Yes the turbo itself is a restriction but maybe only for the spool up time? after that it starts to flow exhaust gas pretty well and helps scavenge.
I have a Turbo which has a damaged compressor, this is killing my fuel EF right now and its not balanced, another problem, turbos need to be in 100% working condition for it to help, and the off turbo performance sucks big time.
Why has no manufacturer made a heat recovery system from the heat on the manifold side?
Imagine some kind of closed looped water system getting heated from the exhaust manifold, it could turn an alternator for free?
I don't think I could use it to help the engine directly unless I put steam into the intake
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