Thanks. Good eye! The brake and clutch do use hydraulics for feel, the throttle uses just spring tension. The slaves actuate high resolution pots that are wired into the connector box and link up via a short 5 pin DIN cable to a Beta Innovations Plasma Lite that lives under the hood (the enclosure the TV sits on) along with the steering parts and other electronics. I may at some point change the brake over to a force sensor actuated by the hydraulics, but it works so well as it is, that it would be mainly be a tinkering type project.

The wheel mounts up on a QD hub for a kart and the buttons connect to the Plasma Lite via a the coiled pigtail to a socket under the dash. The shifter unit mounts to the right side of the chassis and uses a DB9 serial cable to connect to the Plasma Lite.

I'll try and get a couple more pics of the pedals up in the next few days.