Quote:
Originally Posted by 19bonestock88
So I was watching YouTube videos about cars (passing time) and I came across a video from Engineering Explained where Jason goes into pros and cons of individual throttle bodies, one of which he said was reduced pumping losses due to not having to pull a vacuum on as large of a “container” with ITBs versus an intake manifold and plenum. Is that to say that properly sized ITBs can increase the efficiency of an engine? Assuming that the rest of the air intake is similar and there’s a plenum above the throttle bodies?
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There's a context to Jason's comment, and he'd have to get into the specificity of an individual engine to flesh that out.
The very existence of a throttle plate introduces an extremely high-drag excrescence within the flow path, regardless of the interior dimensions.
From engine power curves you'll see that an engine's pumping loss fraction reduces and available brake-horsepower output generally increases with load, however, internal friction is increasing as well as energy lost to exhaust, engine oil, cooling system, etc., so pumping loss 'improvement' needs to be compared to concurrent 'degradation' of other engine parameters to reveal the 'net' overall effect.
Jason is kind of a ' boy racer' and what might impress him might work against those with different objectives.
Smart money is on load reduction. Get rid of all you can which requires horsepower to overcome in the first place.
