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Turbocharger power input (consumption)
langwadt:
--- Quote from: unknownparticle on March 25, 2020, 05:05:15 pm ---Just another thought on the power required by a turbo to provide useful boost pressure. Say you have a NA engine producing 200 BHP, for the sake of discussion a 2Ltr 4 cylinder unit, and you want 300 BHP using a turbo. So, ignoring all the other stuff needed to accomplish this, and all the relevant efficiencies, losses etc etc. In simple terms, power in = power out, so to produce that additional 100 BHP the turbo needs at least 100 BHP from the exhaust gas off the engine to do that. In practice, due to losses, efficiency, etc, etc, it needs more than that. So, more than 75 KW of energy, regardless of the turbo used. Unless I'm getting something very wrong!
--- End quote ---
yes you got it wrong, the turbo doesn't need 100hp to add 100hp, it needs the power required to add enough air to burn ~300hp more worth of fuel
Mazo:
--- Quote from: unknownparticle on March 25, 2020, 05:05:15 pm ---Just another thought on the power required by a turbo to provide useful boost pressure. Say you have a NA engine producing 200 BHP, for the sake of discussion a 2Ltr 4 cylinder unit, and you want 300 BHP using a turbo. So, ignoring all the other stuff needed to accomplish this, and all the relevant efficiencies, losses etc etc. In simple terms, power in = power out, so to produce that additional 100 BHP the turbo needs at least 100 BHP from the exhaust gas off the engine to do that. In practice, due to losses, efficiency, etc, etc, it needs more than that. So, more than 75 KW of energy, regardless of the turbo used. Unless I'm getting something very wrong!
--- End quote ---
To get more power you need more air/fuel mixture to burn.The turbo gets you more air than possible with NA and the FUEL gets you the energy input.Following your line of reasoning a supercharger(driven by the engine by a belt in most cases) is a completely useless device as it will take 100hp to "give"100hp,and yet superchargers exist and are useful.As langwadt says it seems you are getting it wrong.
By the way I once made a rough calculation on the power needed for a pretty small boost of 0.3bar on a 1.6L engine and the number I got was around the 5kW mark of electrical power needed.Very difficult to supply on 12V and by a standard alternator.
firewalker:
--- Quote from: Mazo on March 25, 2020, 05:22:39 pm ---Just another thought on the power required by a turbo to provide useful boost pressure. Say you have a NA engine producing 200 BHP, for the
By the way I once made a rough calculation on the power needed for a pretty small boost of 0.3bar on a 1.6L engine and the number I got was around the 5kW mark of electrical power needed.Very difficult to supply on 12V and by a standard alternator.
--- End quote ---
Did you just calculated the mass and the speed of air per second? I did that and my result same as yours.
Alexander.
joeqsmith:
Because it was brought up:
https://itstillruns.com/honda-gx140-specifications-7661089.html
About 1000HP to turn the blower (supercharger) on a T/F car. One sport you need to be there, in person to appreciate what a 10KHP car does.
--- Quote from: unknownparticle on March 25, 2020, 04:57:14 pm ---Had to find that guys name!! Nick Mann, heres his website with full details :-
https://raceenginedesign.co.uk/the-manic-beattie/
Really interesting if you're a petrol head.
--- End quote ---
Thanks for the link. I've never seen or heard of this. A good read and a couple of nice videos on YT.
joeqsmith:
First Google hit, finds your question and even mentions the T25. Gotta love these modern search engines. :-DD
https://www.theturboforums.com/threads/how-much-power-engery-to-spool-a-turbocharger.343610/
I'm a member on this forum but not very active but it is a very good source of information.
https://www.theturboforums.com/threads/some-efi-hacking.373927/
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