Will an axel-back exhaust add power? And if so how much?

 

A negligible amount. Probably in the 5 to 8hp range....and it's probably not even throughout the entire power band. The gains are so small that even Stillen doesn't advertise the gains or show a dyno graph on their website like they usually do. If you do this mod, it's gotta be for the sound, not the HP/TQ increase. Same with your CAI/HAI question you asked.

Sorry to say, but if you were expecting to mod this car and pickup up some noticeable power gains, you bought the wrong car. Infiniti Q50 red sport is super mod-friendly car.

 

So I’m running the Stillen intake (dry) and the Stillen cat back exhaust on my SR. Did it give me any extra horsepower? All I can give you is a maybe. Feels peppier.

Does the car sound amazing? Oh yes. The intake howls when you’ve got your foot in the pedal and the exhaust has a nice drone free rumble when I’m getting my groceries. FWIW.

 

Short answer is no. Nothing added after the cats will do diddly squat, but the sound will make your engine sound more powerful!

 

Agree...some times sound is very soothing. I had a 2004 GTO.......I am not sure I ever turned on the radio during my 2 year lease. I drove in the winter with my window down just to listen to the exhaust note. It was intoxicating from the factory,