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Discussion Starter #1
Some of you may have seen my recent thread about how I just finished boxing in my radiator. It is sealed from the bottom and sides. I have been getting mixed thoughts regarding whether I need an air dam still and where it should be mounted.

From reading some old threads on corner-carvers, I learned that since the Mustang is a "bottom breather," sealing off the bottom of the radiator counter-acts the car's breathing...the air no longer travels up in front of the radiator (since it's now sealed) using the stock air dam.

I've also read that sealing the bottom allows the air to flow better through the front of the lower bumper opening, thus making it now a "front breather."

Now, my questions are:

1. will I need an airdam still?

2. Should the air dam be mounted to the radiator support (stock location)? I understand that this will reduce the air behind the radiator BUT from my understanding, it will not help draw air into the bumper's lower opening.

3. Should the air dam be mounted along the edge of the front bumper (somewhat like the Mach 1 chin spoiler)? My understanding of this method is to draw more air into the bumper's lower opening, since it is now a "front breather," but it will not reduce the air behind the radiator, making it less effective.

Does anyone have any input on this? I'd like to finish up this project with the last bit if it is necessary. Thanks!!!
 

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Not sure what you are building, but on a Fox, its still important to run the air dam in the stock location (the bigger the better), as the air dam creates a low pressure area so the air gets pulled through the radiator and then down out of the engine compartment (after the radiator) to help pull all that hot air put of the engine compartment too. The newer stangs has the air dams on the front bumpers due to more aerodynamic gains (and it still helps create that low pressure area in the engine compartment).
 

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Discussion Starter #3
Not sure what you are building, but on a Fox, its still important to run the air dam in the stock location (the bigger the better), as the air dam creates a low pressure area so the air gets pulled through the radiator and then down out of the engine compartment (after the radiator) to help pull all that hot air put of the engine compartment too. The newer stangs has the air dams on the front bumpers due to more aerodynamic gains (and it still helps create that low pressure area in the engine compartment).
I have a 98 cobra with a Saleen front bumper. Do you think I can create the low pressure area on my car if I mount the air dam on the front bumper?
 

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I checked out your other thread with your fab work. I would honestly say to take off the lower aluminum sheet and put the air dam back in the stock location. Whats more important than how you get air into the radiator is how air flows after the radiator. An extreme example of this would be spending all the time in the world boxing in the front of a rad, but putting a piece of sheet metal the size of the radiator right against the back side of the radiator. Obviously you wont have any flow through the radiator. It doesn't matter where the air is coming from in front of the radiator, you just need to make sure it goes through, and the stock air dam (or the one you had) does a good job of that. Thats why you see a lot of people put some type of heat extracting vent in their hoods. Hope this makes sense.
 

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Discussion Starter #5
I checked out your other thread with your fab work. I would honestly say to take off the lower aluminum sheet and put the air dam back in the stock location. Whats more important than how you get air into the radiator is how air flows after the radiator. An extreme example of this would be spending all the time in the world boxing in the front of a rad, but putting a piece of sheet metal the size of the radiator right against the back side of the radiator. Obviously you wont have any flow through the radiator. It doesn't matter where the air is coming from in front of the radiator, you just need to make sure it goes through, and the stock air dam (or the one you had) does a good job of that. Thats why you see a lot of people put some type of heat extracting vent in their hoods. Hope this makes sense.
Thanks for your input. After talking to other fellow track guys and reading some articles on how all these parts work together, I think I'm going to leave my radiator box as is and re-install the air dam under the radiator support.

From what I've read, this setup will be the most efficient:

The fully sealed/boxed-in radiator will provide the increased airflow through the front of the radiator, while the air dam at the radiator support will decrease the air pressure behind the radiator, allowing the hot air to flow out of the engine bay easier.

By removing the bottom seal of the radiator box, I'll get the same effect except the flow into the radiator will not be as efficient.
 

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You can run both if you want (chin on the bumper and the rad support) if you have the clearance. Post up some pics, sounds like you got a nice set-up
 

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Discussion Starter #7

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When I did the airdam, I took one off the 4th gen Fbody, trimmed it to fit, and just used self tapping screws to bolt it to the lower radiator support. End result is an airdam that's about two and a half times bigger than stock


 

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i would think if you have boxed your rad in you no longer need the factory air dam, plus doesnt that add to the lifting of the front end which you dont want, so i would think get rid of the factory air damn if fully boxed
 

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I made a 6" air dam and fastened it to the stock piece and it brought those temps right down on really hot days at the track. The mach1 chin spoiler blocks most of the factory dam so a wider one is needed.
 

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From an aerodynamic perspective, the air dam on the leading edge of the bumper is the most efficient at reducing drag and increasing downforce.

The reason the stock air dam is needed is because the path of least resistance on the stock setup would be underneath the radiator. The trade off is that you increase drag and front end lift, which is not desirable. In fact, I would argue that there is no reason to go to a larger air dam in the stock location unless you are having cooling issues.

By boxing the radiator in, you force the air flowing through the grille opening to flow through the radiator. Depending on your cooling system and power plant, you may need more cooling which would be best accomplished by increasing the size of your grille opening. For a track car, you want the opening as small as possible for the purposes of drag reduction and increased downforce, but still large enough to provide adequate cooling. This is the reason why people tape up their grilles, as tape is easily added or removed for changing weather conditions. A cold day means more tape, a hot day means less.

If you have the leading edge air dam (provided it is low enough to be effective) then having a second air dam behind it will do nothing but add weight. Additionally, having the air dam low reduces the amount of air underneath the car, which by default creates lower pressure behind the air dam through which the higher pressure engine bay air will escape and travel underneath the car. With a boxed in radiator, the air must travel through the radiator to enter the engine bay, where it will then exhaust underneath the car.

If you are having cooling issues with your boxed in radiator, I would submit that you either need more grille opening, or simply a better (as in, larger, higher volume, more efficient, or all of these things) cooling system.
 

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When I did the airdam, I took one off the 4th gen Fbody, trimmed it to fit, and just used self tapping screws to bolt it to the lower radiator support. End result is an airdam that's about two and a half times bigger than stock


Even though I've never had cooling issues I tried this on my Cobra and it dropped the temps on the freeway. I just built a new 347 for the car and haven't taken it to the track yet but since it's now making 500rwhp/500rwtq I wanted to see if it would be something I could add on track days just in case. However, it had a side effect on my car, it made it run rich and even spuddered on the freeway. I think what happened was it causes turbulent air through the MAF which is mounted inside the pass side fender due to having a Vortech S-trim. I removed it and the problem went away. The air deflector I used was off a Ranger that I cut down to the width of the core support. It's about 5 inches tall so I'm going to try cutting it down to about 2.5 inches and try it again.
 

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my plan:

box in rad
remove fact air dam
re-install oem hood with vents (heat extractor hood)
seal the hood on the sides and rear where hood meets fenders/cowl
remove fact windshield wiper cowl, install smooth piece of aluminum
install some kind of air dam on leading edge
install dual cooling fans with shroud
 

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install dual cooling fans with shroud
I'd be hesitant to put a huge shroud on a track car...the shroud is only useful at low speeds (generally < 35mph) where most street cars live....on track, I would think it would hinder airflow thru the radiator...but that's just my WAG :blam:
 

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I'd be hesitant to put a huge shroud on a track car...the shroud is only useful at low speeds (generally < 35mph) where most street cars live....on track, I would think it would hinder airflow thru the radiator...but that's just my WAG :blam:

i know, iam torn... i just have a single small cooling fan zip tied to the radiator and in stop and go traffic she will over heat, #### just idling in the driveway she will over heat...

should i just put another small fan on with no shroud?
 

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yes it does, i still drive it on the street. havnt gone to the track yet :/
 
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