomotive. Truck mechanical drive lines are actually more
efficient however rolling resistance is higher. I digress.

Obviously they are playing tricks with the calculations. They are
not including the electricity used to charge the battery and are
limiting the time the vehicle is running solely on the power of
the 25 HP rotary. The real MPG depends on the BTU's consumed to
generate the electricity needed to initially charge the battery. Not
an efficient process due to multiple stages of voltage conversion,
transmission line losses and primary power plant efficiency.
In France or Japan one does not care about power plant efficiency
as it mostly done with nuclear power. Just more nuclear waste
is generated.

The Water Melon would then say "Yes but we are going to generate
the power with wind and photo voltaic". I am still waiting.
They are dishonestly abusing the excuse of the environment to
gain absolute power over the individual to form a mythical Utopian
world.

Shades of our current devious government. Lying or misleading at best.

Paul Lamar