Yote
Well-Known Member
Yote
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Functional twin hood scoops
- Thread starter Yote
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67dartgtgo
Well-Known Member
More pictures please....looks cool.
Yote
Well-Known Member
A couple more pics added to original post. If you want any specific pic or info. let me know what.
Yote
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Yote
Well-Known Member
Drove car on a club cruise last weekend. Really could not notice any appreciable difference but do not have any technical means to determine that. Maybe it will be like when I vacuum, wash and wax my car—- it just seems to run better then !!!
Yote
PS: I used existing holes in hood bracing to mount my modification without making any new ones. Didn’t want to adulterate the car any more than it already is.
Yote
PS: I used existing holes in hood bracing to mount my modification without making any new ones. Didn’t want to adulterate the car any more than it already is.
gzig5
Well-Known Member
"They" say that those scoops that are low to the hood like that are not very effective, same with E-body Rallye hoods. Six pack hoods suppose to be better because they get up into the air more. Supposedly too close to the boundary layer or whatever. I haven't tried, it but I will when I get to that point. If nothing else I don't think it hurts. But, if you drive in the rain you may want to think about how to let water out before it gets to the carb or add a door with cable actuation, like some of the original scoops had.
I love it!!! Any more info on the details of you install would be appreciated. The fact that it is all reversible is just the icing on the cake. As far as the scoop height goes - that applies to the ram effect of the scoop, but a system like this relies on the vacuum of the engine to pull colder denser air from outside (rather than hotter under hood air).
If you look at the 70 340 air cleaner the two intake air holes point right at the holes in the hood. It has long been speculated that Mopar was working on a set of 90 degree pieces that fit in the air cleaner and then had a foam top that the hood closed onto for a sealed system. If somebody could design something functional like that they would sell hundreds of pairs!
If you look at the 70 340 air cleaner the two intake air holes point right at the holes in the hood. It has long been speculated that Mopar was working on a set of 90 degree pieces that fit in the air cleaner and then had a foam top that the hood closed onto for a sealed system. If somebody could design something functional like that they would sell hundreds of pairs!
The A-body scoops are better at letting heat out of the engine compartment than introducing any significant volume of fresh air. As already stated, the first couple inches (ish) above the hood sit in a boundary layer for airflow. Even at speed there’s very little velocity to the air within that layer. Think like an eddy in a river. And the A-body scoops simply aren’t tall enough to get out of the boundary layer. So as a part of a ram air or even just a cold air intake they’re pretty much useless. They let some hot air out, they may introduce some air from outside but not any significant amount or with any velocity.
That’s why they raised the T/A hood scoop up off the hood. The exact height of the boundary layer depends on the specific aerodynamics of the car.
If you want a cold air intake, picking up air from behind the grille and routing it around the radiator and through the radiator support would be a better bet by far.
I have the A-body scoops on my Duster if it makes you feel any better, even drilled the holes and run the factory gaskets. But it takes more than a couple of holes to make them truly functional. The engine vacuum alone won’t be sufficient to pull air from much further out than the plenum you’ve created under the hood, and since it sits at the top of the engine compartment it’ll be the hottest part. The engine compartment sees air flow anyway, everything that goes through the grille goes into the engine compartment and then out under the car at speed. It’s why these cars with their large flat grilles tend to lift at speeds over 150mph. You can see Chryslers fix for it right on the Daytona’s, they reduced the frontal area and added downforce.
That’s why they raised the T/A hood scoop up off the hood. The exact height of the boundary layer depends on the specific aerodynamics of the car.
If you want a cold air intake, picking up air from behind the grille and routing it around the radiator and through the radiator support would be a better bet by far.
I have the A-body scoops on my Duster if it makes you feel any better, even drilled the holes and run the factory gaskets. But it takes more than a couple of holes to make them truly functional. The engine vacuum alone won’t be sufficient to pull air from much further out than the plenum you’ve created under the hood, and since it sits at the top of the engine compartment it’ll be the hottest part. The engine compartment sees air flow anyway, everything that goes through the grille goes into the engine compartment and then out under the car at speed. It’s why these cars with their large flat grilles tend to lift at speeds over 150mph. You can see Chryslers fix for it right on the Daytona’s, they reduced the frontal area and added downforce.
autopar3000
Well-Known Member
I was thinking about getting one of these Part #14x3@110 for my 70 Swinger, then running some hoses to the holes in the hood. Or maybe just a couple of plastic elbows, depending on the location. I would have to measure to figure out the best option.
Models of Ram Air Box
Models of Ram Air Box
The ram air box is a good one, but again, forget the hood source. Run the hoses straight to the radiator support and cut holes to feed them air directly from the front of the car. That would get you fresh air, traveling at speed. And since the air you’re picking up wouldn’t be going through the radiator it would just be forced down and under the car anyway.
Yote
Well-Known Member
From information I have found , IIRC (and we know that what is found on the internet is all true, lol)
1. Ram air effect is only good for 2-3 HP, unless driving at very high speed.
2. Cold air induction is supposed to be good for 8-12 HP. Also hood scoops are not much effective unless the bottom of the opening is at least 2” above the hood.
3. Supposedly cowl induction is better because of higher air pressure at that area. (The vent system on my car would make me believe that.)
My system draws all air through the scoops (except bypass leakage) and the underhood liner has somewhat a insulating factor. The hood ‘donuts’ being higher on top was supposed to be Mopar’s way of helping to keep rain water from entering.
Again this was done more for my entertainment and busy work than for any expectation of great results.
I appreciate all of the feedback.
MY INSTALL:
I used plastic ‘corrugated’ sign sheet for the bottom. After determining the approximate closed hood height , I put a small rubber hose with a dab of grease on the top, on the air cleaner threaded stem that would not fall down but slip easily. Closing the hood (gently) left a grease spot to determine the exact center of the air cleaner location.
The seal was made from open cell foam rubber adhered and sealed with clear silicone caulk. After assembly, I fastened it to the hood support braces (in existing holes) using plastic expanding rivets. I substituted metal #8 screws for the plastic ones. On the two central fasteners (one hidden under foam) I used longer screws with a piece of small rubber hose as a spacer.
I hope the pictures will explain the rest.
Yote
1. Ram air effect is only good for 2-3 HP, unless driving at very high speed.
2. Cold air induction is supposed to be good for 8-12 HP. Also hood scoops are not much effective unless the bottom of the opening is at least 2” above the hood.
3. Supposedly cowl induction is better because of higher air pressure at that area. (The vent system on my car would make me believe that.)
My system draws all air through the scoops (except bypass leakage) and the underhood liner has somewhat a insulating factor. The hood ‘donuts’ being higher on top was supposed to be Mopar’s way of helping to keep rain water from entering.
Again this was done more for my entertainment and busy work than for any expectation of great results.
I appreciate all of the feedback.
MY INSTALL:
I used plastic ‘corrugated’ sign sheet for the bottom. After determining the approximate closed hood height , I put a small rubber hose with a dab of grease on the top, on the air cleaner threaded stem that would not fall down but slip easily. Closing the hood (gently) left a grease spot to determine the exact center of the air cleaner location.
The seal was made from open cell foam rubber adhered and sealed with clear silicone caulk. After assembly, I fastened it to the hood support braces (in existing holes) using plastic expanding rivets. I substituted metal #8 screws for the plastic ones. On the two central fasteners (one hidden under foam) I used longer screws with a piece of small rubber hose as a spacer.
I hope the pictures will explain the rest.
Yote
Hey I like the idea, but from an aerodynamic standpoint it’s not going to accomplish much, if anything at all.
It’s a good looking install too! My only concern knowing the construction would be the temperature rating on that sign board plastic. Seems like it could be an excellent way to start an engine fire or shrink wrap your engine in plastic. Just a thought.
Yote
Well-Known Member
Those thoughts crossed my mind also. I have been checking the condition of it frequently. So far no sign of any deterioration from heat. Thanks.
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