| | Ferrari 458 Italia
There is always a ton of questions about this and while it does seem like ram air should do a little at least, it's not worth the time people put into it. It doesnt take an engineering expert to know that fresh air is always better but the reason turbos and s/c work is because they compress the air, not just move it faster (which has been discussed at great lengths).
But what should be the final answer comes from recent articles in Car and Driver, Road and Track, etc about the new Ferrari 458 Italia. Ferrari claims the ram air system makes a whopping 5 hp at 200 mph. The fact is, most of our cars wont hit 200 and dont go too much over 110-150 in the quarter. So along the same lines you might get 3-4 hp tops at that speed. And the ricers that always talk about squeezing every last hp dont even hit 100 so you're talking 2-3 if you're lucky.
Bottom line is, do the free ram air mod if you want a few FREE ponies, get a ram air hood if you like the LOOKS. Get a turbo or s/c if you want the POWER.