Re: the Navarro Six, O-ring questions

[adh@xxxxxxxxxxxxxxxxx (Sandwich Maker)]

" From: Tom Jennings <tomj@xxxxxxx>
" 
" 
" I made a spreadsheet with some of the basic turbo calcs. With the
" TE06 and motor at 6000 rpm, one turbo would produce 20psi and
" r=2.4. A second TE06 at r=2.4 with input at 20psig makes 45psig
" output.

wild guess: 'r' is pressure ratio, right?

then, using a for atmospheric pressure and b for boost,
( a * r ) - a = b
right?

if so, r=2.4 gives b=20, and r=4.1 gives b=45, pretty closely.

" With those numbers, the nomograph 650 - 700 hp looks about right.
" 
" If I 'play' the calcs and assume a turbo can do atmospheric to
" 45psi in one step (for comparison purposes only) it would be
" r=4.1.
" 
" It seems very likely that two turbos in series probably is less
" than twice as efficient (since obviously a lot of energy is taken
" out of the exhaust gas by the first turbo) a total r=4.1, far less
" than the theoretical r=5.76, seems ball-park reasonable.

if my equation above is right, then for two equal-step turbos in
series the equation would be
( a * r * r ) - a = b
and r=2.4 gives b=70!  r=2.0 gives b=44.

single stage compressors get less efficient as pressure ratio climbs,
so at some point two low-compression stages are -more- efficient than
a single high-compression stage.  i believe it's due to heating of the
charge, which destroys density.

" But 50 psi plus or minus has got to be the number, to get 700 hp
" from 182 ci.

just fyi and fwiw, two turbos of r=2.1 give b=50 on the nose.

also, you wouldn't want two turbos of equal size, which is what i
presume 'te06' suggests.  since the first one has already compressed
the input charge by ~50%, the second should be about half the size.
one t06, one t04?
--
you can improve turbo efficiency by spraying water [or alcohol, or a
mix] into the eye of the compressor.  it soaks up the heat of
compression by evaporating right as the work is being done.

going to run intercoolers?
________________________________________________________________________
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen

adh@xxxxxxxxxxxxxxxxx                       and think what none thought