Velocity Stacks and Scoops ???

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The Shocker

The Shocker

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Do Velocity stacks really do much? I know they look cool and Nostalgic ,which was the main reason i put one on my Dodge ,but has anyone ever dynoed a motor with and without one and seen a difference in power?I also added an old school redplexi scoop in an effort to try and get cooler air moving to the carb on the big end of the track .Does a scoop only work with a pan that seals it to the carb or does it matter ? I am gunna run my Dodge next month at a Nostalgia event and i am looking for anything i can find to help me in the hot weather .Car has been 11.81 at 113 with the mild 408 ,but i want 11.70's so bad i can taste it .Any thoughts or imput would be appreciated ,thanks...

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The benefit of the velocity stack is to both guide and smooth the airflow into the carb - less turbulence than having to climb up and over the top flange of carb. Check out most all engine dyno comparisons and you'll see a velocity stack used.
Of course you'll get a better result from the scoop if it's sealed to the carb since there's noplace else for the air to go except down the carb throat. The cooler outside air is also better since it's denser than hot underhood air. Doesn't matter where the cool outside air is coming from as long as it's coming from a high-pressure area like from a hoodscoop, front of car (radiator/headlight area - think Ford Thunderbolts), under the bumper with hoses (think Olds W-30 442), or base of windshield (think '67 Camaro Z28 or NASCAR airboxes).
Remember, you need a minimum of 30 sq. inches of scoop opening to get full benefit of an open scoop.
 
That is large enough to be considered an air horn. Which does the same thing.
about the hoodscoop. It will help a little when its not sealed.. But it will help a LOT (probably that tenth in the quarter) if you seal it.. In your case it should be fairly easy. just make a flat plate that has the center cut out the same size as your stack. then put foam rubber on the edges to get it sealed to the hood. But you might want to replace that piece you cut out of the rear hood reinforcement. just to make a simpler place to seal to. But I would say you could get into the 11.70's with just a sealed hood. because not only would you be getting cold air but also high pressure air. I don't remember what the correlation is but I think it is something like for every 10 degrees you lower the intake air temp you get a 10% increase in power. Or something like that.
 
Lots of good tips and helpfull people on this site.Thanks for the imput.Im gunna try and make me a pan to seal it to the scoop ...
 
Is there any sort of filter that can be fitted over the mouth of a velocity stack or bell chamber?

It seems to me that if you could guarantee filtered air, the bell chamber idea would be ideal for a street/strip car.....
 
Moparmal said:
Which would benefit more - a V/stack under hood, or a cold air pan?
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The cold air would benefit MORE because the amount of power an engine makes correlates with the difference of the intake and exhaust temps( to a certain extent) ... But like I said the best thing would be to just do both.
 
Seal it, and that will also pull the engine temp down; as that hood scoop is ruining the air flow through the radiator.
 
green1 said:
Seal it, and that will also pull the engine temp down; as that hood scoop is ruining the air flow through the radiator.
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Please explain how the scoop is killing air flow through the radiator ? I am running a big electric fan pushing from the front through the radiator .This is a hobbie ,drag only car that sees no street use.Im not arguing or disagreeing ,id just like to know what your talking about in technical terms ,for my own understanding ,thanks...
 
The Shocker said:
Please explain how the scoop is killing air flow through the radiator ? I am running a big electric fan pushing from the front through the radiator .This is a hobbie ,drag only car that sees no street use.Im not arguing or disagreeing ,id just like to know what your talking about in technical terms ,for my own understanding ,thanks...
Click to expand...

When your hood is regular the space in the engine bay is a negative pressure zone because the air gets sucked out through the bottom. The air in front of the radiator is a high pressure zone. Together they "suck" air through the radiator. if you don't seal the scoop you turn the engine bay to a High pressure zone and mess up the air flow.

Hope this helps,

Benjamin
 
bjkadron said:
When your hood is regular the space in the engine bay is a negative pressure zone because the air gets sucked out through the bottom. The air in front of the radiator is a high pressure zone. Together they "suck" air through the radiator. if you don't seal the scoop you turn the engine bay to a High pressure zone and mess up the air flow.

Hope this helps,

Benjamin
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I see what your saying now.Makes perfect sense ...
 
They look nasty thats why we quit using them in the late 80's.They only look decent when there are two side by side on top of a tunnel ram.But you don't see tunnel rams anymore either. Jim
 
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