Originally posted by DemonSVT:


Also the thinking behind why the weatherstripping is there is in correct.
For instance the air above the cowl is low pressure as well. Hence the entire idea for cowl induction hoods. If they wanted the engine bay sealed they'd weather strip the entire hood. The seal on the cowl is to stop rain from getting in. Even with it gone there still is the plastic channel the stops rain anyway.



I respectfully disagree, not only because my info comes from "the great" TH, but because the cowl is a high-pressure zone, and that's why cowl-induction (as well as cabin venting) works.

Quote:

When a moving gas like air is brought to a halt, there is an attendant rise in pressure (the kinetic energy is converted to static pressure).

Bernoulli's equation illustrates this:
P + (rho*V**2)/2 = constant
where:
P = air pressure
rho = air density
V = air velocity

When you decrease the air velocity, pressure must increase to keep the quantity
a constant.




The air flowing over the side edges of the hood would create a low-pressure condition at the seam, which would suck air out of the engine bay (Venturi effect). This contributes not only to cooler air, but lower pressure behind the radiator.

The fact that the rear "weather seal" also keeps water out is certainly a plus, but I seriously doubt that's its only function.

Best thing is to remove the hoodliner, but leave the seals in place.

Also, it may be true that your performance is improved, or that your 1/4 mile time is better, somehow, because of your mods. Frankly, I couldn't give a rat. If that's your only goal, then you're doing the right thing.

I'm not Chicken Little, saying your engine will explode if you do this. (Obviously not the case.) It may be that the overall effect is minimal, or that the cooling fan compensates, somewhat, by running more often. All I'm saying is that these simple foam pieces serve a purpose.

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More backup info:
http://www.hardcore50.com/Articles/georgeklass/TheBigWind.htm

Originally posted by George Klass:
The actual high pressure areas on the front of your car, the places where you can get increased or high speed airflow, are typically at the front part of the hood (not the middle of the hood like the old Pontiac Firebird or Mach I shaker scoop) and the area where the rear of the hood meets the windshield (cowl area). The cowl is the area where your fresh air or vent inlets are located from the factory, and it�s not an accident.








Last edited by RogerB; 06/15/05 02:01 PM.
Function before fashion. '96 Contour SE "Toss the Contour into a corner, and it's as easy to catch as a softball thrown by a preschooler." -Edmunds, 1998