carb air pan
03-12-2011, 06:32 PM
#2
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Join Date: Jan 2006
Location: La.
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They are good for tenth, with a front scoop, don't know how much with a cowl induction. They have to be worth something since every NASCAR car uses them. i lost a major event with a front scoop car when i got so busy the last round, i forgot to put the carb pan on. The car ran .012 slower than the previous pass and i was .011 off the dial, but equal on the tree.
Zip.
Zip.
03-13-2011, 03:44 AM
#3
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Join Date: Aug 2005
Location: Rifle Colorado
Posts: 585
Zip, that's only a hundreth.......
Difference, yes. Really big difference, no. The faster you are, the bigger the difference. When I went to an air pan years ago, my et and speed didn't change at all, but the car became more consistent......
Johnny
Difference, yes. Really big difference, no. The faster you are, the bigger the difference. When I went to an air pan years ago, my et and speed didn't change at all, but the car became more consistent......
Johnny
car just seems in consistent... was thinking its not getting same amount of air each run? :?
03-13-2011, 08:33 AM
#6
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Join Date: Dec 2006
Location: Abingdon,Virginia
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Cowl hood's are notorious for poor airflow when used with airpan. The air pan seal's the hood so airflow must come in from rear of hood :!: You must trim the airpan in the front in order to get proper airflow :!:
Mark
Mark
03-13-2011, 12:45 PM
#7
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Location: Emmett, Idaho
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Cowl INduction...opening is at a VERY HIGH pressure area at the base of the windshield. Air flow does NOT occur OUT of the cowl INduction scoop, it goes IN the scoop creating a high pressure area within the airpan sealed carb INtake space.
There can also be parasitic drag from the cooling air-flow through the radiator, past the engine package, and out the BOTTOM of the engine room. The higher the vehicle speed the greater the 'air flow dam' of engine room air trying to 'join' the under car airflow. Hence creating a low pressure vacuum UNDER the car via front air dam and side skirts GREATLY increases cooling air flow efficiency/cooling efficiency.( the reason there are mini air dams under the bumpers of pickups, vans, and most cars produced today) Any of THAT air that gets into the induction system will INCREASE the intake charge temperature through the air/fuel management system.
There can be a 20 degree ambient air temp difference from 1 inch off the pavement and 24 inches off the pavement, higher being cooler.
An interesting article about aerodynamic drag on different shapes;
http://insideracingtechnology.com/tech102drag.htm
There can also be parasitic drag from the cooling air-flow through the radiator, past the engine package, and out the BOTTOM of the engine room. The higher the vehicle speed the greater the 'air flow dam' of engine room air trying to 'join' the under car airflow. Hence creating a low pressure vacuum UNDER the car via front air dam and side skirts GREATLY increases cooling air flow efficiency/cooling efficiency.( the reason there are mini air dams under the bumpers of pickups, vans, and most cars produced today) Any of THAT air that gets into the induction system will INCREASE the intake charge temperature through the air/fuel management system.
There can be a 20 degree ambient air temp difference from 1 inch off the pavement and 24 inches off the pavement, higher being cooler.
An interesting article about aerodynamic drag on different shapes;
http://insideracingtechnology.com/tech102drag.htm
03-13-2011, 06:05 PM
#8
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Join Date: Jan 2006
Location: La.
Posts: 2,890
Originally Posted by johnracer
Zip, that's only a hundreth.......
Difference, yes. Really big difference, no. The faster you are, the bigger the difference. When I went to an air pan years ago, my et and speed didn't change at all, but the car became more consistent......
Johnny
Difference, yes. Really big difference, no. The faster you are, the bigger the difference. When I went to an air pan years ago, my et and speed didn't change at all, but the car became more consistent......
Johnny
Zip.
