[KennyP]

Well that sticky mod list is 10 years old... a lot has changed since. Chargepipe
you have to get the one thats specifically made for Z4, Intercooler is same as other n54 bmw-s. Downpipes for stage 2 is same story as chargepipe - Z4 specific product needed. Chargepipe... i think it does not matter what brand you go. In the end it is just a pipe. Maybe stay away from noname china ebay pipes. VRSF is ok i think.You can get everything from them(intercooler, chargepipe, downpipes with a single order). Just choose what diverter valves or blowoff you are going with and get the pipe that works with these. With single big blowoffs like hks and TIAL you must know this: they need a bigger diameter vacuum line to work properly. You cant use oem nipple on the intake manifold for that... You can go ghetto and drill and fit a new nipple or there were some adapters you could buy and fit between somewhere to get the bigger feed nipple without drilling and so on. If you want to use oem vacuum line and feed from intake manifold you have to get smaller dual diverter valves/ blowoffs like turbosmart or forged. Personally i have a parts list made up and have turbosmarts on that build/wishlist. Turbosmarts because they are easier to get in the EU.