With the new 2005 MINI Cooper S comes a new supercharger. Since that announcement a great number of MINI owners have been wondering what that will mean in terms of real world driving as well as long term ownership. So instead of trying ask MINI about these questions we thought it would be better to go to the source and contact Eaton directly. Bob Walling, Customer Manager of the Supercharger Business Development in Europe for Eaton, was kind enough to talk with us about these changes to the new supercharger. Mr. Walling has specifically been responsible for the liaison between the Eaton and Customer engineering teams developing the updated Mini Cooper S engine. So if there are answers to be had this is the man to get them from!

Q: It's my understanding that it will include a newly redesigned Eaton supercharger. How does this new unit alter power in the engine?

A:The Supercharger fitted to the revised Cooper S engine is the 5th Generation Eaton Roots Type Supercharger which utilises a unique abraidable rotor coating developed by Eaton and used currently in Superchargers supplied to Mercedes and Jaguar.

The coating allows the unit to be built with lower internal clearances which results in higher efficiency. This can be translated into: Lower power consumption for the same airflow or Increased air flow for the same power consumed. It also enables the roots blower to operate efficiently at higher pressure ratio's.

In the revised Cooper S engine it is used to deliver a higher air mass flow rate which allows a revised fueling regime to modify the engine power curve primarily to offer improved drivability.

Q: Does the coating effect the life of the supercharger in any way?

A:The coating does not affect the units durability in any way having been proved in production by both Mercedes and Jaguar since 2002.

Q: Is the new unit the same one on the MINI Cooper S JCW kit?

A:The unit supplied to John Cooper Works continues to be different to the unit fitted in production and the John Cooper Works package will continue to offer your readers enhanced performance without detriment to the engine durability.

If you have any further questions please do not hesitate to contact me.

We'd like to thanks Mr. Walling for taking the time to answer these questions directly.