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Old 12-26-2012, 01:07 PM   #36
RayPooley
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Join Date: Jul 2012
Location: Liverpool
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My Ride: 320i SE Coupe
Quote:
Originally Posted by bimmerfan08 View Post
Originally Posted by E46330iguy View Post
Because It wouldnt save you fuel on a 40 hp Engine, A turbo atomizes the air to help it burn better. Larger engines tend to be less efficent thus why they make a difference is my understanding

Nothing to do with atomization of fuel. Normally aspirated engines suck air into the pistons during the intake stroke. Therefore the air inside the piston at the start of the compression stroke is typically less than atmospheric pressure. A turbo charger pumps compressed air into the piston during the intake stroke. Therefore the air inside the cylinder is typically above atmospheric pressure at the start of the compression stroke. The net effect is more air inside the cylinder at the start of the compression stroke. This achieves a higher compression ratio equivalent to a normally aspirated engine with larger cylinders but without the additional piston mass and inertia of the larger engine. Net effect is higher performance which should not be confused with higher efficiency. Of course, turbo charging does require an appropriate adjustment in fuel delivery in order to maintain the optimum 14.7 : 1 air to fuel ratio.

Last edited by RayPooley; 12-26-2012 at 01:07 PM.
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