I am thinking of getting a 2002 S80 T6 and would like to tune the engine. I am wondering how much power I can make before the transmission or anything in the driveline breaks.

Edit: Sorry for posting this here. I didn't read the "do not post tech questions here" thread. Could someone move this to the proper forum?

 

300Hp is about the most amount of Hp the tranny can handle. It possibly might be able to handle up to 400Hp at the most.