Boosted Falcon

Well. ive got an EF and an EL XR6.
EF has Wild Cat 21 Extractors hollow cat and 2 1/2 pipe with 1 muffler and twin dump tip.
EL has Pacemaker 4499's Cat and 2 1/2 pipe with 1 muffler and standard XR6 tip.

the EF sounds heaps louder then the EL when they have close to the same stuff.

how can i make it louder without making it illegal

might be the gutted cat making it louder also the muffler on the ef may be a higher flow since its a different brand.