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Old 09-28-2018, 08:31 PM   #11
Who's askin'?
 
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Join Date: Mar 2018
Location: Utah
Posts: 2,448
Quote:
Originally Posted by Timothydunn88 View Post
.....My only question for the fuel economy part its asks for alot of information and the only thing I dont know and I cant find is the volumetric efficiency. What is that?
I can tell you what volumetric efficiency is, but I cannot tell you what the measurement is for your car.
Volumetric efficiency is a measurement of the air-fuel mixture mass that is inducted into the cylinder, compared to the actual swept volume of the piston / cylinder. It is expressed as a ratio or percentage.
For instance; if at the bottom of the induction stroke, your air fuel mass in the cylinder is equal to the same air fuel mass that cylinder volume would occupy in the intake manifold, then you are 100%. Most internal combustion engines that are not special purpose-built race motors run around 85 to 90%. Meaning that the mass in the cylinder is only about 90% of what mass the same volume would contain in the intake.
Careful tuning, multiple valves, porting of heads & bowls, etc, can improve this, even up to around 130%. This is quite uncommon for a N/A car.
Forced induction motors can approach 300%.

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