The stock down pipes cause a major restriction in the exhaust flow. BMW's solution to deal with the limited space in the engine compartment is to crush the turbo outlet tubes to reduce the size of the tubing. Doing this created undesirable backpressure. For emission purposes the factory also incorporated built-in pre-cats directly after the turbo outlet ports. This make the exhaust gas backpressure rise to extremely high levels at all rpm and engine loads. This design retains excessive heat in the engine and affects performance in a negative way.
On the contrary, the design of the Supersprint down pipes takes advantage of even the smallest space available and frees the exhaust gas flow dramatically. The SS pipe cross section (no crushed pipe) remains constant all along the down pipes and the pre-cats are totally eliminated.
Down Pipe Benefits - 65mm pipes for superb air flow and for maximum performance gains - Frees up horsepower and torque - Deeper, throatier sound
***This product is legal only for racing vehicles that may never be used upon a highway and is not applicable or intended for street or highway use.
