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Hood scoop performance .. #2824301
09/23/20 08:51 PM
09/23/20 08:51 PM
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bigdad Offline OP
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Any data to back up any use .. or, just for looks


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Re: Hood scoop performance .. [Re: bigdad] #2824332
09/23/20 09:48 PM
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Depends on the scoop.


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Re: Hood scoop performance .. [Re: bigdad] #2824344
09/23/20 10:17 PM
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There is a lot of information on hood scoops that is out floating around. Most of it doesn't matter to the average bracket guy but if you're going faster than 150 mph it gets fairly critical. The shape of hood scoops in Pro Stock changed significantly over the years as they figured out what worked and what didn't.

Re: Hood scoop performance .. [Re: JERICOGTX] #2824347
09/23/20 10:23 PM
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When Warren Johnson was actively racing in PS, he was working with K&G on filters and scoops. The Pro Stock scoop of that time ate HP to make HP. Don't remember the numbers but it was something like it ate 35 to make 64. A velocity stack makes the most HP with its simpler technology. Straightens the air to give the carb a strong and consistent signal.

Re: Hood scoop performance .. [Re: bigdad] #2824407
09/24/20 05:10 AM
09/24/20 05:10 AM
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'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
Re: Hood scoop performance .. [Re: bigdad] #2824408
09/24/20 05:37 AM
09/24/20 05:37 AM
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As long as the carb is sealed to it, same ET...I switched from a cowl hood to a Six pack hood, same ET...Same MPH


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https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Hood scoop performance .. [Re: Dragula] #2824412
09/24/20 06:04 AM
09/24/20 06:04 AM
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Tig Offline
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Originally Posted by Dragula
As long as the carb is sealed to it, same ET...I switched from a cowl hood to a Six pack hood, same ET...Same MPH

Apologies for butting in on the OP but I don't think most 6 pak scoops are high enough to catch the clean air. We did pick up (slightly) by sealing the carb to the very large six pak scoop on ours though.
We've changed now to a flat hood and perspex scoop, now I'm a little worried about hi speed lean out (140+ terminals) to the point I've been considering using a boost referenced regulator and tapping a port into the scoop.
I have no real idea of what pressure will build up inside the scoop 'til I try it though
[Linked Image]


'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
Re: Hood scoop performance .. [Re: bigdad] #2824415
09/24/20 06:17 AM
09/24/20 06:17 AM
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The night my 67 lost the scoop going through the lights, I had to run the rest of the evening without it. The car picked up significantly. Did some math, and with the hemi scoop sealed to the carb it was picking up SIGNIFICANTLY more air than the engine needed and the pan wouldn't let it escape. Ran the rest of the career without a carb pan. I think most people who have scoops actually hurt themselves with the opening size.


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Re: Hood scoop performance .. [Re: A39Coronet] #2824416
09/24/20 06:26 AM
09/24/20 06:26 AM
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Tig Offline
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Originally Posted by A39Coronet
The night my 67 lost the scoop going through the lights, I had to run the rest of the evening without it. The car picked up significantly. Did some math, and with the hemi scoop sealed to the carb it was picking up SIGNIFICANTLY more air than the engine needed and the pan wouldn't let it escape. Ran the rest of the career without a carb pan. I think most people who have scoops actually hurt themselves with the opening size.

Being devils advocate here, but that says to me if you had jetted up, you would have gained some H/P, and this agrees with the info in the article I posted above. shruggy


'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
Re: Hood scoop performance .. [Re: Tig] #2824417
09/24/20 06:31 AM
09/24/20 06:31 AM
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Originally Posted by Tig
Originally Posted by A39Coronet
The night my 67 lost the scoop going through the lights, I had to run the rest of the evening without it. The car picked up significantly. Did some math, and with the hemi scoop sealed to the carb it was picking up SIGNIFICANTLY more air than the engine needed and the pan wouldn't let it escape. Ran the rest of the career without a carb pan. I think most people who have scoops actually hurt themselves with the opening size.

Being devils advocate here, but that says to me if you had jetted up, you would have gained some H/P, and this agrees with the info in the article I posted above. shruggy


Negative. The scoop was fiberglass and would pop up in the middle indicating it was full. It became a snow plow against incoming air, like trying to push an exercise ball down track at 125mph. The car picked up because it was less drag, not because it was fat and came into range with A/f.

You want to run the smallest scoop you can get away with to make sure there isn't negative, or excessively positive, pressure above the carb. Aerodynamics aren't our friends with these old bricks as it is.


Follow my G3 Hemi Barracuda build on Youtube
https://www.youtube.com/watch?v=XSDAWczXoZw&list=PLTus_wQu8POADHEeJNJp2nr4NMHEyB9EK

2015 Tri-State Stock Super Stock Champion
2017 Monster Mopar Pro Winner
2018 Monster Mopar No Box Winner
Re: Hood scoop performance .. [Re: A39Coronet] #2824424
09/24/20 06:56 AM
09/24/20 06:56 AM
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Tig Offline
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Originally Posted by A39Coronet
Originally Posted by Tig
Originally Posted by A39Coronet
The night my 67 lost the scoop going through the lights, I had to run the rest of the evening without it. The car picked up significantly. Did some math, and with the hemi scoop sealed to the carb it was picking up SIGNIFICANTLY more air than the engine needed and the pan wouldn't let it escape. Ran the rest of the career without a carb pan. I think most people who have scoops actually hurt themselves with the opening size.

Being devils advocate here, but that says to me if you had jetted up, you would have gained some H/P, and this agrees with the info in the article I posted above. shruggy


Negative. The scoop was fiberglass and would pop up in the middle indicating it was full. It became a snow plow against incoming air, like trying to push an exercise ball down track at 125mph. The car picked up because it was less drag, not because it was fat and came into range with A/f.

You want to run the smallest scoop you can get away with to make sure there isn't negative, or excessively positive, pressure above the carb. Aerodynamics aren't our friends with these old bricks as it is.


OK, this all makes sense. I have some data logging on the car but won't find out until next year if the new scoop picks up some. But if it does, I'll now be wondering if it's through aero or H/P laugh


'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
Re: Hood scoop performance .. [Re: A39Coronet] #2824426
09/24/20 06:59 AM
09/24/20 06:59 AM
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it was picking up SIGNIFICANTLY more air than the engine needed

That's what a supercharger does.


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Re: Hood scoop performance .. [Re: A/MP] #2824427
09/24/20 07:04 AM
09/24/20 07:04 AM
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Tig Offline
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Originally Posted by A/MP
When Warren Johnson was actively racing in PS, he was working with K&G on filters and scoops. The Pro Stock scoop of that time ate HP to make HP. Don't remember the numbers but it was something like it ate 35 to make 64. A velocity stack makes the most HP with its simpler technology. Straightens the air to give the carb a strong and consistent signal.


There's the trade off.


'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
Re: Hood scoop performance .. [Re: Tig] #2824446
09/24/20 09:00 AM
09/24/20 09:00 AM
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I'm interested in any experience on the ET loss for a scoop without HP gain - I'm trying to decide whether to keep the 6 pack scoop on my Coronet with the change to a turbocharged engine. I love the way the car looks with the scoop vs flat hood, but if I'm giving up tenths of ET pushing air that I'm not going to be gaining anything from I might feel different.

Would a 6 pack scoop be much worse than a prostock scoop in how much disturbance to aero it causes?


Last edited by furious70; 09/24/20 09:01 AM.

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Re: Hood scoop performance .. [Re: furious70] #2824480
09/24/20 10:18 AM
09/24/20 10:18 AM
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Tig Offline
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Originally Posted by furious70
Would a 6 pack scoop be much worse than a prostock scoop in how much disturbance to aero it causes?


I would guess it depends how high and how far forward they are placed. Most of the stock positioned ones ( 3" hi ? ) are apparently out of the clean air flow. I would think the difference would be negligible but I don't have any data to say one way or the other..


'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
Re: Hood scoop performance .. [Re: Tig] #2824542
09/24/20 12:41 PM
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I am going to be testing this weekend to fugure out why my car picked up 3.8 mph by not running the hood, which is seperate from the scoop. The fastest pass was without an aircleaner or hood. I hope to test a couple of combos of aircleaners.


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Re: Hood scoop performance .. [Re: Tig] #2824550
09/24/20 12:49 PM
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Not very scientific, but my results were interesting to me...
I had a six pack hood on my car years ago. Taller than the stock A12 scoops, but not real tall. It went a little over a tenth quicker and 1.5 mph faster w/ the carb sealed to the hood. It was trying to rip off the car at 120+ mph though.

I switched to the 5" cowl hood that was NOT sealed to the carb and the performance didn't change one bit. I expected it to slow a little not being sealed up, but it didn't. It gained weight too...the six pack was a lightweight lift-off hood and the cowl is a heavy bolt on.

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Re: Hood scoop performance .. [Re: Tig] #2824607
09/24/20 03:12 PM
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Originally Posted by Tig
Originally Posted by A39Coronet
Originally Posted by Tig
Originally Posted by A39Coronet
The night my 67 lost the scoop going through the lights, I had to run the rest of the evening without it. The car picked up significantly. Did some math, and with the hemi scoop sealed to the carb it was picking up SIGNIFICANTLY more air than the engine needed and the pan wouldn't let it escape. Ran the rest of the career without a carb pan. I think most people who have scoops actually hurt themselves with the opening size.

Being devils advocate here, but that says to me if you had jetted up, you would have gained some H/P, and this agrees with the info in the article I posted above. shruggy


Negative. The scoop was fiberglass and would pop up in the middle indicating it was full. It became a snow plow against incoming air, like trying to push an exercise ball down track at 125mph. The car picked up because it was less drag, not because it was fat and came into range with A/f.

You want to run the smallest scoop you can get away with to make sure there isn't negative, or excessively positive, pressure above the carb. Aerodynamics aren't our friends with these old bricks as it is.


OK, this all makes sense. I have some data logging on the car but won't find out until next year if the new scoop picks up some. But if it does, I'll now be wondering if it's through aero or H/P laugh


Not clear to me in the above example how we know the "Pop up" was from over pressure underneath vs a low pressure above the scoop sucking it up?

Last edited by jcc; 09/24/20 03:12 PM.

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Re: Hood scoop performance .. [Re: jcc] #2824617
09/24/20 03:28 PM
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Sealing the carb to the bottom of the hood does work. My brother ran his car without the sealing pan and it would blubber a little at the top end. Not bad, but you could tell something was amiss. Only when he installed the pan and foam to the bottom of the hood did it pull clean all the way thru.

the front of each car is so different that only a wind tunnel is really going to tell you what works I'd think. Cars with recessed grilles (E-bodies) have a ton of turbulence that builds up in front of the grill at speed. Guy here has a purple 70 Challenger with a glass hood and the front edge bows up a lot on the top end. Enough that I would be worried about the hood cracking eventually. How does a hood scoop function on a car like that where the air all around the nose is scrambled up?

Re: Hood scoop performance .. [Re: bigdad] #2824644
09/24/20 04:25 PM
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There was an old tech paper in NHRA magazine on Pro Stock hood scoops and hp gains[1% I believe at 200 mph]
Originally Posted by bigdad
Any data to back up any use .. or, just for looks


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