We based this design on the fabled 997 4.0L GT3RS. It features dual conical air filters from the 4.0RS.
On a stock car this airbox will free up about 5-7whp.
On a Dundon Race Header equipped car, this airbox is good for about 8-10 whp!
Note Fan Part 997.624.056.05 is required for fitment on cars with the original thick fan (most of them have been replaced by 997.624.056.05 by now...) If you need to source it or are unsure, you can order our option that includes a new fan slim line decklid fan from Porsche.