Welcome to Challengertalk You say straight pipes, so I assume no mufflers too? If so, all you have is pipes after the manifolds. Beyond headers, cutouts are the only other thing I can think of. If you want the ability to make it behave when you want, get a full cat back exhaust and cutouts. At the flip of a button you can sit at idle next to a cop and be able to look over at them, lol
A Guy
A Guy