Upgrading the TURBINE TUBE, also known as the downpipe will have the greatest impact on the 1989-1994 Nissan 240SX S13 turbocharged vehicles. Turbo efficiency, power, and response is greatly improved with a more free-flowing turbine tube. Each downpipe has an EGT Bung with cap for those who wish to monitor exhaust gas temperatures without having to drill into their downpipe.