Here's some scientific data for you guys.  Somebody may have 
already done this, but I wanted to get numbers for myself.  I 
recently replaced my stock air intake with my own Cold air 
Homebrew ABS tube and K&N filter and removed the rubber flap from 
behind the grill.  I used 3 RTD sensors to get temps from 1.) 
outside, 2.) taped to the new K&N filter, 3.) placed in the 
fender well where the old intake was aimed.  The actual 
temperatures might not be accurate, but relative to each other 
they are.  Here's some average #'s I got, temperatures are in 
Celsius.

		Outside		On K&N	       Fender
Morning before 	14.5		14.6		14.4
start up

Warmed up idle	14.6		45.7		50.4

25mph		14.3		14.7		19.7

60-70mph	14.2		14.5		18.5

What these #'s don't show is that the sensor taped to my K&N 
filter reacted to motion MUCH faster than the one in the fender 
well.  I noticed pulling away from stops that the filter sensor 
dropped to near outside temp almost immediately, while the fender 
sensor took between 30 and 60 seconds.  Hence at steady state 
I've been seeing  4-5C degree (7-9F) cooler temps with my new 
system over the stock intake, and during acceleration up to 30C 
(54F) degree differences.

G-tech shows a 16hp improvement, and my butt dyno agrees.

In my first week I got my best mpg average ever by .5mpg.  This 
was while commuting in traffic while my old best mark was from 
long slow open roads. 

I made my intake out of ABS tubing and shape it Z like.  It 
actually makes two U turns and puts the filter way up in front.

Jay W

I'll get the picture up here as soon as I get it developed.