I developed the newest exhaust design to improve turbo spool time and overall system efficiency. It incorporates EGT thermocouple bungs 2″ downstream of both exhaust ports and a Delphi Mini O2 sensor after the turbo. The new header design allows the system to be removed without rotating the engine for easy access to the transmission output shaft and engine cam cover.
I used 1.75″ diameter mandrel bent .040″ wall thickness 304 stainless steel tubing for the exhaust primaries and 2.00″ diameter .065″ wall 304 from the collector to the turbo. The wastegate branch is 1.5″ diameter .065″ wall 304 tubing. The turbine inlet flange and wastegate flanges are 3/8″ thick 304 and the turbine outlet/mounting flange is 1/2″ 304. The turbine outlet transitions from 2″ to 2.5″ and the wastegate dump merges with the 2.5″ exhaust outlet.
I made a special turbo oil drain fitting with a -4 AN fitting and allows 360 degree clocking of the compressor housing. The oil is pulled from the drain fitting by a electric scavenge pump mounted at the rear of the primary cover and returned to the oil tank in the swingarm.
I added a 2.5″ aluminum extension to the compressor inlet to allow for a larger air filter and better positioning.
The intake ducting is .065″ wall thickness 2″ 6061-T6 tubing. The black length runs from the compressor outlet up along the primary cover to the hole in the left frame rail. The natural aluminum length connects right below the frame rail and runs up through the frame and over to the coupler at the throttle body. The threaded bung is for the water injection jet and the Turbosmart blow-off valve sits right above the throttle body.