i heard of this thing called a vc turbo engine and how it works is that it uses 2 joint thingies for the pistons and it can adjust its compression ratio for performance or efficiency
Variable compression on its own may be too difficult to implement with the game in its current state - you’d have to set a compression ratio range (with minimum and maximum values), and this would cause the power output to vary depending on the current compression ratio, which would cause the car’s stats to go all screwy.