View Single Post
Old 04-21-2008, 08:25 AM   #5 (permalink)
Daox
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,203

CM400E - '81 Honda CM400E
90 day: 51.49 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
Mitsubishi
90 day: 56.69 mpg (US)

Daox's Volt - '13 Chevrolet Volt
Thanks: 2,501
Thanked 2,585 Times in 1,553 Posts
A rough texturing on the intake side of the engine is a good thing. It helps create a thicker boundry layer at low intake air velocities. This ends up speeding up the air flowing directly through the center of the intake. We should all know fast flowing intake air is a very good thing as it increases in cylinder turbulence and increase torque. As the mass of air flow increases the boundry layer gets thinner to accomodate the increased volume. At some point this will create a restriction, but for us this should never be a problem since we don't use anywhere near peak horsepower. Polishing the intake will reduce the boundry later and therefore decrease low rpm torque. As LostCause mentioned, this is generally bad for mpg.
__________________
Current project: A better alternator delete
  Reply With Quote