Drop in filters do not add any hp unless you are replacing a clogged factory filter.
The benefits of a true cold air intake come from drawing in cooler outside air, using a cone shape filter with a much larger surface area, a smooth intake tube that is less restrictive than the accordion shaped factory tube, and heat dissipation.
Vararam has proven to be the best performing intake at the track simply because it is the only intake that pulls in air from the front grille which is the coldest air you are going to get. It also does not have any 90* bends in the tubing which gives a more direct shot of air into your intake manifold. It also seals off to the insulated liner under your hood to prevent any engine heat from being sucked into the motor. And finally, it has a heat shield under the airbox that prevents engine heat from soaking into the airbox. With all this extra air does come more dirt and bugs though, so the filter will get dirty faster.
The S&B is a close 2nd when it comes to performance and will offer a little more protection to the filter if you live in a dusty area. It has 2 inlets to bring in twice the air as the stock airbox, has a smooth 4" intake tube that tapers down to 3.5" at the throttle body, has a big cone filter with a lot more surface area than the stock panel filter, and an enclosed airbox that keeps engine heat away from the filter.
You probably are not going to feel the gains from an intake at part throttle, but they are measurable at WOT. Doesn't matter if you are on the street or at the track, when you go WOT, that is when you will feel the gains of a true cold air intake.
