Mk1 Focus RS - Zetec Blacktop + ST170 AREA6 Up-rated Valve Spring Set Transmission Why Buy this Bonnet strut

Why Buy this Bonnet strut kit

By expanding the dynamic range and rate of response of your OEM controller

Mk1 Ford Focus RS Carbon Fibre Spark Plug Cover

therefore no thought has gone into the design

Mk1 Focus RS - Zetec Blacktop + ST170 AREA6 Up-rated Valve Spring Set Transmission Why Buy this Bonnet strutTurbocharged and performance engines require more of a valve spring. The pressure within the intake valve is Boost pressure, and this acts upon the valve head, significantly reducing the valves seat pressure as the boost is trying to push the valve open. The same impact occurs on the exhaust valve head. Whilst Ford provided the Focus RS with a mildly uprated spring set to suit the turbocharged application, these become ineffective after 20psi boost,