Adding a cold air intake to your engine will add some extra horsepower but it won't add a whole bunch of horsepower to the engine.
When I added a cold air intake to my old truck a few years ago I only gained 15 horsepower which wasn't what I was expecting as I was expecting to gain more than 15 horsepower but I enjoy working on vehicles so I had fun installing the cold air intake anyway.
So don't expect to gain much horsepower adding a cold air intake however the cold air intake will give you a little more horsepower.