Tomei Titanium Valve Spring Retainers Mitsubishi EVO X 2008-2014 / Hyundai Genesis Coupe 2.0T 2010-2013 ( 4B11/G4KF ) An indispensable part for any high powered, high speed engine. The combination of high lift camshafts and oversized valves will greatly increase the flow rate for fuel mixture to enter the combustion chamber. When upgrading the Valves to cope with the new high lift camshafts it is also a requirement to upgrade the Valve Springs to suit the new setup. High engine speeds and the dynamic movement of the valve trains mass can cause unwanted stress loads. This can cause abnormal movements such as a Valve jump or Valve bounce which can cause engine failure. The Tomei Retainers are made from Titanium alloy for added weight reduction whilst maintaining the high strength properties and precision required for the nature of its use. This will help keeping the Valves under control and secure the Valve in place during extreme race conditions. Will work on both Mitsubishi EVO X 2008-2014 & Hyundai Genesis Coupe 2.0T 2010-2013 ( 4B11/G4KF ) WEIGHT & MATERIAL The strength and weight characteristics of this material showed best results during test conditions of 5,000 revolutions per minute during the load conditions from the valve spring and camshaft. PRECISION The light weight design aids with smoother operations and provides improved dynamic balancing to the valve train. The valve retainer?s precision is an absolute must to secure the valve and valve spring in place. The TOMEI precision design guarantees the optimum smooth operation process of opening and closing of the valves. UNNATURAL VALVE MOTION ?JUMP When the cam lob passes the peak point of the lobe and the valve lifter then returns, there are time when the valve spring is not capable to keep up with the large cam lift design and causes the valve to crash into the cam. This can cause the valve to jump and or bounce repeatedly. Left unattended to can lead to terminal engine failure. ?BOUNCE When the valve closes after contacting and not staying seated the shock can cause the valve to rebound repetitively causing damage. Due to the phenomenon of the Valves movement following the Camshaft the impact on the Cam and the Valve seat is great enough to cause damage to the Valve and there are times when the abnormal rebound can cause contact with the Piston. The phenomenon easily occurs when the motion of the Valves mass is great so attention to detail of the weight of the dynamic Valve Train is vital.