Challenger SRT Hellcat
I always wonder why people want to remove cats. The engineers spent hundreds of hours getting the right flow and exhaust note and then we yank it thinking we will do better. In reality 20hp would be barely noticible in this car. Good cats tend to be less restrictive than the mufflers. We are not in the 70's where the cat would choke the motor. Your better off dealing with the tires than the engine. Overhead valve motors need back pressure to run right and to keep the torque numbers up. The computer connects the dots to make sure the right mixture is there for all this to happen. Open exhaust is fine if you just want to track it but creates more problems with drivability. I always tell people that for every action there is a reaction. I would suggest that unless you are an engineer I would shy away from these mods and stick with improving times with tires or even a future mapping of the computer when that comes out.