Why turbo normalizer?

This started on a Mooney list. I cannot for the life of me (and an
engineering degree) figure out why a turbo normalizer would be any
easier on an engine than a regular turbo. Is this just marketing crap
from the turbo normalizer people? Turbo'd engines cost more to run
because of the increased stress on the cylinders, rings, etc do to the
pressure. Running an engine at 30MP when outside is 20" is just as much
pressure difference as running at 40MP when outside is 30". It seems
like the turbo norm crowd is trying to confuse people. Unless the
entire engine was pressurized to 30", you should expect turbo style
stressed on your engine when running 30" when outside is 20". This is
*much* different than running 30" when outside is 30" (down low). Am I
missing something?

-Robert

I always thought that "turbo-normalized" is just another way of saying
"turbo-charged?" I. e. that they're both the same?


--
Michael Nouak
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"Robert M. Gary" schrieb im Newsbeitrag
oups.com...
This started on a Mooney list. I cannot for the life of me (and an
engineering degree) figure out why a turbo normalizer would be any
easier on an engine than a regular turbo. Is this just marketing crap
from the turbo normalizer people? Turbo'd engines cost more to run
because of the increased stress on the cylinders, rings, etc do to the
pressure. Running an engine at 30MP when outside is 20" is just as much
pressure difference as running at 40MP when outside is 30". It seems
like the turbo norm crowd is trying to confuse people. Unless the
entire engine was pressurized to 30", you should expect turbo style
stressed on your engine when running 30" when outside is 20". This is
*much* different than running 30" when outside is 30" (down low). Am I
missing something?

-Robert

I cannot for the life of me (and an
engineering degree) figure out why a turbo normalizer would be any
easier on an engine than a regular turbo. [...]
Running an engine at 30MP when outside is 20" is just as much
pressure difference as running at 40MP when outside is 30".

I don't do turbo (I like to fly low anyway) but my understanding from
ground school is that it is not the pressure -difference- that makes the
difference. It is the pressure for which the engine was designed.

A turbo normalizer merely makes up the difference between where you are
(high) and sea level, so the engine can develop as much horsepower at
altitude as it could at sea level. The engine was =designed= for that
much horsepower, so all is well.

A turbo supercharger pumps more air into the engine than even sea level
pressure would give it, allowing more fuel to be burned, and more power
to be generated, than the engine was originally designed for. This is
hard on the engine.

Or something like that.

Jose
--
Money: what you need when you run out of brains.
for Email, make the obvious change in the address.

"Robert M. Gary" wrote in message
oups.com...
This started on a Mooney list. I cannot for the life of me (and an
engineering degree) figure out why a turbo normalizer would be any
easier on an engine than a regular turbo. Is this just marketing crap
from the turbo normalizer people? Turbo'd engines cost more to run
because of the increased stress on the cylinders, rings, etc do to the
pressure. Running an engine at 30MP when outside is 20" is just as much
pressure difference as running at 40MP when outside is 30".

It's not the 10" difference that matters. It's the new number after it's
been multiplied to take into account compression and combustion pressures.
Compression alone multiplies the number by about 8 (typically), but because
the turbo is packing so much more air and fuel into the cylinder, the
combustion pressures go up at a much greater rate.

After considering the multiplicative effects, the ambient baseline is
irrelevant. It's the absolute pressure that's the big deal, and it's higher
when you turbocharge.

Of course, for some engines, even a 30" MP while the engine is running could
be an issue, at least for long periods of time. There's a reason some
engines are limited to full power for some period of time (5 minutes, for
example). Comparing turbo-normalization and turbocharging above sea level
pressure only makes sense when you are comparing apples-to-apples (ie same
basic engine).

It seems like the turbo norm crowd is trying to confuse people.

What statement by the "turbo norm crowd" do you find confusing?

Unless the
entire engine was pressurized to 30", you should expect turbo style
stressed on your engine when running 30" when outside is 20".

Wrong. See above.

This is
*much* different than running 30" when outside is 30" (down low). Am I
missing something?

It appears that what you are missing is that the ambient air pressure
doesn't really matter, not in this context.

Now, all that said, it's not entirely true that turbonormalization is no
harder on an engine than running the engine at sea level. At altitude, the
ambient air may be cooler, but there's a lot less of it for cooling. In
addition, compresing the induction air heats it up. So even a
turbonormalized engine may run hotter than a normally aspirated engine would
at the same MP.

But it is true that turbo-normalization doesn't stress a given engine as
much as turbo-charging above sea level pressure.

Pete

"Michael Nouak" wrote in message
...
I always thought that "turbo-normalized" is just another way of saying
"turbo-charged?" I. e. that they're both the same?

Turbo-normalized always means turbo-charged. Turbo-charged does not always
mean turbo-normalized.

Turbo-normalized means that the induction pressure is limited to normal sea
level pressure (30"). Many turbocharged installations raise induction
pressure to higher than this, and thus are not "turbo-normalized".

Pete

That clears it up, thanks

Mike

"Peter Duniho" schrieb im Newsbeitrag
...
"Michael Nouak" wrote in message
...
I always thought that "turbo-normalized" is just another way of saying
"turbo-charged?" I. e. that they're both the same?

Turbo-normalized always means turbo-charged. Turbo-charged does not
always mean turbo-normalized.

Turbo-normalized means that the induction pressure is limited to normal
sea level pressure (30"). Many turbocharged installations raise induction
pressure to higher than this, and thus are not "turbo-normalized".

Pete

Robert M. Gary wrote:

Am I missing something?

-Robert

The intake manifold pressure to ambient pressure differential is
probably the least important value in the equations you are discussing.

This comes down to the total generated power of the powerplant. The
engine is rated to make "X" horsepower. Lets say "200". At sea level. On
a standard day. As you climb, the higher pressure altitude (and
presumably higher density altitude) results in not being able to develop
that full 200 hp.

Pressurizing the plenum with a turbocharger or supercharger allows that
power to be generated at higher altitude.. but you already knew that. If
you go boosting the engine to 2-3 ATM you can make a BUTTLOAD of power
but the reliability will be in the toilet. WWII piston fighters and
bombers used to run MAP's in the 40-50-60" range.. but long term
reliability wasn't the primary issue for them.

Turbo-normalizing is a limited form of turbocharging that results in the
power being generated being limited to about what a normally aspirated
engine makes at sea level. The Crankshaft, prop, pistons, rods and other
"stuff" in the engine is subjected to no more stress than the engine
would be at sea level (with some limitations - the turbocharged air is
warmer, so there is a power loss and potential for detonation.. the air
at altitude for cooling is less dense, so its cooling ability across
intercoolers and cylinders is lessened... you get the drift).

Heavily turbocharged engines dont have short TBO's because of inlet
plenum failure due to air pressure fatigue.. they have short TBO's (when
operated improperly) due to cracked cranks, overheated cylinders,
excessive wear type stuff.

So.. no.. its not a marketing gimmick. Turbonormalizing an engine isnt
as big a deal, because the engine is not intended to exceed its original
"normally aspirated" sea level power rating.

Make sense?
Dave

"Dave S" wrote in message
k.net...
[...]
So.. no.. its not a marketing gimmick. Turbonormalizing an engine isnt as
big a deal, because the engine is not intended to exceed its original
"normally aspirated" sea level power rating.

Thanks Dave...you explained it much better than I did. I left out a lot
of details that, in hindsight, would have really helped get the point
across.

Peter Duniho wrote:

"Dave S" wrote in message
k.net...

[...]
So.. no.. its not a marketing gimmick. Turbonormalizing an engine isnt as
big a deal, because the engine is not intended to exceed its original
"normally aspirated" sea level power rating.


Thanks Dave...you explained it much better than I did. I left out a lot
of details that, in hindsight, would have really helped get the point
across.



If anyone wants even further info on the matter, I would say go to Avweb
and look up John Deakin's columns on "Those Fire Breathing Turbo's".
www.avweb.com , link to columns, and his stuff is in there.

Dave

"Dave S" wrote in message
k.net...


Peter Duniho wrote:

"Dave S" wrote in message
k.net...

[...]
So.. no.. its not a marketing gimmick. Turbonormalizing an engine isnt
as
big a deal, because the engine is not intended to exceed its original
"normally aspirated" sea level power rating.


Thanks Dave...you explained it much better than I did. I left out a
lot
of details that, in hindsight, would have really helped get the point
across.



If anyone wants even further info on the matter, I would say go to Avweb
and look up John Deakin's columns on "Those Fire Breathing Turbo's".
www.avweb.com , link to columns, and his stuff is in there.

http://www.avweb.com/news/columns/182146-1.html