The M97 engines esperienced huge improvements over the M96, however, there still exists fracturing of the windings, and valve float, especially with the Variocam added weight. On street, boosted and high RPM activity, this is the perfect solution for the flat 6, potent powerplant.
A beehive configuration, on both intake and exhaust, which prevents harmonic frequency damage seen with factory valvetrain parts, and weighs in at a feathery 55.6 grams for both the spring and retainer. This also is much lighter than the dual spring setup on the intake of some models. Tested to 10,200 RPMs, without valve float, with factory valves. 12.8lbs/mm sis the spring rate.
Compatible with the 2005-2008 Porsche 911, Cayman, and Boxster, both base and S models. These are the same valvetrain parts on the Bisimoto Biturbo Cayman S.
Price is for a set of 24, with the custom windings, titanium retainers, and hardened seats. Free shipping, worldwide.