Shameless Needswings plug here, but... if you want it done RIGHT, these are what you want:

NeedsWings SRT6 Cat Delete Downpipes

Yes, they're expensive but thorough, LOL... You may lose a bit of low-end torque with these, but you'll gain a bit on top-end.

Might be a bit extreme for a N/A, but if you want to remove ALL cats for maximum flow, this is the best way to do it without completely hacking up the system.

I think if Rob would offer these in mild steel (aluminized) they would probably sell in greater numbers... especially just the basic pipes w/o the cutouts. $500 would be an easier pill to swallow for most folks.

Cat-back systems simply don't yield any measurable horsepower on our cars with the factory cats in place. Not to mention, the drone. But a cat removal with the OEM muffler... you get a nice deep tone, horsepower, and zero drone.

In other words, spend $400 on a catback and get noise... or spend the money on these, and get power.

Cheers,