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Discussion Starter #1
Me and my bro inlaw have been discusing the advantages and he was wondering whats the advantage of a colw?
The pro stocks run a scoop and go over 200 so why would i need a cowl scoop?
This is what i ran on my datsun,seem to work very well.
 

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A cowl hood is good for the street and racing. In pro stock cars they are forcing air into the engine. On the street you want to get the heat out of the engine bay. Pro stock cars do not run that long so they are not to worried about getting heat out. With a cowl hood on the street it serves 2 things. It lets the heat out as well as lets cooler air into the engine bay for the engine. This is all IMO though.
 

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I'm not a big fan of a scoop on the street and I am guessing a lot of cops aren't either. If you are running 200mph then get a scoop if not get a cowl hood. The cowl hood actually takes advantage of a low pressure area at the base of the winshield to help get air into the engine compartment. If you have a tall carb set up you might need a higher cowl hood. I started with a 2 inch on mine and now I run a tunnel ram and it still fits under a 4" cowl.
 

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Discussion Starter #4
Thanks that was all i need. You guys have made up my mind for me.Its cool to not have to think so much:yes:
 

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Plus, with the limited run time, they don't have to worry about sucking in rain, bugs, road debris, etc. A cowl hood eliminates all these issues on the street.
 

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how does a low pressure area work?
Cut and paste from another site

Cowl induction is a type of induction that increases the flow of low temperature air to an engine. A hood with a rear-facing scoop, usually located near the windshield, creates an area of low pressure which acts as a vacuum and sucks air into the engine. Since the air is being sucked in instead of forced in, both its density and temperature are lower.
 

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I thought lower density air was an undesireable thing, almost like negative psi?
I am guessing it's like density altitude or corrected altitude. If the density of the air is lower there is more air and less grains of water in the air thus making it like you are closer to sea level. If my car sees negative density altitude it acts totally different. There is a ton more horsepower and it starts doing stupid stuff like wheel stands.
 

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Maybe someone can chime in here because I thought hotter was less dense and made less power. Same thing with higher altitude ie less density less power.

So I'm trying to understand how a supply of less dense air can be a beneficial thing
 

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A cowl scoop is only going to be effective if it is a fuctioning scoop - air pan that seals to the underside of the scoop and around the carb/throttle body opening to take advantage of the high-pressure area at the base of the windshield, feeding cooler (cooler and more oxygen dense than the air surrounding the engine), denser air. If the scoop is not sealed to the carb, the only advantage of a cowl scoop is that it can clear a taller air cleaner or induction set up.
 

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Maybe someone can chime in here because I thought hotter was less dense and made less power. Same thing with higher altitude ie less density less power.

So I'm trying to understand how a supply of less dense air can be a beneficial thing
You are thinking about this backwards. When the car is at speed, there is a high pressure area at the base of the windshield. This high pressure (higher then the atmospheric at that altitude) is forced into the cowl because the pressure is lower inside the cowl then at the base of the windshield.
 

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You are thinking about this backwards. When the car is at speed, there is a high pressure area at the base of the windshield. This high pressure (higher then the atmospheric at that altitude) is forced into the cowl because the pressure is lower inside the cowl then at the base of the windshield.
that makes sense. but I think I have to agree with vin63 that its the cooler air from a sealed cowl and not the higher pressure that might make more power.
 

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Ok you guys have changed my mind, VIN63 Made me think of my dad he ran a car in grand nationals,(BACK IN THE DAY ) Nascar,and he built a air box around the air cleaner and stretched back to the windsheild inside the cowl.
It makes perfect sence.I do wonder how much it will help consistancy,cuz thats what im all about.That is what you are saying right vin63?
 

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Yep, the Cup cars run an air box/cleaner assembley that is fed from the cowl area of the car.

Here's a photo of my air pan that seals to the underside of my scoop. I run an air bell to help smooth the air flow into the carb. This is when I race...I run an air cleaner when I'm putzing around on the street to our get-togethers. :D

 

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that makes sense. but I think I have to agree with vin63 that its the cooler air from a sealed cowl and not the higher pressure that might make more power.
Absolutely. The cooler air is definitely the benefit. Thats just how the cowl gets to the cool air, using the high pressure area. I need to try sealing up my cowl hood with a cake pan and see if it makes any difference at the track on a hot day.

-Dan
 
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