what if i had 1 inch rims and big fat tires would that make me have a huge jump in performance?
also if i go to 16's from 14's will there be enough of a power loss to notice anything and will the handling become better or worse?
For acceleration, yes, a 13 inch rim will be better than a 16" rim. That's why drag racing cars have those little itty bitty rims with those huge tires. Also, if you have enormous amounts of torque, then the tire with huge sidewalls can kinda act like a slingshot and kinda throw your car forward.
Now for handling, that's a different story. With such a huge sidewall, you're going to have very crappy response time with turns and lots of sidewall flex which is bad. For a happy medium, I think either a 15" or 16" rims is best on B15 sentras.
If you look at all the road racing guys who need both acceleration and handling, they usually go for something middle of the road with either a 50 or 55 series tire.