This is a slow, fuel rich reversionary pulse wave in the intake tract. The reverse of this is also true. Detonation is an extreme lean condition that generates a sharp reversionary pulse wave. Remember that we are moving a very light weight emulsified fuel charge. This is the reason it is so responsive to the engine's fuel needs over such a broad range.
Throttle response is extremely fast and smooth.
Throttle lag is virtually eliminated. Throttle lag is where the airflow in your carburetor out accelerates your fuel, which finally catches up. Modified or piped machines will have fuel needs that require a higher fuel curve when the pipes and modifications kick in. In other words you need one fuel curve when running below peak and another fuel curve at peak horsepower. This is why a piped machine is so fussy to jet.