New to the .org. Great site!!

If I were to install a new intake, lets say Frankencar for example, is there any point in staying with my stock exhaust system? Or is there an aftermarket exhaust system I could put in that will be just as quite as my stock?

 

Yes your stock exhaust is actually quite good for a "stock exhaust." If you were to go to a cat-back system then you would gain maybe about 5 HP at most. The only real gains in changing your exhaust are for sound if you are NA or for increased performance if you have NOS, Supercharger, or Turbo.

 

First off welcome to the org...

Now to your questions. By adding a full exhaust with Y-pipe you'd get anywhere from 10-20 hp. You have two ways to keep your exhaust quiet. First you can not add a Y-pipe. The other way is to keep your OEM muffler. Either way you go you should keep a relatively quiet exhaust without drone.

If you do decide to get all aftermarket exhaust like I did, your car will be plenty loud at all RPMs and most likely will have a drone when you reach your cruising speed.

A lot of people will tell you to use the search button on the upper right of the screen before asking questions on this, as it has been discussed thoroughly. Hope ths helps you out!