RTR 3/8" thick G11 phenolic intake and throttle body spacer gaskets with a 1.8L intake that will replace the 1.6L intake. Heat is dissipated through the phenolic spacers keeping the intake air cooler when it enters the engine. The factory 1.6L DOHC intake has a 2nd stage, 8 individual small ported plenum intake piece with a vaccum controlled butterfly blade rail restricting the air flow. The factory 1.8L DOHC intake is still a 2 piece, but Isuzu totally eliminated the 2nd stage blade rail and made the lower intake plenum with 4 larger ported chambers instead of the smaller 8 chambers in the 1.6L intake, allowing much more air to flow to the head. More air, more powwa!