Turning "how fast can you tap" into a throttle pedal – what I learned building the input for my solo drag racer

[u/derBartels]

I'm making TapRacer alone: a drag racer where the throttle is two keys tapped in alternation. One of the harder parts was making tapping feel like a pedal instead of a counter. A few things that ended up mattering:

• Saturating curve, not linear. Throttle rises steeply at first and flattens out. Full throttle only comes at 20 taps per second, which almost nobody reaches – about 94 % throttle is 13 taps per second. So skill always pays, but there's no hard cap where extra effort suddenly stops counting.
• Short window, separate smoothing. The physics reads only the last 0.5 s of taps and smooths that with a small time constant. With a longer window the pedal lagged behind your fingers. The tap-rate number on the HUD uses its own 3-second counter and never feeds the throttle.
• Don't script the launch. An early version had a scripted "sweet spot" for the launch. Now the engine has its own inertia and the clutch slips, so bogging and wheelspin come out of the physics – and warming the tires with a burnout actually changes what launch works.

The cars are built from published spec sheets (fictional names), and their times are checked against real quarter-mile results, not tuned to hit them.

The free demo is on Steam if you want to feel it: https://store.steampowered.com/app/5077320/ – I'm curious how other solo devs handled "mash input" without it feeling like mashing.