Throttle Body Spacer
It increases the size of the plenum. I can't remember the philosphy of what makes that better, but it can make a difference.
Long runners (from butterfly to valve port) give more torque, short runners give more horsepower. Some race engines (787B from memory) were built with adjustable runners
that car is sick! but im not a fan of the wankel rotary its pretty horrble to fix
throttle body spacers on newer cars are useless, as they are good for is a fricken loud as high pitched whistle that gets annoying after time, the ECU management of newer cars only lets in enough air as it needs and controls everything, unlike older carburated vehicles and early TBI where it shows great gains in power and torque for what it is.