The Borla XR1's are pretty damn loud.

 

I really hate to sound two sided but will I be able to get as much performance out of those twisters as I would out of those bullets?

 

Dynomax Ultraflows are very quiet. I have a true dual
setup that is over the axle and through an Ultraflow
muffler (two straight through passes in a single muffler)
and it's really quiet. Way quieter that my previous
Flowmaster.