Cowl Induction?
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,743
Likes: 37
From: Stockton Ca
Cowl Induction?
Forum: This subject has been touched on, but not tested? I think that we argee that the idea is sound, but how well can it be excuted seems to be the question.
What would be the instrument that would show a pressure increase in the wiper area at the base of the windshield?
It was remarked that if it created pressure in the vents at speed, it should create positive pressure in the induction? That sounds reasonable to me, but how much? We know nascar goes after every scrap of advantage, but what about bang for the buck?
I like the idea of the Ram Air Box, which would require a higher rise hood. Piped to the cowl area, with the vents blocked off to increase and pressure build up.
To test this swag, measure the pressure before and after blocking off side vents. It should increase w/speed. Then if there is a solid number on the pressure increase, if any. Couldn't it be reasonably extrapolated to a power increase?
Might as well get a temp sender in there as long as we are at it! lol
Or is this all BS that means nothing on a less than track car?
R
What would be the instrument that would show a pressure increase in the wiper area at the base of the windshield?
It was remarked that if it created pressure in the vents at speed, it should create positive pressure in the induction? That sounds reasonable to me, but how much? We know nascar goes after every scrap of advantage, but what about bang for the buck?
I like the idea of the Ram Air Box, which would require a higher rise hood. Piped to the cowl area, with the vents blocked off to increase and pressure build up.
To test this swag, measure the pressure before and after blocking off side vents. It should increase w/speed. Then if there is a solid number on the pressure increase, if any. Couldn't it be reasonably extrapolated to a power increase?
Might as well get a temp sender in there as long as we are at it! lol
Or is this all BS that means nothing on a less than track car?
R
Safety Car
Joined: Jan 2009
Posts: 3,736
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From: anchorage ak
On this forum and smokinvette(how do like my cold air induction) theres a guy, mike80 built a cowl insulator to go work with the l88 hood and carburator and did some testing with a wireless thermometer pretty interesting actually. I want to do something that way, but am waiting to put the magnacharger on first.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
I believe there is something to gain but probably nothing youd feel
Had sealed cowl induction on a few cars and then run an open element never noticed a difference. Maybe at higher speeds it may help for that "last little bit". Oh well looks cool anyway
Seriously with a flimsy type glass cowl hood over 60 or so could notice the hood flex some so maybe thats where it could help some. Who knows for sure
Had sealed cowl induction on a few cars and then run an open element never noticed a difference. Maybe at higher speeds it may help for that "last little bit". Oh well looks cool anyway
Seriously with a flimsy type glass cowl hood over 60 or so could notice the hood flex some so maybe thats where it could help some. Who knows for sure
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
It would take a plenum about the size of a pickup truck bed to turn the high-velocity, turbulent air into stagnant, above-atmospheric pressure air. Aerodynamic tricks can also do this. If your intake is getting air from an open environment under the hood, your real benefit will be pulling cooler, denser air from outside the hot engine compartment by isolating the intake from the hot underhood air. A very rough approximation of the benefit is about 1hp for every 10-degree temperature drop on a carbureted, non-feedback system. The benefit of a cowl system is you are picking up outside air from a higher pressure area without adding any significant aerodynamic load on the body from a protruding scoop.
Drifting
Joined: May 2005
Posts: 1,968
Likes: 44
From: East TN
On this forum and smokinvette(how do like my cold air induction) theres a guy, mike80 built a cowl insulator to go work with the l88 hood and carburator and did some testing with a wireless thermometer pretty interesting actually. I want to do something that way, but am waiting to put the magnacharger on first.
With the outside temperature 80 degrees, do you think an engine would run better with air going into the carb at 80 degrees or 160 degrees, or do you think it makes no difference? Personally, I have noticed a huge improvement in how my vette runs by pretty much cutting the air temperature going into the carburetor in half.
http://forums.corvetteforum.com/c3-t...80-hood-4.html
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,743
Likes: 37
From: Stockton Ca
Ram Air?
Here is something I found long ago.
According to the caculator, 100 mph is worth 1.1% power increase.
They ask for the absolute pressure?
I put in 28 in/hg, that is what I see in many tests.
Would that need to be changed?
http://wallaceracing.com/ram-air-calc.php
Any thoughts?
R
According to the caculator, 100 mph is worth 1.1% power increase.
They ask for the absolute pressure?
I put in 28 in/hg, that is what I see in many tests.
Would that need to be changed?
http://wallaceracing.com/ram-air-calc.php
Any thoughts?
R
Race Director
Joined: Jul 2001
Posts: 15,892
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Racer
Joined: Nov 2006
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From: Champaign Urbana IL
Heres what I did. I didn't do any testing, but the engine definitely runs smoother and the throttle response is a bit better. Even if there isn't a large pressure difference the fact that the air is cold was enough incentive to built the CIA for me.
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,743
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From: Stockton Ca
Excellent idea. I was thinking of something similar, but I'm concerned about the filters getting wet.
That is why I wanted to go w/ram Air Box, so the element would be better protected.
I would still like to get something in the cowl area to measure the pressure change, if there is any! lol
R
That is why I wanted to go w/ram Air Box, so the element would be better protected.
I would still like to get something in the cowl area to measure the pressure change, if there is any! lol
R
Le Mans Master
Joined: Apr 2007
Posts: 7,353
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From: Graceland in a Not Correctly Restored Stingray
You're inquiring about a magnahelic pressure differential gauge. Harder to use properly and quantify the data than they are to afford. And, no, you don't have to travel at extra-legal speeds for cowl induction to do its thing.
Racer
Joined: Feb 2013
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From: Clifton Virginia
KUDOS!
Race Director
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Burning Brakes
Joined: Oct 2011
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From: McDonough Georgia
Great job... I LIKE it!!!
Where did you get the plenum on the carb? Did you have to make it, or were you able to make a store bought one work?
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Wonder if you wrapped the aluminum if it would reduce heat further. KNow wrap looks cruddy and all just sayin-
Commander cant view your pic wouldlike to see it. 15 lbs is quite a bit
Commander cant view your pic wouldlike to see it. 15 lbs is quite a bit
Race Director
Joined: Jul 2001
Posts: 15,892
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Why can't I see any ducting that actually goes rearward to the cowl?