On our spec sheet from last year it says 180mm for CoG. Obviously just a made up number. I decided to tip the car up to balance point with a driver in it, and got to 70.5 degrees, or 19.5 degrees from vertical. (Driver was both amused and concerned). Noting the car was sitting on the tyre sidewall I added 20mm and calculated our center of mass was about 345mm from ground with current setup. (We have more ground clearance than we need). Since we are reducing the tracks this year we should also reduce CoG, but just as important I want the driver looking good, not obviously sitting too high. I note the drivers weight could be 25% of the car, so drivers CoG has a significant contribution so I want to push the driver down a bit. Thinking how to design a new car, I came up with this:
Flow chart to establish low driver position and design chassis cockpit.
Establish a floor or reference plane as the lowest point possible.
Draw rollhoops 800mm apart like our old car for a starting point.
Find the steering rack height, used to define heal position. (Our rack is at the bottom, but just above the lower wishbone).
(Heels maybe 100mm above bum).
Set minimum front rollhoop height for 350mm template rule and to clear steering rack.
Set seatback angle (try 45deg, 2014 car was 51deg) or until a 175cm persons visor is above the front hoop.
Set steering column height and angle by drawing a line from toes to chin.
Steering wheel distance ~340mm from chest, or elbows at 90deg.
Set main hoop height using Percy template (95%ile male) or tallest driver, 2“ rule. Allow extra height.
(Shortest driver will need foam to see over front hoop).
Pedal box adjustment is XXmm (5%ile to 95%ile).
Set harness bar height from rules.
Check steering wheel is not higher than front hoop.
Also, I am fishing for comments on my current theory that the steering column should be on a line drawn from the toes to the chin, or near enough, regardless if your driving a F1 or a truck. The theory holds for the sedans I drive.