Integrated Engineering Valve Spring & Retainer KitThe IE Performance Valve Spring & Titanium Retainer kit features optimized spring rates explicitly designed for your Audi 4. 0TT EA824 engine (C7 C7. 5 S6, S7, RS7, & D4 S8). Engineered with exacting specifications to provide proper valve control preventing valve float in high power and high revving applications. REV HIGH WITH CONFIDENCE Increasing your engine's power output often comes with modifications that require more RPMs to get the most out of