My names Josh, I bought an 07 cooper s last year and am now wanting to do some performance upgrades. I have done work to cars before, but am looking for advice for a mini. My car is 100% stock right now, but I am wanting to upgrade the turbo to start and not sure what all i need to upgrade along with it. How much boost can a stock engine support?

 

You should start with supporting mods, Intakes , Exhaust , Intercoolers ect FIRST

http://www.outmotoring.com/mini-coop...s/1-induction/

http://www.outmotoring.com/mini-coop...ies/1-exhaust/

Also need a way to tune it :
http://www.outmotoring.com/mini-coop...ooper_r56.html

You really should not just get a bigger turbo and slap it on , you need to do the supporting work first this helps the engine breath and exhaust properly