It's all about airflow velocity. If the engine can only take in enough air to fill the 54MM TB, then you will not only see no gains from, but you will see a loss from going larger. You will, however, have better throttle response. More air gets in at part throttle then it did before, which decreases drivability, and decreases peak torque. Unless you are running a lot of air through the motor, such as with forced induction, what you will be feeling is a jump when you start to open the trottle, since you are letting a lot more air in at part throttle.
But do what you wish, it's not my car.
-=B-=

Dude, Boeing called. They want their wing back.

Dark0ne95: There is a butthole on that girl that his going to feel the wrath of 23 yeras of worldwide hate.
Me: Can I put that in my sig?
Dark0ne95: GO right fucking ahead.