How much does a hood scoop actually help?

-
MRGTX

MRGTX

Well-Known Member
Joined
Sep 24, 2007
Messages
2,198
Reaction score
728
Location
CT, USA
I'm not sure if this is better suited to one of the engine forums or not but I figure that it might fit here too.

I'm excited to get a fiberglass hood for my Dart to shave off another pretty good chunk of weight. So far, I like the looks of the lower profile "six pack" style hood offered by AAR Fiberglass... but I'm weighing my options on a few points before I take the plunge.

Obviously cool air is a huge help for an engine...but assuming that the car is moving and air is rushing into the engine bay, how much benefit is there to having a scoop? Is it something that you would actually notice? Would it show up on a timeslip?

If there are benefits, do you need to seal the air cleaner to the scoop to achieve these benefits?

Currently, I'm just not sure if I want to make my car look that aggressive. For the moment, I have a pretty mild small block (~300hp). I'd like to go for a stroker kit...some day but for now my car isn't exactly a rocket ship and big scoop seems almost "ricey." If the advantage offered by the scoop is small enough, I might just go for the flat hood and fly under the radar.

Of course, if it made a really significant difference or if it would be more important down the road (with bigger hp numbers) I'd be fine with it... :)

Thoughts/opinions are very welcome.
 
The carbs should be sealed to the hood scoop. No air rushing into the engine bay. There is a tenth or more available with a scoop. A lot will depend on power level of course.
 
While I think hood scoops look cool, some research might be needed.
I don’t know how far back from the front edge of the hood you need to be, but consider-5.9 98 Jeeps had vents in the hood that used the low pressure zone created by the front of the vehicle to draw hot air OUT of the engine compartment.
Definitely seal the carb to the hood, but do you get any benefit other than temperature? To get any ram or forced air effect, you might actually have to get up pretty high to get into a real air stream.
I’m considering making a ducted cowl air intake & keeping the flat hood.
 
Last edited:
The air grabber on my parents factory stock '71 383 auto Road Runner showed no measurable ET reduction. Always ran low 15's open or closed.

grabber.jpg
 
Cooler air charge is about the only benefit from a stockish scoop. In order to get ram air effect the scoop needs to be up in the air stream, a 6 pack scoop is not tall enough from my research. I would seal the cleaner to the underside of the hood.

Here is my solution to seal it. I ordered an 18" aluminum baking pan, cut the center out, riveted the cleaner base to the pan. Added a push-on bulb seal to the rim. Added a Wix 4" tall filter. Better than sucking in hot air.

20180817_004355.jpg
20180817_004506.jpg
20180817_083629.jpg
20180817_083638.jpg
20180817_083646.jpg
20180817_083840.jpg
20180817_083938.jpg
20180823_114844.jpg
 
I'm running a very healthy 360 in my A body. When I opened the hood scoop up I could tell it was lean in the top end. Could not jet it up enough so I went up to a 750 carb. Maybe it was lean before? I don't think so :) but I can tell you I like it.
 
threewood said:
Here is my solution to seal it. I ordered an 18" aluminum baking pan, cut the center out, riveted the cleaner base to the pan. Added a push-on bulb seal to the rim. Added a Wix 4" tall filter. Better than sucking in hot air.
Click to expand...
This is one awesome idea!!!
 
RogerRamRod said:
To get any ram or forced air effect, you might actually have to get up pretty high to get into a real air stream.
Click to expand...

I've always read that you need to get up 4-6" (or more) into the air before you start to see any "Ram Air" effects. It had to do with surface friction or something and there being a blanket of stagnant air over the surface. If you think about what you see in wind-tunnel pictures, the smoke trail they run always sits up off the surface a bit (see pic).

mercedes-amg-gt-coupe-wind-tunnel-testing.jpg
 
I agree with Threewood. A hood scoop works best if it is sealed.
In the Book "We were the Ramchargers". Tom Hoover stated that the Max Wedge and Hemi cars (64 & 65 not sealed back then) The hood scoops showed no performance advantage.BUT they did help cool the engine compartment.
Also cool air duct direct to the air filter housing has shown gains. For me as much as 4 tenths better than without.(Your improvements may vary) This setup cost a whole $10. Not pretty but it works.
IMG_0434.jpg
 
Darter6 said:
I agree with Threewood. A hood scoop works best if it is sealed.
In the Book "We were the Ramchargers". Tom Hoover stated that the Max Wedge and Hemi cars (64 & 65 not sealed back then) The hood scoops showed no performance advantage.BUT they did help cool the engine compartment.
Also cool air duct direct to the air filter housing has shown gains. For me as much as 4 tenths better than without.(Your improvements may vary) This setup cost a whole $10. Not pretty but it works.View attachment 1715225433
Click to expand...
4 tenths on a slant? I'm puttin 2 on mine, Whoo hooo. LOL.
 
mderoy340 said:
Ever wonder why your car runs better on a cool morning? Scoop or cold air duct works.
Click to expand...

Agree, same goes for racing at night, cool dense air. The dart sport/ demon snorkel is supposed to be a pretty good scoop. I read somewhere that one and the challenger TA were the best factory offerings. All that said dosnt having a dog house on the hood allways look and feel fast? Lol! I miss the six pack scoop I had on my 69 cuda and after going back to the stock hood I'm saying wtf, why didn't Chrysler put chrome inserts on the 69, like the 67-68, or the cool 68,69 darts? Anyways, scoops are cool on muscle cars.
 
threewood said:
Cooler air charge is about the only benefit from a stockish scoop. In order to get ram air effect the scoop needs to be up in the air stream, a 6 pack scoop is not tall enough from my research. I would seal the cleaner to the underside of the hood.

Here is my solution to seal it. I ordered an 18" aluminum baking pan, cut the center out, riveted the cleaner base to the pan. Added a push-on bulb seal to the rim. Added a Wix 4" tall filter. Better than sucking in hot air.
Click to expand...

Hellrats said:
This is one awesome idea!!!
Click to expand...

I want to add just a little to this discussion, and maybe just a slight difference in the aluminum pan idea. (which is what I am also doing)

I have a scoop about 3" tall with the opening about 2/3 toward the front of the hood and I can tell whoever wants to know that air does not get forced in when driving.
When I drive in the rain I get a couple of small water spots on top of my air cleaner cover, but that's about it and I have driven in rain so hard that you couldn't do over 25mph and see in time to stop for anything stopped in front of me.

Hot compartment air definitely is sucked out instead of cold air forced in.
(Plus it cools the compartment a little quicker when stopped)

That said, when I do the aluminum pan and seal it to the hood for the cold air intake effect I am going to add a 1/4 drain tube to the back of the pan and run it down the back of the block just in case.

If it's raining hard and I'm parked on a nose up incline I don't want water running in and pooling in the pan.
The 1/4 drain won't make much difference at all as far as intake charge temp goes, but it sure will make a difference if water does happen to get in.

SANY0008.JPG


headon.jpg
 
I'm pretty sure wind tunnel testing has proven that Mopar "A body" Demon/Dart Sport scoops, T/A scoops and the generic "snorkel" scoop are the most effective.
 
TrailBeast said:
I want to add just a little to this discussion, and maybe just a slight difference in the aluminum pan idea. (which is what I am also doing)

I have a scoop about 3" tall with the opening about 2/3 toward the front of the hood and I can tell whoever wants to know that air does not get forced in when driving.
When I drive in the rain I get a couple of small water spots on top of my air cleaner cover, but that's about it and I have driven in rain so hard that you couldn't do over 25mph and see in time to stop for anything stopped in front of me.

Hot compartment air definitely is sucked out instead of cold air forced in.
(Plus it cools the compartment a little quicker when stopped)

That said, when I do the aluminum pan and seal it to the hood for the cold air intake effect I am going to add a 1/4 drain tube to the back of the pan and run it down the back of the block just in case.

If it's raining hard and I'm parked on a nose up incline I don't want water running in and pooling in the pan.
The 1/4 drain won't make much difference at all as far as intake charge temp goes, but it sure will make a difference if water does happen to get in.

View attachment 1715225660

View attachment 1715225662
Click to expand...

Do like the 6 pack does. A drain on each side. I’ll have to check the size of the tubes that are in the AAR style set up I am doing but I think there generous in size, like a 1/2 inch.
 
YY1 said:
I'm pretty sure wind tunnel testing has proven that Mopar "A body" Demon/Dart Sport scoops, T/A scoops and the generic "snorkel" scoop are the most effective.
Click to expand...

Any memory of a source on this? It would be interesting reading.
Thanks!
 
You must log in or register to reply here.
-

Back
Top