Originally Posted by vic325ci
...actually it adds 3% which is about 7 hp on a 330...and if you're worried about inefficiency, then you might as well get an M3
3% on paper? I really want someone to prove me wrong and demonstrate that underdrive pulleys actually have these gains on a dyno. Regardless, anything under 10hp gain remains basically unnoticeable.
To the OP, why not get him some LED tail lights to update the look of the rear? They'd only run about $250 shipped, or in some cases cheaper. I'd really like to know where and how an Mtech bumper could come under $500 painted.