Exactly the same as a real race car, you have a basis frame or monocoque to which everything else is fitted.
The Racecraft GT chassis is the only complete Simracing chassis available today, it has a provision for absolutely everything that the simracer needs to race. - the driver knowing that all of his equipment is securely and perfectly placed, - to give maximum feedback, enjoyment, and confidence in his driving.

The chassis can be made to fit everyone,- the important physical adjustments are -

Racing bucket seat = Forwards backwards and tilt, (further adjustments with recliners).

Pedal block mount = Forward backwards and tilt.

Wheel mount = Forwards backwards, up down, and rotate.

The Racecraft GT chassis is not directly supported under the seat, this allows the chassis to respond to Force Feedback effects from your wheel.
Also if you place a tactile speaker system under the seat, the driver will feel more of the vibrations, with less of this vibration being transmitted into the floor.

This is the absolute basic level of equipment, that will enable you to drive as good as your skills will allow, for as long as you need to - without fatigue.
In a natural driving position using FIA approved seats,You can perfectly position your wheel and pedals which are fitted to the most rigid chassis on the market.

Strapped in your seat with a Full Racing Harness, everything feels solid and real, - from the tough powdercoat finished steel tubing to the heavy Carbon Fibre effect wheel mount (which can be drilled and tapped).

The Racecraft is built with far more welded joints and fittings, which makes for a much stronger stiffer chassis, a close inspection will reveal how each weld is formed or cut back to improve its appearance or strength. The standard of workmanship is of the highest order, we want you to be as proud an owner, as we were to make your Racecraft.

And again as in real racing, you can add equipment to further enhance and improve your racing chassis.
You may upgrade or change your wheel and pedals or perhaps add a seperate shifter,
NIXIM have a Range of addons which provide a solid and adjustable fitting of your new kit.
All of which can be bought and fitted at a later date - to the prepared fitting points already built into your Racecraft chassis.