AirBox Lower Intake operation (Video)

This Video shows what the lower airbox intake assembly looks like and how it operates.

After putting in my KKM cone filter I removed the lower intake assemble to prevent it from fast tracking water towards the air filter. The system is comprised of four basics parts: Engine vacuum, Bi-metal sensor, vacuum actuator, Air duct

Click thumbnail for larger picture


The Bi-metal sensor (not pictured, but located on top of the stock airbox) functions like a temperature switch either sending or cutting off engine vacuum to the vacuum actuator in the lower intake assembly.

When cold the Bi-metal sensor allows vacuum to pass through to the vacuum actuator. This allows air from the exhaust manifold to enter the air box while simultaneously closing off fresh air from the nozzle behind the bumper.

When warm the Bi-Metal sensor cuts off vacuum to the vacuum actuator. This allows fresh air from the Nozzle behind the bumper to entire the air box while simultaneously closing off hot air from the exhaust manifold.

Note: The vacuum actuator is a normally open. Therefore if the vacuum hose is removed/damaged it will keep the air vane open (allowing fresh air side to pass).

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My hose from the airbox to the exhaust manifold was removed because it was torn appart by climate and winter conditions...so does it really mater if i removed it ?
Should I also unplug the little vacuum hose and plug it because anyway i think its better to get cold air from the front inlet than from the side????

thank you

SexyFantome said:

My hose from the airbox to the exhaust manifold was removed because it was torn appart by climate and winter conditions...so does it really mater if i removed it ?
Should I also unplug the little vacuum hose and plug it because anyway i think its better to get cold air from the front inlet than from the side????

thank you

Click to expand...

Since yours is removed do you notice any difference in how the engine runs/performs? IMO directing warm air from the exhaust manifold into the stock air box doesn't matter that much. To clarify the purpose of the lower intake assembly is to help the engine reach its normal operating temperature quicker by sending in warm air from the exhaust vs cold air from the intake behind the bumper. Once the engine as reached its normal temperature then its ready for all cold air.. Of course if you live in a very cold area where temps are routinely below 0 deg then maybe you'd notice some difference in how the engine runs.

I live in Quebec and its winter here so maybe I should unplug the diaphragm and plug it with a golf tee. So like that the air will always come from the front of the engine. I wanted to ask something too about the vacuum ...Theres a T valve that become open if the below line suck air but i have no vacuum at all regardless of engine running condition and temperature. Does it really mater?