GSC Intake Valve Guides Stopper Style - Subaru WRX 2002-2014 / STi 2004-2020 (+Multiple Fitments) Audi-A4-2018 The chromoly flywheel is lighter

The chromoly flywheel is lighter than OEM for improved engine response

Stronger “urge”

2400 lm per bulb

The increased flow of air through the filter provides a steady stream of clean air to the engine

GSC Intake Valve Guides Stopper Style - Subaru WRX 2002-2014 / STi 2004-2020 (+Multiple Fitments) Audi-A4-2018 The chromoly flywheel is lighterWhat they have done is actually quite simple, they made valve guides that fit properly, are easier to install, and shaped to help air flow instead of just copying the OEM design. The GSC Power Division valve guides are made from true C67410 Manganese Bronze and turned on a dedicated precision CNC turning center. What this means for you and your installer is less time fitting guides to the head due to holding the tightest tolerances in the industry