View Single Post
Old 03-27-2011, 07:26 PM   #59
serialk11r
Senior Member
 
Join Date: Mar 2011
Drives: '06 AM V8V Coupe
Location: United States of America
Posts: 5,279
Thanks: 285
Thanked 1,075 Times in 759 Posts
Mentioned: 13 Post(s)
Tagged: 1 Thread(s)
Garage
Oh I just remembered, with Valvematic since valve lift (restriction basically) and duration are correlated, mods to increase intake flow will actually benefit fuel economy as well. Regular engines need a throttle to restrict air, so restrictive intake doesn't hurt economy since the car needs to run at partial throttle anyways. The efficiency penalty from sucking more air in exceeds the efficiency benefit from less pumping loss at around 80% max. torque or so on throttled engines I think. Variable valve lift will lower this.

On fuel economy websites they do warm air intakes, basically trying to suck air around the exhaust to heat it up, to reduce the air's density and let the throttle open up more, reducing pumping loss. Variable lift could change this too, making cold air intake have less throttling loss at part load and since it's more thermodynamically efficient, possibly have increased fuel economy from cold air intake.

Not that people care that much lol.
serialk11r is offline   Reply With Quote