We are always on the look out for serious quality parts that help our Supras last as long as possable, and make the most power as well. The factory tensioner is a cast aluminum piece that can crack and even break over time. When this happens the timing belt comes off and all your valves get bent and usually the head is destroyed as well. This is a scary thought, espically if you have invested in camshafts, springs, retainers, valves..... The solution for peace of mind and performance: The TMS Billet Tensioner. The tensioner is a billet piece of steel that will never break or distort under any normal load that can be applied by large duration and high lift cams, or even high RPM. This is a security policy for your very expensive cylinder head. We run this item on ALL of our JZ engines.