Supertech Dual Valve Springs for 2006-2011 Honda Civic Si K20Z3 Engines

Dual Valve Springs for 2006-2011 Honda Civic Si K20Z3 EnginesSet of 16 Dual Valve SpringsSPR-H1019DOuter Spring: OD 30.00mm - ID 21.80mmInner Spring: OD 21.30mm - ID 15.60mmType: Dual SpringPress.Seat: 97lbs @ 40.4mmMax Lift: 17.70mmCoil Bind: 22.70mmRate: 14.80mmSPR-H1021DOuter Spring: OD 30.00mm - ID 21.80mmInner Spring: OD 21.30mm - ID 15.50mmType: Dual SpringPress.Seat: 95lbs @ 40.4mmMax Lift: 17.70mmCoil Bind: 22.70mmRate: 13.20mmSPR-H1022DOuter Spring: OD 30.00mm - ID 21.80mmInner Spring: OD 21.00mm - ID 15.50mmType: Dual SpringPress.Seat: 80lbs @ 40.4mmMax Lift: 18.30mmCoil Bind: 22.00mmRate: 11.20mmNote: These Dual Valve Springs require the use of Supertech Retainer Part # RET-HBK-ST or RET-K20A2/T2 - (Sold Separately)Our valve springs are computer designed to ensure that wire stress levels do not overpass the limits of stress defined in the diagrams of fatigue. We also utilize computer software that allows us to ensure that the harmonics are under control. All Supertech valve