Racepak This V-Net module is used with Racepak's turbo shaft speed sensor (PN 800-SS-TBRPM) to monitor turbo shaft speed by detecting a machined surface on the turbo shaft . This is an effective way to measure the efficiency of a turbocharging system. Compatible with all Racepak V-Net systems, data loggers and dashes. Turbo shaft sensor (PN 800-SS-TBRPM) sold separately.