1. Why would the N55 be more sensitive to changes on the cold side? And what do you even mean by that?
2. These types of intakes are only beneficial if your turbo is causing negative pressure in the pre-turbo intake while boosting. To see if this will have an effect, you need to do some manometer testing on the intake along several points. Otherwise, all you're doing is marginally cooling down the intake air and letting more sound out.
This setup is actually pretty stupid. There is no need to add a filter on the end of the secondary intake hose. In fact, you're defeating the purpose of this hose. The hose should ideally face forward in the front of the valence with a scoop to collect air while driving. The idea is to pressurize the airbox with as much air as possible to prevent negative pressure. Adding a filter here is redundant and counter to the original purpose.
Here is a better setup. This was from my Volvo days. Not my pics, but I had a similar setup. Another engineer and I did extensive testing to see gains. Even running a tune with 21 psi of boost, it was less than you would think.
Sophisto Grau / Oyster - Black Nappa, Anthracite Wood
ZAV, ZCV, ZCW, ZDA, ZDH, ZPP, ZP2, ZSP
Mods - M5 Grilles, BMWPedals Black Anodized
Heaven is where the police are British, the cooks are French, the cars are German, the lovers are Italian and it is all organised by the Swiss.
Hell is where the police are German, the cooks are English, the cars are French, the lovers are Swiss, and it is all organised by the Italians
Last edited by Needsdecaf; 09-30-2012 at 08:04 AM.