Of course, the simplest answer would be “not to open”. Or “such rules”. And both of these answers are correct – additional locks or straps must prevent the dangerous opening of the hood. But even very fast street cars, including the fastest supercars, don’t have such tools. It is not directly related to speed.
Jaguar XK120. Many old classic racing cars have leather strapped hoods. (Jaguar MENA, Wikimedia (CC BY 2.0)
The hood can be opened from the outside
The hood of your car is opened by pushing a handle in the car interior. This is not suitable for racing cars as sometimes the interior of the car may not be accessible. For example, firefighters arriving after a serious accident may not be able to reach the handle in the cabin, and the mechanism itself may be broken. Simple external pins or straps allow you to quickly access the engine compartment, disconnect the battery or extinguish a fire that does not start (if the car does not have an integrated fire extinguisher).
Quick access to the engine compartment may also be necessary during a service lane stop during the race, in which case the external locks may be faster.
Dents and scratches
Yes, hoods do not automatically open from speed, especially if they are opened forward. But racing is sometimes a contact sport.
