Paul,

What would be the sea level exhaust pressure just before the turbine
inlet in a turbocharged engine?

I'm guessing maybe 18 psi to account for a little bit of back pressure
due to the turbine?

Regards,

Gordon.


I don't have any data on that. I wish I did.

Paul Lamar ...No rotor no motor.


Back pressure is EXTREMELY dependent on exhaust manifold and turbine
configuration.   There is NO typical value!  Mistral has measured full-power
backpressures up to 1.8 bar (23-24 psi) which is unacceptable, resulting in
a significant loss of engine power, and as low as 1.2 bar (17 psi) which
does not optimize turbine efficiency.  By changing manifold configurations
(pulse or constant-pressure system), turbine scroll (single or twin-scroll)
and turbine inlet configuration (A/R ratio), back pressure and turbine
efficiency can be adjusted to the desired compromise.  Believe me, it ain't
trivial.
I recommend highly the following reading:  Diesel Engine Reference Book,
Chapter 2, The Theory of Turbo charging, p. 28-71); it doesn't have to do
with diesel engines only and it is quite comprehensive.

Francois Badoux

It is possible to measure dynamic pressure and not static
pressure. This can be misleading If the pressure port faces
the the rotary engine exhaust port and the flow is coaxial
with the pressure port you will measures dynamic pressure and
not static pressure. Dynamic pressure can be much higher than
static pressure. Also there is an issue with pressure sensor
speed of response. Ideally you want a sensor fast enough to
measure pressure waves.

Paul Lamar ...No rotor no motor.

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