 Posted by
Scorpion
on March 1, 2004
Hi,
here you will learn a few things about Engines
Idea: Turbo Modified
Imagine a centrafugal supercharger, but
with the exhaust impellar half of the turbo instead of the
compressor half (IE take a turbo, throw out the compressor
and attach a pulley with a one way bearing in its place
You'd need to have a wastegate on the
turbine that was open based on some electronics that read
the exhaust pressure and engine rpm. You'll get to a point
when the turbo spools up and the rpm of the turbo pulley and
SC/crank pulley are equal (the oneway bearing isn't slipping
anymore). The belt will try to keep them all turning
together at the same rpm. If the wastegate is left closed
and the exhaust backpressure to climb the engine will either
lose power due to the exhaust back-pressure (and eventually
stall) or the belt would slip, heat up, and break
prematurely. Luckily the electronics for this already exist
as a programmable electronic boost controller... but instead
of opening and closing the wastegate to controlling intake
pressure they'd be controlling exhaust back pressure.
Sort of like Turbo compounding
Idea: Turbocharger with seperate
intake vanes
| I
have extensive experience with turbo charging and I
have to say I've tried every trick I can think of to
lower inlet temps. Most all turbochargers have inlet
and exhaust housings only connected by a shaft and
bearing housings, very little heat actually gets
through this way. There seems to be very little
reduction in inlet temps by wrapping the exhaust
housing in a insulating glass fibre cloth for
example. Heat soaking in to the inlet systen from
the general engine bay has a greater effect on inlet
temps, but becomes irrelevant when a engine is
sucking in a great ammount of cold fresh air and
there is plenty of cooling air flow through the
engine bay. |
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But
a longer shaft, and using two bearings (which would
have less friction than one large set), would help
to reduce heat conducted, and allow the temperature
difference at each end to be greater without placing
added stress on it. The turbine could run hotter,
the compressor could be cooled somehow. So you may
be on to something as yet wholy unbaked infact. |
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Bristolz
and Cedar are right, the heating of inlet air comes
from the compression. (OFTTOMH:) A pressure ratio of
2:1 will heat air at 20 C (67 F) to about 50 C (130
F). A good intercooler will take that down to 30 C,
a air-to-water intercooler can take that lower if
the water is nice n icey for example. A turbocharger
flowing 300 cfm at 15psi takes around 20kw (27hp) of
power to drive the compressor. An exhaust turbine
might be 60% efficient at extracting otherwise
wasted energy from exhaust, thus there's about 8kw
lost in backpressure against the engine (interesting
to note a equivelent supercharger would take that
20kw mechanicly. At 60-70% efficiency around 5kw is
lost as heat which goes into the airflow, and 15kw
goes into accelerating and pressurising the flow. |
Idea: Turbo converted to Jet
engine Supercharger
This idea takes one of these jets that run
off the same fuel supply as the automotive engine and is
mounted anywhere the exhaust gases can escape without
burning the car or road up. Just like the t3-t4 turbo was
created, select a turbo with a large compressor section to
more than power the jet engine itself. On the compressor
outlet, tee the pipe to go back to the burner section and
the automotive intake. Now you have a supercharger that
could potentially provide as much boost as your car can
handle. The compressor and turbine would need to be sized
correctly to provide enough intake pressure for the jet and
your car engine. The only real downfalls are the size of the
system and the extra fuel needed to power the jet, but
wouldn't this be much cooler than just spraying nitrous at
the dragstrip like everyone else?! I think the size can be
made as compact as a typical roots blower that so many
people use for drag racing. Starting the jet usually
requires something to spin the turbine. Routing the car
motor's exhaust through the burner could initally spin the
turbine which may be worth trying.
Idea: Rotary engine side by side
Brief
Forward: One of the great benefits of rotary engines is they
can output incredible power from a very small engine block.
This small size allows carmakers to put the engine in an
optimal position: closer to the car's center. Regular
engines can add extra pistons to increase displacement and
rotary engines can add extra rotors. But by adding extra
rotors the engine block becomes too long and the advantage
of putting weight towards the car's center is lost.
Idea: My idea is to take two twin rotor engine blocks and
put them side by side connected by gears to the flywheel.
This would keep the weight of the engine toward the center
of the car and double the displacement. If two naturally
aspirated Mazda Renesis motors were put side by side, their
power would be just under 500 bhp. Turbocharged, they could
reach over 600 bhp. Again using the Renesis as an example,
this side-by-side engine would weigh less than 400lbs. By
comparison, a Porsche 911 Turbo engine weighs about 450 lbs
and puts out 420bhp.
~*~Remberance:
Just remember that all of these are
ideas, and not from some hightec machanics book alright?
I will add more additions to this
section soon.
-Scorpion
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