Racepak The V-Net Turbo Shaft Speed Sensor allows users to determine the efficiency of their turbocharging system by measuring turbo speed. It is designed to pick up speed by detecting a machined surface on the turbo shaft. Sensor thread is 3/8? x 24 NF. This sensor is used with the Racepak V-Net Turbo Shaft Speed RPM module (230-VM-TBRPM) sold separately. Compatible with all Racepak V-Net systems, data loggers and dashes.