Valve spring Audi V8 40v 4.2L / Audi A8 / S4 / RS6 2003 - 2008 ST-SPR-H1002D/AU

All Supertech valve springs are made of Superclean premium chrome vanadium steel alloy for higher performance and durability at high RPM. The use of a high quality steel alloy provides the added benefit of better structural memory for all our springs. Our valve springs are computer designed, to ensure stress levels do not exceed the stress limits specified in the fatigue charts. Combined with our high-quality steel alloy, it gives Supertech valve springs greater strength in extreme conditions, giving the racing engine a serious advantage in both performance and durability. Supertech tappets are Manufactured from high-quality military-certified titanium alloy and CNC machined to ensure a tight fit Our high quality tappets are among the best in the industry Fits: Audi V8 40v 4.2L / Audi A8 / S4 / RS6 2003 - 2008 Dimensions: Outer diameter with Inner Spring Diameter: 29.1mm Inner Outer Spring Diameter: 21.9mm Inner Spring Outer Diameter: 20.5mm Inner Spring Inner Diameter: 15.5mm Compressed Pressure: 75@33.7mm Expanded Pressure: 180@10.5 lbs Maximum Pull Out: 14.2mm Compressed Height : 19.5 mm Hardness: 10 lbsAll Supertech valve springs are made of Superclean premium chrome vanadium steel, which ensures higher performance and durability at high revs. The use of high-quality steel alloy provides the additional advantage of better structural memory for all our springs .Our valve springs are computer designed to ensure that stress levels do not exceed the stress limits specified in the fatigue charts.Combined with our high-quality steel alloy, Supertech gives the springs greater resistance under extreme conditions, providing the race engine with a major advantage in terms of both performance and durability.Supertech cam followers are manufactured from a high quality, military-grade titanium alloy and are machined on a CNC to ensure a tight fit.Our high quality followers are among the best in the industry.Fits: Audi V8 40v 4.2L / Audi A8 / S4 / RS6 2003 - 2008Dimensions: Outer diameter of the outer spring: 29.1 mm Inner diameter of the outer spring: 21.9 mmOuter diameter of the inner spring: 20.5 mmInner diameter of the inner spring: 15.5 mmSeat pressure: 75@33.7 mmOpen pressure: 180@10.5 lbsMax net lift: 14 , 2 mmCoil bind: 19.5 mmRate: 10 lbsReferences: Included: Cam follower RET-AU5VE / T4 + Valve seat SEAT-H1000 (16) - exhaust valve