What JWILL and 20VVILLIAN said, plus what is on site is not cold air intake. It suck with his cone hot air from engine compartment, plus low air pressure (i.e. big pressure drop).
Tests carried out by CB5 member Geri (also Moderator on
www.passat3B.de)
Copy of his mail after tests:
quote
"Yes, BMC is realy fantastic! As I said, never had such good amounts on
MAF. You have to know that with the OEM Intake you wont have more then 145-150mg/H at high REVs (measured at two differnet OEM V6s). With the K&N Kone by best ever was a 164mg/H, now I can reach this amount in even low REVs when accelerating. By best amount now is 174mg/H - and this with my old MAF Sensor (the newer one is still on K&N Cone, will change soon). And Airintake-temperature is nearly like outside Temp, only 1 or 2 Deg higher. With OEM Intake you will have about 5 Deg higher Temp than outside. With K&N(open cone filter-simmilar to Evo) the Temp was at high Revs about 15 Deg higher than outside. I was told that a decrease of 10 Deg results in a plus of 3% more Power.....*ggg* In this case OEM Intake is not sooo bad."
quote
BTW, BMC CDA and Evo CAI are t the moment most expensive CAI kits on market. And IMHO, BMC CDA is at the moment only(beside RAID) true CAI
http://www.bmcairfilters.com/infoCDA.asp