The air demand for the engine is dictated by the supercharger,it effectively "sucks" its requirement for air dependent on its rpm and volume- if this demand is met then there is zero pressure pre charger - IF there is a restriction to the air flow a vacuum develops,and the speed of airflow is affected ,this vacuum uses power from the charger and shows as heat .
The effect of a larger throttle on the S will be minimal as the charger air demand is not greater than the ability of the throttle size (stock) to provide it.
When reducing the pulley size the charger rpm increases and the airflow requirement also increases this can get close to the throttle size limit if rpm is increased high enough ,but at that point the charger is suffering anyway with other losses.
The stock charger is rated around 330CFM or just over 210bhp mark ,when pullied this increases ,but I suspect its only at a much higher CFM that the throttle is challenged.
The opcon outsucks the stock throttle ,and lost a fair bit of power by generating a large vacuum,this has been one reason for modifying the intake pipe and trying larger throttle .
A less restrictive air filter also helps the stock charger in this respect,but does allow more noise
Anything that makes the chargers life easier will help |