With so much hyperbole (and lies) flying about with regards to tuning etc, during my search for information about things to do with the crossflow install I’ve come across a couple of sites that have provided a welcome pinch of salt:
http://www.pumaracing.co.uk/
http://www.max-boost.co.uk/max-boost/gotchas/useless_mods.htm
Enjoy – I know I have, and taken away quite a lot of useful information too []