This site cracks me up sometimes.
There is some good info and respectable dudes just in this thread, however people like HayzTawil really piss me off.
Instead of putting out a post saying how your right and 4ages are the bomb and everything is shit, maybe turn that into a question then read the reply of these people to debunk your theory or "knowledge".
In short cause there's probably too many words for you....read more, listen less to your mates and ask questions.....
To the original poster. 6k will get you nowhere with a sr20 going into your ke**.
If you want to spend 6k on a sr20 to make "Heaps of power" this is not possible with new or close to parts. Second hand probably but tune and install will still make short use of that 6k.
Unna you should read a bit more too and try getting some quotes on parts instead of asking these questions....you might find out the answer quicker and a bit more reliably.
Sorry for the rant.