Hood scoop performance ..
#2824301
09/23/20 08:51 PM
09/23/20 08:51 PM
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Joined: Feb 2004
Posts: 34,912 S.E. South Dakota !
bigdad
OP
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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: 2,924 A shed in England
Tig
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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: 2,924 A shed in England
Tig
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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: 2,924 A shed in England
Tig
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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: 1,111 Usa
A39Coronet
super stock
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super stock
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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: 2,924 A shed in England
Tig
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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: 4,206 New York
polyspheric
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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: 2,924 A shed in England
Tig
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master
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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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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: 2,924 A shed in England
Tig
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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: 10,008 Frostbitefalls MN (Rocky&Bullw...
gregsdart
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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: 13,365 Marion, South Carolina [><]
an8sec70cuda
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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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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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Clanton
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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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Re: Hood scoop performance ..
[Re: polyspheric]
#2824664
09/24/20 05:09 PM
09/24/20 05:09 PM
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A39Coronet
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it was picking up SIGNIFICANTLY more air than the engine needed
That's what a supercharger does. Supercharger forces air into the intake, no amount of scoop is going to creat tangible boost in that way. Youre best bet is you're supplying ample air to the engine and not starving it. 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?
Because it occured at the CASS, which I believe was around 42 MPH. No chance, based on the shape of the car, there was enough negative pressure to break the scoop tie downs. A 5" WO67 scoop has a significantly more in^2 than even a pro stock hood. Sealing that scoop to the pan made no sense to me.
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Re: Hood scoop performance ..
[Re: A39Coronet]
#2824681
09/24/20 05:42 PM
09/24/20 05:42 PM
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Joined: Oct 2007
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polyspheric
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no amount of scoop is going to creat tangible boost in that way
200 mph = 2 psi boost
I saw no remark w/r/t the longer a car is at high speed, the smaller the intake needs to be. Those big scoops are needed for 0-100, not after.
Boffin Emeritus
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Re: Hood scoop performance ..
[Re: A39Coronet]
#2824683
09/24/20 05:49 PM
09/24/20 05:49 PM
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GomangoCuda
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I have seen a 68 SS/AH scoop that was narrowed and the bottom half of the opening was blocked off. I didn't talk to him about what he was going after and if it helped but I think he may have been asked not to bring it back.
In theory, there is no difference between theory and practice. In practice, there is.
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Re: Hood scoop performance ..
[Re: polyspheric]
#2824685
09/24/20 05:55 PM
09/24/20 05:55 PM
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A39Coronet
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super stock
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no amount of scoop is going to creat tangible boost in that way
200 mph = 2 psi boost
I saw no remark w/r/t the longer a car is at high speed, the smaller the intake needs to be. Those big scoops are needed for 0-100, not after. Like I said, no scoop is going to create tangible boost like a blower. Per Warren Johnson: “If you plug in the numbers, you’ll find an increase in inlet air pressure of .142 psi at 90 miles-per-hour. Standard atmospheric pressure is 14.7 psi, so this represents an increase of just under 1 percent. If the air/fuel ratio is adjusted to compensate for the increased pressure, there should be a corresponding 1-percent increase in horsepower. For a 1,200-horsepower Pro Stock engine, that’s a gain of 12 horsepower. Hood scoop pressurization increases dramatically at faster speeds: It’s 2 percent at approximately 130 miles-per-hour, and 3 percent at 158 miles-per-hour. At the magical 200 mile-per-hour mark, the theoretical pressure increase is .704 psi, or 4.8 percent. That equals 56 “free” horsepower. “Unfortunately in racing, just as in life, there is no free lunch. The penalty you pay for this increase in inlet air pressure is the extra aerodynamic drag produced by the hood scoop. A hood scoop is inherently dirty in terms of its aerodynamics. You can minimize the penalty with proper radii and contours, but you can’t get rid of it. And because the scoop has to be large enough to enclose the carburetors and intake manifold, you don’t have much latitude to change its physical dimensions and frontal area. “From all of my calculations, it’s a wash between the increased horsepower from the ram effect and the higher aerodynamic drag produced by the hood scoop. In other words, though we gain horsepower from the increased inlet pressure, we have to use all of that power just to push the hood scoop through the air.”
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Re: Hood scoop performance ..
[Re: A39Coronet]
#2824693
09/24/20 06:08 PM
09/24/20 06:08 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
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no amount of scoop is going to creat tangible boost in that way
200 mph = 2 psi boost
I saw no remark w/r/t the longer a car is at high speed, the smaller the intake needs to be. Those big scoops are needed for 0-100, not after. Like I said, no scoop is going to create tangible boost like a blower. Per Warren Johnson: “If you plug in the numbers, you’ll find an increase in inlet air pressure of .142 psi at 90 miles-per-hour. Standard atmospheric pressure is 14.7 psi, so this represents an increase of just under 1 percent. If the air/fuel ratio is adjusted to compensate for the increased pressure, there should be a corresponding 1-percent increase in horsepower. For a 1,200-horsepower Pro Stock engine, that’s a gain of 12 horsepower. Hood scoop pressurization increases dramatically at faster speeds: It’s 2 percent at approximately 130 miles-per-hour, and 3 percent at 158 miles-per-hour. At the magical 200 mile-per-hour mark, the theoretical pressure increase is .704 psi, or 4.8 percent. That equals 56 “free” horsepower. “Unfortunately in racing, just as in life, there is no free lunch. The penalty you pay for this increase in inlet air pressure is the extra aerodynamic drag produced by the hood scoop. A hood scoop is inherently dirty in terms of its aerodynamics. You can minimize the penalty with proper radii and contours, but you can’t get rid of it. And because the scoop has to be large enough to enclose the carburetors and intake manifold, you don’t have much latitude to change its physical dimensions and frontal area. “From all of my calculations, it’s a wash between the increased horsepower from the ram effect and the higher aerodynamic drag produced by the hood scoop. In other words, though we gain horsepower from the increased inlet pressure, we have to use all of that power just to push the hood scoop through the air.” And sadly for WJ, his performance calculations didn’t equate to real life MPH gains. Still today, the MPH is not where it should be for a Pro Stock car factoring in the average gains across the last decade before the scoops were eliminated. Plus, the cars look stupid with that flat hood, and since they aren’t any faster, bring back the hood scoop AND carbs.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: Hood scoop performance ..
[Re: madscientist]
#2824705
09/24/20 06:36 PM
09/24/20 06:36 PM
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Joined: Dec 2016
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A39Coronet
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And sadly for WJ, his performance calculations didn’t equate to real life MPH gains. Still today, the MPH is not where it should be for a Pro Stock car factoring in the average gains across the last decade before the scoops were eliminated. Plus, the cars look stupid with that flat hood, and since they aren’t any faster, bring back the hood scoop AND carbs.
That's probably a sign the decade before the switch was focused on things not induction related but rather ring packs, suspension, and transmissions. I'd imagine those items are all but optimized at this point. I get their reasons for the switch, those same reasons don't seem consistent with the rest of their program though. However that's another thread for another day.
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Re: Hood scoop performance ..
[Re: A39Coronet]
#2824761
09/24/20 09:39 PM
09/24/20 09:39 PM
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Joined: Dec 2005
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CMcAllister
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Easy enough to put a pressure sensor in the scoop.
On just about anything carbureted, the carbs will be thru the hood. Something has to cover them. Why not make it a sealed scoop which will (should) improve performance. If the cowl rear opening type of scoop was effective, I'm sure they would have been in use by the people who had the budget to test such things..
Attention needs to be paid to internal construction to make sure it is pressurized with a minimum of turbulence.
If the results don't match the theory, change the theory.
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Re: Hood scoop performance ..
[Re: CMcAllister]
#2824886
09/25/20 10:47 AM
09/25/20 10:47 AM
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Joined: Jan 2003
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hemicar1971
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On the 1965 Hemi Belvedere with a factory scoop it picked up two MPH placing the factory plate on the carbs sealing the carbs to the hood on the first pass with the plate. I know in 1972 John Petrie decided to copy his 65 car and put a cookie pan on his doms on the1972 Cuda and it picked up a few MPH and some ET. Next time out most people in Pro Stock started to copy him. The scoop was a Shoe box type old pro stock scoop. I would say some work and some do not. You have to experiment to see why some things work and some things do not.
1971 HEMI E BODY REGISTRY
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Re: Hood scoop performance ..
[Re: A39Coronet]
#2825029
09/25/20 03:36 PM
09/25/20 03:36 PM
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Joined: Dec 2003
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jcc
If you can't dazzle em with diamonds..
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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?
Because it occured at the CASS, which I believe was around 42 MPH. No chance, based on the shape of the car, there was enough negative pressure to break the scoop tie downs. A 5" WO67 scoop has a significantly more in^2 than even a pro stock hood. Sealing that scoop to the pan made no sense to me. The "CASS" reference is unclear to me also, and so you stating there was not enough low pressure above the hood/scoop to suck it upwards, but there was enough high pressure air inside the scoop to lift the hood up, the latter which I find nearly unbelievable.
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: jcc]
#2825043
09/25/20 04:09 PM
09/25/20 04:09 PM
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340man4ever
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I saw almost a tenth in the quarter mile on my high ten second big block Dart, 68 Hemi Dart scoop.....not sealed vs sealed....back to back passes....When I was engineering the seal set up for that scoop, my buddy assured me that I was wasting my time...He ate crow when it worked......Your results may vary....Test, Test, Test
Last edited by 340man4ever; 09/25/20 04:11 PM.
Curator at Adams County Speed Shop
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Re: Hood scoop performance ..
[Re: 340man4ever]
#2825103
09/25/20 06:55 PM
09/25/20 06:55 PM
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cudaman1969
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My 64 Maxwedge ran almost the same with a stock hood as with a sealed Six Pac type. Don’t know why they worked but the rage at that time (70s) where newspaper boxes. They just worked, especially on tunnel rams, just cut carb holes and and long rod to hold them on. Prerunner to the Jimmy Durante nose.
Last edited by cudaman1969; 09/25/20 06:57 PM.
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Re: Hood scoop performance ..
[Re: cudaman1969]
#2825117
09/25/20 07:50 PM
09/25/20 07:50 PM
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CMcAllister
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My 64 Maxwedge ran almost the same with a stock hood as with a sealed Six Pac type. Don’t know why they worked but the rage at that time (70s) where newspaper boxes. They just worked, especially on tunnel rams, just cut carb holes and and long rod to hold them on. Prerunner to the Jimmy Durante nose. They were simple with a minimum of fabrication, they were sealed and they were free.
If the results don't match the theory, change the theory.
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Re: Hood scoop performance ..
[Re: jcc]
#2825132
09/25/20 08:38 PM
09/25/20 08:38 PM
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super stock
Joined: Dec 2016
Posts: 1,111
Usa
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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?
Because it occured at the CASS, which I believe was around 42 MPH. No chance, based on the shape of the car, there was enough negative pressure to break the scoop tie downs. A 5" WO67 scoop has a significantly more in^2 than even a pro stock hood. Sealing that scoop to the pan made no sense to me. The "CASS" reference is unclear to me also, and so you stating there was not enough low pressure above the hood/scoop to suck it upwards, but there was enough high pressure air inside the scoop to lift the hood up, the latter which I find nearly unbelievable. Losing a scoop and a hood on two separate occasions renders it the opposite of unbelievable. Do the math, per the article, the scoop was too large and my car picked up without the carb sealed to the hood because the excess air captured by the scoop could escape instead of cause aerodynamic drag. I'm not telling anyone what scoop to run, I'm sharing my experience. That car won the 2017 TriState Stock/Superstock championship without a carb pan, along with a bunch of Mopar event wins. It worked.
Last edited by A39Coronet; 09/25/20 08:41 PM.
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Re: Hood scoop performance ..
[Re: cudaman1969]
#2825810
09/27/20 08:17 PM
09/27/20 08:17 PM
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Joined: Aug 2003
Posts: 43,204 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,204
Bend,OR USA
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Last edited by Cab_Burge; 09/27/20 08:18 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Hood scoop performance ..
[Re: Cab_Burge]
#2825926
09/28/20 08:29 AM
09/28/20 08:29 AM
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Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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About 60% more, varies roughly by the cube of the speed.
Boffin Emeritus
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Re: Hood scoop performance ..
[Re: polyspheric]
#2825989
09/28/20 11:47 AM
09/28/20 11:47 AM
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Joined: Mar 2003
Posts: 2,509 PA
moparacer
master
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master
Joined: Mar 2003
Posts: 2,509
PA
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I have a couple cars that picked up 1 tenth in the 1/8 and 1.5 tenths in the 1/4 making an air pan and sealing it to the 440 six pack hood.
They run 10.50-11.20 range.
Definitely worth the effort.
67 Barracuda street/bracket car 11.27-119 68 Dart 502 BB 8.70s-152 414 cid SB Dragster 7.65-174
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Re: Hood scoop performance ..
[Re: cudaman1969]
#2826048
09/28/20 02:03 PM
09/28/20 02:03 PM
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Joined: Jun 2014
Posts: 3,192 Md.
carnut68
master
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master
Joined: Jun 2014
Posts: 3,192
Md.
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My 64 Maxwedge ran almost the same with a stock hood as with a sealed Six Pac type. Don’t know why they worked but the rage at that time (70s) where newspaper boxes. They just worked, especially on tunnel rams, just cut carb holes and and long rod to hold them on. Prerunner to the Jimmy Durante nose. I still use a paper box.
America First!
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Re: Hood scoop performance ..
[Re: carnut68]
#2826685
09/29/20 10:41 PM
09/29/20 10:41 PM
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Joined: Jan 2003
Posts: 5,108 Chicago Blackhawks
hemicar1971
master
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master
Joined: Jan 2003
Posts: 5,108
Chicago Blackhawks
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Yes there is an aerodynamic factor is every car and 150 MPH things begin to happen with a lot of cars. The 1965 SSBA car is stable at 154. Another friend SS 1968 Barracuda with a big aluminum hemi ran 830 and did not fully complete the pass under total power because the air was getting under the car and making the nose super light and scary at 170 mph. The Barracuda races Hemi Shoot outs and Cam AM so making it slower was a good thing. The sealing to the hood has to be tested with every car and motor combination. Might work might not the answer with be in the Time Ticket. There will be a lot of pressure on the hood so it better be bolted down right and a strong hood.
1971 HEMI E BODY REGISTRY
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Re: Hood scoop performance ..
[Re: hemicar1971]
#2827631
10/01/20 10:09 PM
10/01/20 10:09 PM
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Joined: Mar 2003
Posts: 2,509 PA
moparacer
master
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master
Joined: Mar 2003
Posts: 2,509
PA
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I am going to fabricate a scoop for my car and will post the results when I run it next weekend. I have been running hoodless with a uni filter so I suspect it will pick me up several hundredths. Mocked one up in carboard today. To check left lane tree vision. If this works good I will fit a hood around it over the winter. Trying to get a 5.40 1/8 mile pass before year is out.
67 Barracuda street/bracket car 11.27-119 68 Dart 502 BB 8.70s-152 414 cid SB Dragster 7.65-174
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Re: Hood scoop performance ..
[Re: moparacer]
#2827647
10/01/20 11:11 PM
10/01/20 11:11 PM
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Joined: Jan 2003
Posts: 20,598 Eagle, Idaho
Neil
The Doctor is in.
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The Doctor is in.
Joined: Jan 2003
Posts: 20,598
Eagle, Idaho
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In an old issue of Mopar Collectors guide they did a feature on a white 68 hemi cuda race car and the owner cut about a 1" or so opening across the back of the hemi scoop to let some of the excess air escape. With it enclosed on all 3 sides the volume of air at the top end was pulling the hood scoop and hood apart at the front corners. For a real fast car this may be something to consider doing??? Here is the car that I'm talking about. https://www.dragracecentral.com/DRCStory.asp?ID=22155
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Re: Hood scoop performance ..
[Re: moparacer]
#2827715
10/02/20 07:30 AM
10/02/20 07:30 AM
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Joined: Jan 2003
Posts: 2,924 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,924
A shed in England
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I am going to fabricate a scoop for my car and will post the results when I run it next weekend. I have been running hoodless with a uni filter so I suspect it will pick me up several hundredths.
Mocked one up in carboard today. To check left lane tree vision. If this works good I will fit a hood around it over the winter. Trying to get a 5.40 1/8 mile pass before year is out. Edit, Thought about a clear perspex scoop ?
Last edited by Tig; 10/02/20 07:32 AM.
'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: one bad fish]
#2827781
10/02/20 10:20 AM
10/02/20 10:20 AM
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Joined: Mar 2003
Posts: 2,509 PA
moparacer
master
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master
Joined: Mar 2003
Posts: 2,509
PA
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I am considering running a cowl hood like that setup to smooth airflow up into the scoop if my setup works. Although not as tall as that one.
67 Barracuda street/bracket car 11.27-119 68 Dart 502 BB 8.70s-152 414 cid SB Dragster 7.65-174
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Re: Hood scoop performance ..
[Re: moparacer]
#2827792
10/02/20 10:46 AM
10/02/20 10:46 AM
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Joined: Jan 2003
Posts: 2,924 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,924
A shed in England
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There are a few posts about the perspex scoops on The Bullet, not many back to back tests but most claim 1 - 1.5 tenths and around 3 mph improvement. https://www.yellowbullet.com/threads/lexan-carb-scoop.567887/HTH's
'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: moparacer]
#2827799
10/02/20 11:04 AM
10/02/20 11:04 AM
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Joined: Jul 2008
Posts: 1,534 bronx n.y
one bad fish
pro stock
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pro stock
Joined: Jul 2008
Posts: 1,534
bronx n.y
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I am considering running a cowl hood like that setup to smooth airflow up into the scoop if my setup works. Although not as tall as that one. kool
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Re: Hood scoop performance ..
[Re: Since1822]
#2827825
10/02/20 11:44 AM
10/02/20 11:44 AM
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Joined: Oct 2003
Posts: 11,684 W. Kentucky
justinp61
I Live Here
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I Live Here
Joined: Oct 2003
Posts: 11,684
W. Kentucky
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A few weeks back I posted results regarding my hood. I have a 68 roadrunner with six pack hood on it. Victor intake and 2" super sucker put the dominator vent tubes about 3/8" away from the underside of the hood. During test and tune we took the hood off and replaced it with a 4" K&N air filter with x stream top, 14" diameter. We gained three tenths from the previous run. My hood is not sealed to carb, but do pay attention to how close the carb is to the underside of the hood. I went 11.52 with the hood and 11.20 with air cleaner and without hood. +3mph Have you tried the hood without the carb so close to it? My vent tubes are probably 3" from the roof of my scoop.
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Re: Hood scoop performance ..
[Re: A/MP]
#2827828
10/02/20 11:48 AM
10/02/20 11:48 AM
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Joined: Nov 2004
Posts: 16,483 On the run…
BloFish
I Live Here
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I Live Here
Joined: Nov 2004
Posts: 16,483
On the run…
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Last edited by BloFish; 10/02/20 11:52 AM.
It really doesn't matter whether you win or lose… as long as you look good doing it!
‘65 A100 ‘69 ‘Cuda ‘73 Vega GT ‘06 Mega Cab ‘14 Mercedes SLK
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Re: Hood scoop performance ..
[Re: bigdad]
#2827867
10/02/20 01:01 PM
10/02/20 01:01 PM
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Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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"Excess air!" Where can I buy some of that?
Boffin Emeritus
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Re: Hood scoop performance ..
[Re: justinp61]
#2827885
10/02/20 01:31 PM
10/02/20 01:31 PM
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Joined: Jul 2004
Posts: 19,317 State of confusion
Thumperdart
I Live Here
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I Live Here
Joined: Jul 2004
Posts: 19,317
State of confusion
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Yes sir and cutting 5 tear drop holes in the rear made the afr's more stable and solved some siphoning issues w/the bowl vents as well......
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
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Re: Hood scoop performance ..
[Re: polyspheric]
#2827900
10/02/20 02:04 PM
10/02/20 02:04 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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"Excess air!" Where can I buy some of that? It's right here in this thread, and free, but don't take to much it will blow you away.
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]
#2827956
10/02/20 04:01 PM
10/02/20 04:01 PM
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Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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I understand and agree with owners/builders reporting their own experiences. What I find fault with is the idea that if these events actually occurred (and we take your word for it) that witnessing the event gives you some special insight as to exactly what caused the effects: causation vs. coincidence is perhaps the largest single fallacy in analysis. Unfortunately, although I am not by nature a lazy person, there are simply too many non sequiturs, false conclusions, rationalizations, and "it stands to reason" assumptions for a comprehensive response. Those who would enjoy reading my opinion can PM me. Thanks.
Boffin Emeritus
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