Originally Posted by SwissCheese

I've heard some good things about DB Performance. They tuned GrooveStyle's GTM Gamma Motorsports twin-turbo set-up, so I would assume they know what they are doing.

The general consensus here is that after 3 breather mods, you need to get a tune. Since you're up to 3 (CAI, Test Pipes, Catback), it would be a good idea to get one, especially if you don't plan on doing much more.