Turbo performance vs non-turbo

Matt Barrow wrote:

A turbo'ed engine is built more "solidly" than a normally aspirated.

This would not be true of an engine which has had a turbo-charger added, would
it? I see, for example, that the Commander that AOPA is renovating this year
just had a turbo added via STC.

George Patterson
Drink is the curse of the land. It makes you quarrel with your neighbor.
It makes you shoot at your landlord. And it makes you miss him.

"George Patterson" wrote in message
news:ZQl0f.5376$MO2.3022@trndny09...
Matt Barrow wrote:

A turbo'ed engine is built more "solidly" than a normally aspirated.

This would not be true of an engine which has had a turbo-charger added,
would it?

It would be true for a factory turbo, but not an STC add-on I imagine.

The IO-520 in the Beech F33's is different internally from the TSIO-520 in
the B36-TC. Unfortuantely, it was not ideal, so the best upgrade is the
TNIO-550, especially ones from such engine shops as Superior Airparts or
Western Skyways.

I see, for example, that the Commander that AOPA is renovating this year
just had a turbo added via STC.

I believe that's a Turbo Alley turbonormalizer, not a Turbo "supercharger".
If not, I suspect the STC might require some "beefing up" of certain parts.


--
Matt

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Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

Matt Barrow wrote:

I believe that's a Turbo Alley turbonormalizer, not a Turbo "supercharger".
If not, I suspect the STC might require some "beefing up" of certain parts.

According to the article, it's a RCM turbonormalization package which contains a
turbocharger. The turbocharger is made by Kelly Aerospace. They say they have
over 1600 hours on one Commander with it.

This unit keeps the manifold pressure at or below 28 PSI. I take it you were
describing systems that do not have this limitation.

George Patterson
Drink is the curse of the land. It makes you quarrel with your neighbor.
It makes you shoot at your landlord. And it makes you miss him.

"George Patterson" wrote in message
newsUm0f.35172$wb3.22707@trndny03...
Matt Barrow wrote:

I believe that's a Turbo Alley turbonormalizer, not a Turbo
"supercharger". If not, I suspect the STC might require some "beefing up"
of certain parts.

According to the article, it's a RCM turbonormalization package which
contains a turbocharger.

That sounds like being "sorta pregnant". A TN system has a TC, but the
popoff keeps it from running beyonf normal sea level pressure internally.


The turbocharger is made by Kelly Aerospace. They say they have over 1600
hours on one Commander with it.

This unit keeps the manifold pressure at or below 28 PSI.

That's about typical for a TN system. Mine keeps MP at or below 31.5 inches.

I take it you were describing systems that do not have this limitation.

A TN system will been a TC Lite :~)


--
Matt

---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

Right. A turbonormalized engine never sees any more pressure than one
that is normally aspirated - it just sees it up to a high altitude.
Cooling (at high altitudes) may be an issue, but not cylinder pressure.

jmk wrote:
: Right. A turbonormalized engine never sees any more pressure than one
: that is normally aspirated - it just sees it up to a high altitude.
: Cooling (at high altitudes) may be an issue, but not cylinder pressure.

Actually, technically speaking, running the same MP at higher altitudes will
produce a little more power than at lower altitudes. The lower ambient pressure
reduces backpressure on the exhaust, so there's more scavanging and a bigger intake
air/fuel charge for the same MP.

I saw that in the performance specs on a friend's normally-aspirated
PA-24-250. Something like equal power is between 1-2" different MP at 12000' vs. sea
level (RPM constant). I don't remember the exact numbers, but that's in the ballpark.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

wrote in message
...
jmk wrote:
: Right. A turbonormalized engine never sees any more pressure than one
: that is normally aspirated - it just sees it up to a high altitude.
: Cooling (at high altitudes) may be an issue, but not cylinder pressure.

Actually, technically speaking, running the same MP at higher altitudes
will
produce a little more power than at lower altitudes. The lower ambient
pressure
reduces backpressure on the exhaust, so there's more scavanging and a
bigger intake
air/fuel charge for the same MP.

I saw that in the performance specs on a friend's normally-aspirated
PA-24-250. Something like equal power is between 1-2" different MP at
12000' vs. sea
level (RPM constant). I don't remember the exact numbers, but that's in
the ballpark.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************


It doesn't work that way with a turbocharged engine since the ingested air
is heated by compression.

Mike
MU-2

Mike Rapoport wrote:

: It doesn't work that way with a turbocharged engine since the ingested air
: is heated by compression.

I would argue that it still works that way. In addition, however, the heating
of the intake air reduces the effective mass on the intake charge. Whether one or the
other dominates or they cancel each other out depends on lots of factors... in
particular an intercooler.

I'm not being argumentative... just sharing info that I'd never thought of
before. It doesn't make a huge difference, but it does make a difference. Running
24/24 doesn't *always* make the same power or burn the same fuel. Altitude and
mixture both have 10-20% adjustment fudge factors in there.... throw in a turbo with
heating and there's another 10-20% in the mix as well.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************