Dyno of both with the same inner diameter (ID) tubes on the same motor.

"When the diameters of the intakes are identical, there is virtually no difference between the 2 intakes from 5700 rpm to the redline (upper powerband) and only a difference at the infamous "AEM hump" in the midrange."


Also shown is the volumetric efficiency of different lengths of intake tubes.
"A longer tube creates faster air flow compared to a short tube (i.e. more pressure differential from the opening to the TB end) and peak volumetric efficiency will occur at an earlier (i.e. lower) rpm. This is why a longer CAI has an advantage in the midrange over a short ram, regardless of intake temperature differences."

Hmm... interesting. AEM CAI water bypass valve. "It is noteworthy that the bypass valve lowers power by 2-3whp across the entire rpm range but you can sleep at night. "

AEM vs. Injen.... "Injen was formed by an ex-AEM employee and it's 2 piece CAI is essentially an AEM design with the ability to convert to a short ram. They now have a 1 piece CAI that looks identical to the AEM."


Quotes taken from AutomotiveTech.org

 

I have always said and still stand by it that the water bypass valve sucks. I saw an AEM sposered test on it where they made custom intake piping to go outside tha car to a fish tank on the ground full of water and that thing must have filled up like 3 ft with water before the bypass opened and it only works when fully submerged. So if your going to hit a puddle make sure you hit one at least a foot deep, if not deeper.

 

Oh yeah, one other thing I forgot to mention in there was that a test of intake temperatures at speed (while moving) were virtually identical between the SRI and the CAI. So it appears that the intake charge temp is negligible as soon as you start moving and the famous AEM hump is caused by the length of the tubing, not the "cooler" incoming air. So basically you could add a length of tube to your SRI and get a bump in mid-range.