carb air pan

Old 03-12-2011, 06:40 PM
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fast75vega
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Default carb air pan

never used one with my hood scoops.... will there be really a big difference if i add one?
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Old 03-12-2011, 07:32 PM
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zipper06
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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.
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Old 03-13-2011, 04:44 AM
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johnracer
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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
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Old 03-13-2011, 09:14 AM
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mopar1968
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I don't run one with my cowl hood :!:




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Old 03-13-2011, 09:24 AM
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fast75vega
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i have a cowl hood and a scoop hood for my vega.... car just seems in consistent... was thinking its not getting same amount of air each run? :?
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Old 03-13-2011, 09:33 AM
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mopar1968
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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 :!:



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Old 03-13-2011, 01:45 PM
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TheYellaBrick
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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
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Old 03-13-2011, 07:05 PM
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zipper06
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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
No it's .012 hundreds different. I ran 10.59 the previous run, i had dialed 10.60, and the other lane redlite so i ran it out. So i dialed 10.59 and ran 10.71, with no changes except no carb pan.

Zip.
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