As someone who has tuned engines, I totally get the cool air argument. In your example the delta is 20 degrees = 3hp. That assumes you can duct to ambient air temperature which short of having a ram-air scoop or ugly ducting is probably not going to happen so the hp difference is maybe more like 2hp?
Now, in my case, I'm not looking for ultimate power as I find my +8 pretty quick as it is. So my modification is about the aural pleasure of hearing the intake howl plus the visual pleasure when opening the bonnet. So basically, we are all correct!
