When I was Building my Z31 I was having an issue with the stock S-Pipe slipping off the turbo and causing issues with letting un-metered air into the intake system and this was causing a rich running condition. The Stock S-Pipe is also one of the most restrictive areas of the Z31 Stock intake system.
In 1985 The 200ZR was Created and was the last of the Z cars to have a straight six engine. Nissan dropped the L-series motors and instead used the RB20DET motor in the 200ZR. The RB20DET is a Inline-6 2000cc Twin Cam Electronic fuel injected Inter-cooled Single Turbo and is the same motor used in