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Old 06-04-2013, 07:57 AM   #10 (permalink)
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Originally Posted by hat_man View Post
Told you all I didn't know anything. LMAO. So I guess that's an intake then. If that's the case then if you leave the grille open and the area in front of the windshield is an intake also, then all the air must leave the engine bay from the bottom?

In my un-aero mind then I still have a question. The article says that you need a pressure differential across the radiator to create flow to move air through the radiator. If the area in front of the windshield is an intake, as is the grille area with it's big gaping hole, then would there be more radiator cooling if you closed the area in front of the windshield? Just to use some arbitrary numbers if the grille area has +10 units of pressure and the area in front of the windshield has -3 units of pressure (because it's on the other side of the radiator), this makes 7 units of pressure across the radiator. If you close the area in front of the windshield (making 0 units of pressure) this would make 10 units of pressure across the radiator, right? This is assuming the "exit" air flow is out the bottom of the engine bay. All the other areas are intakes.

And secondly, if all this is true, if you put a belly pan under the engine bay and the grill and windshield area are intakes, where and how does all that air leave the engine bay?

I'm sure there is a logical answer, but I just can't wrap my head around the concept.
Those with more experience feel free to contradict my comments, but one of the reasons I have heard for not dumping engine air on the windshield is that it is more likely to be dusty or dirty. My car has a rubber gasket to 100% close off this area when you shut the hood.

I don't know if there is a best way to exhaust the engine compartment air, but many have dumped it out around the front tires. (This area is hardest to pan since the tires move, plus the air there is already turbulent.) If there is a gap between your pan and body all the way back, some of the air could travel there.

As for your fan clutch being bad, my advice is to get an electric fan and a temperature switch and install it. On a hot day in stop and go traffic is kind of the worst case scenario, as you aren't going fast enough to get a lot of air through your radiator, so the fan would provide some cheap insurance that your temperatures don't get excessive.

Last edited by aardvarcus; 06-04-2013 at 07:58 AM.. Reason: I can't spell.
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