Hood scoop performance ..
#2824301
09/23/20 08:51 PM
09/23/20 08:51 PM
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Joined: Feb 2004
Posts: 34,928 S.E. South Dakota !
bigdad
OP
Still Posting A Lot
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OP
Still Posting A Lot
Joined: Feb 2004
Posts: 34,928
S.E. South Dakota !
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Any data to back up any use .. or, just for looks
The lips of fools bring them strife, and their mouths invite a beating.Proverbs 18:6
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Re: Hood scoop performance ..
[Re: bigdad]
#2824407
09/24/20 05:10 AM
09/24/20 05:10 AM
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Joined: Jan 2003
Posts: 2,926 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,926
A shed in England
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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
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Re: Hood scoop performance ..
[Re: Dragula]
#2824412
09/24/20 06:04 AM
09/24/20 06:04 AM
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Joined: Jan 2003
Posts: 2,926 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,926
A shed in England
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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 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
'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
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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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Joined: Jan 2003
Posts: 2,926 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,926
A shed in England
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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. 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.
'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
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Re: Hood scoop performance ..
[Re: Tig]
#2824417
09/24/20 06:31 AM
09/24/20 06:31 AM
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Joined: Dec 2016
Posts: 1,113 Usa
A39Coronet
super stock
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super stock
Joined: Dec 2016
Posts: 1,113
Usa
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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. 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. 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.
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Re: Hood scoop performance ..
[Re: A39Coronet]
#2824424
09/24/20 06:56 AM
09/24/20 06:56 AM
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Joined: Jan 2003
Posts: 2,926 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,926
A shed in England
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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. 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. 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
'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
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Re: Hood scoop performance ..
[Re: A39Coronet]
#2824426
09/24/20 06:59 AM
09/24/20 06:59 AM
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Joined: Oct 2007
Posts: 4,209 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,209
New York
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it was picking up SIGNIFICANTLY more air than the engine needed
That's what a supercharger does.
Boffin Emeritus
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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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Joined: Jan 2003
Posts: 2,926 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,926
A shed in England
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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. 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
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Re: Hood scoop performance ..
[Re: Tig]
#2824446
09/24/20 09:00 AM
09/24/20 09:00 AM
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Joined: Nov 2006
Posts: 2,255 IL
furious70
top fuel
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top fuel
Joined: Nov 2006
Posts: 2,255
IL
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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.
70 Sport Fury 68 Charger 69 Coronet 72 RR
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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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Joined: Jan 2003
Posts: 2,926 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,926
A shed in England
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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
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Re: Hood scoop performance ..
[Re: Tig]
#2824542
09/24/20 12:41 PM
09/24/20 12:41 PM
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Joined: Jan 2003
Posts: 10,011 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,011
Frostbitefalls MN (Rocky&Bullw...
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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.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Hood scoop performance ..
[Re: Tig]
#2824550
09/24/20 12:49 PM
09/24/20 12:49 PM
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Joined: Jan 2003
Posts: 13,375 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,375
Marion, South Carolina [><]
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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.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: Hood scoop performance ..
[Re: Tig]
#2824607
09/24/20 03:12 PM
09/24/20 03:12 PM
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Joined: Dec 2003
Posts: 22,696 Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,696
Bitopia
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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. 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. 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 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.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: Hood scoop performance ..
[Re: bigdad]
#2824644
09/24/20 04:25 PM
09/24/20 04:25 PM
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Joined: May 2011
Posts: 4,489 northern,Ohio,USA
Clanton
master
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master
Joined: May 2011
Posts: 4,489
northern,Ohio,USA
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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] Any data to back up any use .. or, just for looks
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