Hondata has developed a special high temperature insulating gasket which replaces the stock intake gasket. The Miata manifold is heated in up to 5 places - From the cylinder head, the cold idle valve, the idle control valve and the throttle body heater. Hondata's new gasket coupled with bypassing several heat sources significantly reduces the transfer of heat from the cylinder head to the intake manifold and incoming air giving you up to 5% more power. The intake manifold is made of aluminum and because it is heated by the cylinder head from combustion and coolant, it works to increase intake air temperature by as much as 75° F. In fact, for every 5° F rise in intake temperature, air density drops 1%. The hotter the air, the less fuel the computer injects to compensate for reduced oxygen. Around town, testing has shown an average drop of around 20 degrees F which is good for a 3 percent power increase. In certain conditions a 50° F drop has been measured. The Heat shield gasket kit contains an insulating gasket and installation instructions.
TO ENSURE AN ACCURATE FIT, use this chart to order your correct helmet size. Carefully measure around your head, above the ears. Take the measurement, in inches or centimeters, referring to the sizing chart below for your correct hat/helmet size. Helmet must fit properly for optimum performance. Don't guess your size. Helmet must be securely and snugly fastened before engaging in any activity.