Mistubishi 4B11T EVO X. 'PACALOY' Beehive valve spring set with titanium retainers. This spring set has been designed for the serious racer for high rpm, high boost racing applications. 85lb seat pressure at 34.2mm installed height. 185lb at 11.5mm valve lift. Coil bind 21.0mm. Suits up to 10,000rpm and 50psi boost.