Mk1 Focus RS - Zetec Blacktop + ST170 AREA6 Up-rated Valve Spring Set Engine Bay Perfect for Focus RS mk1

Perfect for Focus RS mk1

0L engines

Easy to apply and can be cut into strips

Genuine Ford Plastic ECU and Module Bracket for Mk1 Ford Focus RS

Mk1 Focus RS - Zetec Blacktop + ST170 AREA6 Up-rated Valve Spring Set Engine Bay Perfect for Focus RS mk1Turbocharged 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,