These engines have no where near been exhausted? 2 Turbo setups does not in my mind define an exhausted modification route. No one has as yet truly explored the NA route for the street with definitive numbers. There is 1 S/C car in NZ with another on the way here. There's also several other options going around the place which have not been demonstrated here as well... This forum is not the be all and end all for these cars and these engines, but it has good info and if you search you can find answers to most questions. But, at the end of the day, nothing beats getting out and finding all the info for yourself, that's what I've done, that's what Bill's done, that's what several other people here have done. Some of the information found has not been covered here at all, and this is mostly down to people not asking the right questions ;) Once you start looking deeper into the issues involved in modding cars there are countless things that come up along the way...