Intake manifold has asbestos gasket to insulate heat ( from cylinder head ), but the 9 nuts which lock manifold onto cylinder head have no asbestos washer, so heat enters manifold via [i] these 9 nuts [ii] the exhaust gas channeled to EGR valve [iii] * channeled through manifold .[iv] manifold chamber via EAC & Fast Idle valves.
- meant to keep exhaust gas hot, unnecessary & bad in warmer climate ), & [ii] users will use * to heat their seats' spaces, so * will not be >40ºC. To further cool air intake, I use polystyrene & rubber washers to insulate chamber from these 2 valves, glued 3 heatsinks onto chamber, fitted copper wires & hoses ( with water & surfactant ) onto chamber & throttle body. Then air intake is cooler : warm- starts & hill climbing are easier, in even 27ºC ambient air, let alone in hotter weather. These 2 valves' insulations also make Fast Idle valve heat up & reduce idling rpm sooner, & save petrol during idling / coasting. I could not post here a photo of my F20A's chamber & valves, looks like this NG bans any photo.