SZs new unique design improves upon our older super splits by increasing the overall diameter to 3" using a coned expansion process. The reason this type of down pipe works better is because the exhaust coming off the turbo wheel is spinning extremely fast and whipping in a circle. If the exhaust comes off the turbo wheel and enters a much larger area, it becomes more turbulent slowing the exhaust velocity. In addition, when the wastegate opens the two turbulent exhaust gases fight each other causing more turbulence. By keeping the exhaust in a pipe similar to the size of the exhaust wheel and separating the wastegate, you dramatically speed up the velocity of the exhaust gases, causing the turbos to spool about 500 RPM sooner than an open pipe design.