Funny thing is that I size control valves at work for large industrial control systems. For a drag car like the honda above, I'd imagine there is very little throttle "modulation". Its likely 0% throttle at idle or 100% throttle when running down the drag strip. In this instance, there isn't a great deal of throttling required. There is likely enough traction since its a NA car to put all of its power down in every gear.
The larger the throttle valve, the lower the pressure drop across the valve. What you lose by going to a huge valve is modulation. Driveability goes to pot when you go to a huge valve because at very small valve openings you are flowing tons of air.
I size valves so that they flow 100% of the fluid at 80% of their percent open. This gives good control with resonable pressure drop. When you are dealing with a system that is just off or on, you can go to a huge valve because there isn't any modulation control issues.
Justin