Quote:
Originally Posted by cRiPpLe_rOoStEr
The original Miller cycle uses a supercharger. I might admit that I'd be quite worried about the discompression at the start of the expansion stroke decreasing the boost with a turbocharger...
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Stop me if I am not using proper wording.
Induction
Compression
(Explosion)
Expansion
Exhaust
Miller (/Atkinson) is about lowering the duration of compression to maximise the effect of expansion.
It is oftenly done by increasing induction above what is required.
So, at the start of the compression stroke, there could be a gulp back of air that could stop the turbine from spinning resulting in fatigue failure of it just as what could be seen when closing the throttle.
There is a cure to this throttling issue, namely recirculation valve, but you are right, it could be not suitable at a high rate of use.
Maybe, the only way around it is to use a phaser on the inlet to run in atkinson up to a specific rpm and then normal phasing when power is requested.
Or maybe with low boosting and longer inlet tract ...
Anyway, sorry about the thread hijacking ...