[avengerr91]

Hi. I have a 2017 X1 SDrive 18i. I'm already running a tuning box on it and the gains are noticeable. However, I was looking to add more power to the car but basically found that adding a CAI is worthless for power gains. Therefore the other option I'm considering is to go for a custom cat back exhaust system.
I wanted to know whether adding a cat back exhaust system would add any hp or is that useless without a downpipe?

[billnchristy]

Engines make power from air flow, fuel flow, spark, and getting spent air/fuel out. If you have a tune already an intake may help a little.

I don't think a cat-back would really get you anything but cool noise, a high-flow cat or catless downpipe would be where some flow gains could be had.

Like I said though, by increasing your boost you do have a need for more fuel and air, a full exhaust and a proven high flow intake could work wonders.

[avengerr91]

Which Intake would you recommend? I'm leaning towards the Dinan CAI.

[billnchristy]

Seems like a good choice. What tune box do you have?

[avengerr91]

I'm currently running the TDI Tuning Box.