[Bmwforever9411]

Originally Posted by AmooManiak

Don't listen to these guys. It sounds like you have the N63 engine. The cheapest way to get under 4 seconds in your Xi is a JB4 Stage 2 Beta tune, which costs $799.

http://www.n54tech.com/forums/showthread.php?t=40626

http://www.burgertuning.com/N63_JB4_upgrades.html

You can also do a flash tune, which costs a little more but nowhere near the cost of upgrading to an M6.

Thank you so much. So the only thing I need is this JB4. Do I need any other mods?