Kirby:
Guess you haven’t see the twin-charged Lotus:
Very cool car, but my, there’s a lot going on.
Nope. Still rubbing my eyes and re-reading. Quite the creation.
Some designs for variable compression are varied by a second con rod that can be moved in or out to vary the stroke!!!
Clever…but adding yet more complexity.
We are essentially flogging a dead horse with the internal combustion engine.
We only use 1/4 of the energy in the fuel…and we won’t get it much higher because of some fundamental rules.
We need to find a better way of moving about.
Star Trek had a good idea…“Beam me up Scotty…ok ok…now beam up my damn clothes!!!”
Heh heh…molecular transmogrification .
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Is this Volvo motor similar to the mk5 Golf 1.4 litre TSI (turbo/supercharged) motor launched 12 years ago at the Frankfurt motor show?
Trev
Is this Volvo motor similar to the mk5 Golf 1.4 litre TSI
(turbo/supercharged) motor launched 12 years ago at the Frankfurt
motor show? Trev
The article mentioned that VW had introduced one some time back, but it
had not made it to the US market. They also commented that the Volvo
incarnation was far more refined.
Dumb question for you guys: Am I correct in understanding that the
turbocharger blows THROUGH the Rootes blower? Like, when the
supercharger’s drive clutch is disengaged, it “freewheels” to allow airflow
through it? On cars with a Rootes supercharger only, is the supercharger
ever disengaged for any reason? And does the engine just suck air right
through the blower?
– Kirbert
you got it right , on Rootes blower engines the blower is always engaged, but POWER to run it is reduced by estimates of 75%.
the turbo far over runs the blower rotors, because it can deliver much more air flow.
the rotors do just freewheel, not the best way to do things, but it does work without redesigning a completely different engine!
ALAH, Detroit 2 stroke diesels, turbocharged and rootes scavanger blower!, others cant think of at moment.
…on Rootes blower engines the blower is always
engaged, but POWER to run it is reduced by estimates of 75%.the turbo far over runs the blower rotors, because it can deliver much
more air flow.
I guess I’m not understanding why the Rootes blower doesn’t take the
pressurized output of the turbo and compress it FURTHER. That would
seem to INCREASE the power to run the blower, as it’s compressing a
charge that is denser to begin with.
– Kirbert
logic and reality two different things!
rootes by there very design, are limited as RPM goes up,they become an obstruction in air flow, they pump more air at idle than at 5000rpm by percentage, and the method of compression heats the air above usefulness, new issues show up,detonation, friction drag, and rotors start to cavitate.
a proper turbo at 1/4 the weight/size can pump more air than most rootes blowers!
now lets not get into top fuel Nitro type engineering!!LOL. they use the blower as a pump to push nitro/air into the cylinders,oxygen is produced as the nitro burns! ( kinda kool USA hotrod idea, they did it because they didnt know they COULDN’T.)
also some modern belt drive centrifugal superchargers, have made amazing results, and show some potential! along with the Screw type blowers, supposedly better than Rootes, for rpm potential!
puting all that two types of superchargers together.
and the design/engineering to make it all work for any useful length of time is questionable!
modern factory turbo cars are just about perfect,at this time! NO lag.
one that comes to mind , my inlaw had a BMW MINI, that was blower type, good performance.
he sold it for a new Mini with turbo ,much better car and faster!
factory had to have good reason for change?
i have seen some of the rootes engines use a BYPASS valve to allow more air from a turbo to get to inlet manifold!
Am I correct in understanding that the
turbocharger blows THROUGH the Rootes blower? Like, when the
supercharger’s drive clutch is disengaged, it “freewheels” to allow airflow
through it?
Kirby
On my e55amg the supercharger free wheels in the inlet flow on an electric clutch. I think the solution would be to have the turbo in parallel with the supercharger and sensors to detect which can deliver the highest pressure flow stream. The supercharger will be dominant at low speeds and when the turbo pressure exceeds the blower pressure suitable valving switches to the turbo and disconnects the supercharger clutch to remove the direct parasitic losses you still have the pressure drop from spinning the supercharger…but in the scheme of things it probably doesn’t matter that much because the turbo is on full boost ramming combustibles into the engine… it also means the blower is instantly available because it is spinning at a few percent below synchronous speed and the shock on the blower drive system is minimal. The rootes blowers are relatively inefficient relative to the twin screw lysholm type which compress the gases as part of the geometry rather than the rootes which just moves air and requires throttling to achieve pressure.
Be interesting to know how it is ACTUALLY done…
Regards
Matt
Nitrous is also a multiplier: WHEN your engine goes supernova, the use of nitrous actually CREATES more parts than you started with.
Neat, huh?
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