it helps the engine to breathe air better, and colder air at that, ... it can only help!

 

I would be surprised if the VFlo, headers and Cats give me more the 20Hp combined. I would save your money and spend it on the suspension, I found the overall performance of the car increased more with the Damptronics and sway bars, then the full exhaust/intake that I have. The cats provide the most gains of the exhaust mods, and they made the car sound a lot better.

 

I already have everything except intake and chip at this point. Its an everyday car so I want to keep the suspension just the way it is, maybe with some swaybays but definitly not tightening up the suspension. I drove a car with some aftermarket suspension and it was a HARD ride, stiff as can be! would not be fun for everday use!

 

My opinion on the intake is that unless you are going to do the throttle body along with the better intake manifold runners it probably by itself won't be worth much. You can get most of the benefit of the X51 package without doing the heads by doing the above. It will cost alot more than just the cost of the X51 airbox as you now have to buy the throttle body along with the intake manifolds. Also the install now just got a lot more complicated. If you notice however even the non X51 intake of the S is a dual intake setup, it is worth something but not much by itself. The X51 heads receive some bowl work and a stiffer exhaust spring so Porsche can raise the revlimiter to 7400rpm. At best there isn't more than 5hp with the better heads.

Dave