How to change vehicle speed in C++ template

I created a new C++ project using the Vehicle template.

However, I can’t find a way to adjust the vehicle speed in the code.
After reading https://docs.unrealengine.com/latest/INT/API/Runtime/Engine/Vehicles/UWheeledVehicleMovementComponent/index.html
I tried editing my Pawn.cpp file with something like:

UWheeledVehicleMovementComponent* Vehicle = CastChecked<UWheeledVehicleMovementComponent>(GetVehicleMovement());
	UWheeledVehicleMovementComponent4W* Vehicle4W = CastChecked<UWheeledVehicleMovementComponent4W>(GetVehicleMovement());
	Vehicle->MaxEngineRPM = 1000.f;
	Vehicle4W->MaxEngineRPM = 1000.f;
	Vehicle->EstimatedMaxEngineSpeed = 1000.f;
	Vehicle4W->EstimatedMaxEngineSpeed = 1000.f;

But it didn’t work.