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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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Chicago Blackhawks
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hemicar1971 Offline
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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
Re: Hood scoop performance .. [Re: hemicar1971] #2827631
10/01/20 10:09 PM
10/01/20 10:09 PM
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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.

[Linked Image]


67 Barracuda street/bracket car 11.27-119
68 Dart 502 BB 8.70s-152
414 cid SB Dragster 7.65-174
Re: Hood scoop performance .. [Re: moparacer] #2827647
10/01/20 11:11 PM
10/01/20 11:11 PM
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Eagle, Idaho
Neil Offline
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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

Re: Hood scoop performance .. [Re: moparacer] #2827715
10/02/20 07:30 AM
10/02/20 07:30 AM
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A shed in England
Tig Online work
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Originally Posted by moparacer
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.

popcorn
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
Re: Hood scoop performance .. [Re: Tig] #2827745
10/02/20 09:02 AM
10/02/20 09:02 AM
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one bad fish Offline
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Re: Hood scoop performance .. [Re: one bad fish] #2827751
10/02/20 09:17 AM
10/02/20 09:17 AM
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My Dart has a six pack scoop on it, on the street I don't seal the carb to the hood and I run a air filter. At the strip I run it with no air filter, it's faster sealed to the hood than not.

IIRC Dom had some afr issues at high speed with his carb sealed to a six pack scoop, the general consensus was that air was stacking up or there was turbulence in the scoop. Drilling some holes in the back of the scoop fixed it.

Re: Hood scoop performance .. [Re: justinp61] #2827753
10/02/20 09:20 AM
10/02/20 09:20 AM
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one bad fish Offline
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it should always run better with a scoop sealed just got to play with jets

Re: Hood scoop performance .. [Re: bigdad] #2827775
10/02/20 10:10 AM
10/02/20 10:10 AM
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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

Re: Hood scoop performance .. [Re: one bad fish] #2827781
10/02/20 10:20 AM
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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
Re: Hood scoop performance .. [Re: moparacer] #2827792
10/02/20 10:46 AM
10/02/20 10:46 AM
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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
Re: Hood scoop performance .. [Re: moparacer] #2827799
10/02/20 11:04 AM
10/02/20 11:04 AM
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one bad fish Offline
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Originally Posted by moparacer


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

Re: Hood scoop performance .. [Re: one bad fish] #2827818
10/02/20 11:36 AM
10/02/20 11:36 AM
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East Coast
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The velocity stacks looks like the best answer. The aerodynamic drag should probably be minimal. The carb and/or stack is in the wind and getting cooled down. As by design, it straightens the air giving stronger and consistent signal(s) to the carb. The motor, as an air pump, will suck all the air it needs and should keep up with the air speed. I imagine that each combo would like a different height. I'd avoid the K&N filter that are sold some stacks. I think that Thumper was thinking about the velocity stack during several of our conversations. As a cab guy, he's got to have more insight on this issue.

Re: Hood scoop performance .. [Re: Since1822] #2827825
10/02/20 11:44 AM
10/02/20 11:44 AM
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W. Kentucky
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Originally Posted by Since1822
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.

Re: Hood scoop performance .. [Re: A/MP] #2827828
10/02/20 11:48 AM
10/02/20 11:48 AM
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On the run…
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F4C236EF-90D9-4CCD-91C2-2ABB6999B1F7.jpeg
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
Re: Hood scoop performance .. [Re: bigdad] #2827867
10/02/20 01:01 PM
10/02/20 01:01 PM
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New York
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"Excess air!"
Where can I buy some of that?


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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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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.....
Re: Hood scoop performance .. [Re: polyspheric] #2827900
10/02/20 02:04 PM
10/02/20 02:04 PM
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Bitopia
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Originally Posted by polyspheric
"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.
Re: Hood scoop performance .. [Re: jcc] #2827953
10/02/20 03:50 PM
10/02/20 03:50 PM
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fredericksburg,va
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Too hot also

Re: Hood scoop performance .. [Re: bigdad] #2827956
10/02/20 04:01 PM
10/02/20 04:01 PM
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New York
polyspheric Offline
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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
Re: Hood scoop performance .. [Re: BloFish] #2828150
10/03/20 12:21 AM
10/03/20 12:21 AM
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Originally Posted by BloFish
.




Have you did some before/after testing on this?

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