It's a term dating back to the 1970's that describes 4 upturned exhaust pipes or headers on each side of the car

Removable 30mm Cooling FanIntegrated 4mm Bullet Connectors

and get your gear ratio dialed for any track condition

0V sec/60):

Ideal for 1/10 on road vehicles

Futaba - 4GRS 2.4GHz T-FHSS Surface Radio System w/ R304SB Receiver Dubro It's a term dating backFutaba 4GRS Features: Servo reverse End point adjustment Fail safe function Exponential adjustment Servo speed Throttle acceeleration A. B. S. Function Steering dual rate Select switch dial function Brake mixing Programmable mixing 4WS Mixing Dual ESC mixing Gyro mixing CPS mixing Data transfer Timer feature Transmitter Specifications: 2 Stick T FHSS surface system Current drain: 150mA or less Operating system: S FHSS, T FHSS Power supply: AA Dry cell