Intake setups boxed vs Intakes not boxed / sealed up
The intake temperature is one of the most important factors in making power.
Hot temps have a snowball effect on turbocharged vehicles.
- When the temperature increases, the air becomes less dense and so the car will make less power by default.
- Hot temperatures heat soak the heat exchanger, its coolant and make it less efficient.
- Hot temperatures cause the car to become more knock prone.
- Hot temperatures cause the car to reduce ignition timing via the Intake Air Temp Ignition Timing Compensation Table. This is the main reason the cars feel slow and sluggish when it's hot outside. This table is also one of the main reasons most people run less than optimal 1/4 mile times. Heat soaking in the staging lanes causes the IAT to increase and the car can be missing 2-6 degrees of timing the whole 1/4 mile.
With that said it is always beneficial to run an intake that has a box or is sealed up against the engine bay heat. As a quick example if you are out for a jog and you get heat soaked, you run less efficient and slower, so does your engine when the IAT temperature is high.