Running scoops backwards. [Archive]

Jetboatguru

10-06-2003, 09:10 AM

I will see if I can explain this:
By running the scoop backwards you are creating a diapezius air flow contiguom. The air needs help being directed through the carburetor bearings and the forastic pressure created by the scoop facing backwards helps build a quadramanetic stream of hyperdynesis air. This all equals a xylohyperkenises of better quality air that transpondifies through the motor.
Hope this helps.
idea idea

Sangster

10-06-2003, 09:12 AM

Couldn't have said it better Myself.. smile_sp

Moneypitt

10-06-2003, 09:24 AM

Just exactly WHAT did he say????? That only works with chrome bearings in the baffles!!!!..Moneypitt

Moneypitt

10-06-2003, 09:24 AM

Just exactly WHAT did he say????? That only works with chrome bearings in the baffles!!!!..Moneypitt

BigBoyToys

10-06-2003, 09:25 AM

Jetboatguru:
I will see if I can explain this:
By running the scoop backwards you are creating a diapezius air flow contiguom. The air needs help being directed through the carburetor bearings and the forastic pressure created by the scoop facing backwards helps build a quadramanetic stream of hyperdynesis air. This all equals a xylohyperkenises of better quality air that transpondifies through the motor.
Hope this helps.
idea idea WOW!!! Maybe that's what I'm doing wrong! eek! I have to run out and try that....I bet if I turn my scoop backwards I can get this tugboat to actually get on plane! wink :D

T-Bag

10-06-2003, 09:54 AM

Jetboatguru:
I will see if I can explain this:
By running the scoop backwards you are creating a diapezius air flow contiguom. The air needs help being directed through the carburetor bearings and the forastic pressure created by the scoop facing backwards helps build a quadramanetic stream of hyperdynesis air. This all equals a xylohyperkenises of better quality air that transpondifies through the motor.
Hope this helps.
idea idea These here words ain't in no mullet dictionary could you all definete those words.

Her454

10-06-2003, 09:58 AM

T-Bag:
These here words ain't in no mullet dictionary could you all definete those words. .....Its in there T-Bag, just look it up under "Bullshit". :) :) :) :)

Blown 472

10-06-2003, 10:05 AM

Her454:
T-Bag:
These here words ain't in no mullet dictionary could you all definete those words. .....Its in there T-Bag, just look it up under "Bullshit". :) :) :) :) :D :D :D :D

BigBoyToys

10-06-2003, 10:06 AM

T-Bag, no answer on phone....check your PM's :)

dmontzsta

10-06-2003, 10:08 AM

I think the only ones that make sense are skeepwerkzaz and superdave's. Jetboat that is some good BS'ing. :)
It seems to me running it backwards is going to starve the engine for air, not much air will shoot in through the back of the scoop, the air is going to pass right around the scoop. ??? boxed

FlatStupid

10-06-2003, 10:41 AM

I have a Xylohyprkenises meter that is avaliable for rent. It allows you to check the aforementioned air quality! Contact me the rent is reasonable. :D :D
[ October 06, 2003, 11:42 AM: Message edited by: Flat Stupid ]

Sangerboy

10-06-2003, 12:35 PM

Just having the scoop facing forward does not guarantee improved performance. I think Moneypitt posted in another thread about cross-section and airflow potential. Unless the scoop and base are designed for the increased airflow and pressure from a forward facing scoop it can actually increase air turbulance inside the scoop and decrease airflow through the carbs. At CFW on Father's day I turned 600 more rpm's with the scoop facing backward than with it facing forward. ( It's a Dooley scoop over twin 1050's)

DansBlown73Nordic

10-06-2003, 01:28 PM

idea I always thought the scoops were turned around to stop birds or large bugs from being thrown into the motor well riding on the trailer..... :D

Rexone

10-06-2003, 04:41 PM

For improved performance backing up around docks

CALIFORNIA PERFORMANCE

10-06-2003, 04:44 PM

GOOD ONE REX :D I like that. :D

superdave013

10-06-2003, 05:01 PM

Rexone:
For improved performance backing up around docks So you're sayin that your schiada runs strong in reverse hu :D

V-DRIVE VIDEO

10-06-2003, 05:06 PM

[QUOTE]Originally posted by Sangerboy:
[QB] Just having the scoop facing forward does not guarantee improved performance... I turned 600 more rpm's with the scoop facing backward than with it facing forward.
You see this Billy??? :D Why risk the washdown when facing backwards is faster anyway. :cool:
This proves it. :p ha ha ha

Rexone

10-06-2003, 05:07 PM

superdave013:
Rexone:
For improved performance backing up around docks So you're sayin that your schiada runs strong in reverse hu :D Extremely strong Dave. Never been beat backing away from the dock yet. :rolleyes: Those rollers coming over the transom are a bit of a bitch though.

HP350SC

10-06-2003, 05:14 PM

dmontzsta:
I dont understand why people do this. Can you guys help me understand? I turned mine around because back seat riders said intake noise hurt their ears.Lots quieter now-can hear exhaust only.No change in speed either.

DUCKY

10-06-2003, 05:50 PM

An engine is simply and air pump anyways. The engine will pull it's required amount of air whether the scoop is facing forward or backwards provided there is no restriction. With it forward, unless you are reaching enough speed to create turbulence (previously mentioned) or going fast enough to create a ram effect, which I don't think anyone here is. I think the magic number is about 160mph to create a ram effect. So running it backwards is good because, you don't worry about taking in water, and you make the make the cops happy.

Lookin for Liquid

10-06-2003, 06:24 PM

Just curious how you came up with the 160 mph number?

Moneypitt

10-06-2003, 06:32 PM

There is also the airflow around the hull to contend with.. I think George at finishline mentioned something like three feet above the drivers head in order to actually get any ram effect....Moneypitt

MikeF

10-06-2003, 07:30 PM

It is for those who know they'll be running in 2nd, 3rd, 4th and 5th position going into the first turn! :p

dude smith

10-06-2003, 07:38 PM

remember the 1970 super sport chevelle with cowlinduction hood it was the vacuum operated damper that opened up and used the airflow off the windshield that to increase the airflow into carb. try it both ways and check performance like mentioned above. if looks matter run it forward it just does'nt look right backwards. remember opionions are like .......well you know the rest.

H2OT PURSUIT

10-06-2003, 09:07 PM

dude smith:
remember the 1970 super sport chevelle with cowlinduction hood it was the vacuum operated damper that opened up and used the airflow off the windshield that to increase the airflow into carb. try it both ways and check performance like mentioned above. if looks matter run it forward it just does'nt look right backwards. remember opionions are like .......well you know the rest. So, if you run your scoop backwards and then mount a piece of sheet metal just behind it and angle it up and back at a 45 degree angle, like the Chevelle windshield, it too would have a high pressure area build up in front of the sheet metal and force air into the scoop just like a cowl induction hood. Why don't one of you high dollar go fast guys give it a try? It just might give you that 1/1000th of a second that wins the race. Just don't forget where the idea came from cause I'm just about out of Bud. I think I'll print this post so I have proof when it's time to patent this puppy. Yea right. It could happen.

Stab-n-Steer

10-07-2003, 07:37 AM

dmontzsta:
I dont understand why people do this. Can you guys help me understand? The scoop direction is determined by the motor placement. If the motor is mounted backwards (flywheel forward) the scoop points backwards. If the motor is mounted flywheel to the rear, the scoop points forward... Simple wink
S&S

CircleJerk

10-07-2003, 09:14 AM

MikeF:
It is for those who know they'll be running in 2nd, 3rd, 4th and 5th position going into the first turn! :p ExAcTlY Mr. F! You're sooooo correct! smile_sp

FlatRacer

10-07-2003, 01:54 PM

I'd love to see some hard data on whether it has an effect or not.
As a circle racer who has had my motor locked up after getting hosed down by another boat, I've run a scoop backwards out of fear of it happening again. I always thought I was putting myself at a disadvantage by doing this.
Now, I hear it has no effect, or can even have a positive effect??????
I want to know more!
FR :p

uclahater

10-07-2003, 03:27 PM

MikeF:
It is for those who know they'll be running in 2nd, 3rd, 4th and 5th position going into the first turn! :p smile_sp smile_sp smile_sp

Sangster

10-07-2003, 04:01 PM

Stab-n-Steer:
dmontzsta:
I dont understand why people do this. Can you guys help me understand? The scoop direction is determined by the motor placement. If the motor is mounted backwards (flywheel forward) the scoop points backwards. If the motor is mounted flywheel to the rear, the scoop points forward... Simple wink
S&S http://www.***boat.com/image_center/data/500/118cf8-med.jpg

1980SANGERV-DRIVE

10-08-2003, 05:00 AM

on lake boats that are not running a spark arrestor have to run them backwards by law in case of backfire through carb. so the fire does not go towards the passengers, otherwise with the sparkarrestor you can run them forward. My h20's worth. at least that is what I was told by the lake patrol. pig_flyi

Stab-n-Steer

10-08-2003, 06:24 AM

Sangster,
Are you trying to tell me a picture is worth a thousand words? :confused: Or is this case TWO words! :D
S&S

Cs19

10-08-2003, 02:32 PM

Im calling bs on the 160 mph "ram air affect" i would think even a 100 mph breeze would help out some.Check out how this guy had to put this piece of aluminum in front of his air cleaner to keep the fuel in the front carb.***notice the 3 carbs*** :D He runs in the 120s.
http://www.***boat.com/image_center/data/500/795Zell_Motor.jpg

rrrr

10-08-2003, 06:26 PM

IIRC, in our Indy car at 200 MPH or so the inlet pressure in the airbox is around three in. Hg. higher than ambient atmospheric pressure of 29.92 in. Hg..
That converts to about 1.3 lbs. of boost.
You gotta be moving to make a ram effect work.

Brodie

10-08-2003, 10:55 PM

cs19:
Im calling bs on the 160 mph "ram air affect" i would think even a 100 mph breeze would help out some.Check out how this guy had to put this piece of aluminum in front of his air cleaner to keep the fuel in the front carb.***notice the 3 carbs*** :D He runs in the 120s.
http://www.***boat.com/image_center/data/500/795Zell_Motor.jpg that terr looks like a jet
aint no jets runnin `120s cept those alky boats at ming

Sangerboy

10-09-2003, 04:52 AM

Brodie:
that terr looks like a jet
aint no jets runnin `120s cept those alky boats at ming [/b][/QUOTE]
My guess is that it is an outdrive on some sort of air entrapment hull

Jetboatguru

10-09-2003, 10:56 AM

rrrr:
IIRC, in our Indy car at 200 MPH or so the inlet pressure in the airbox is around three in. Hg. higher than ambient atmospheric pressure of 29.92 in. Hg..
That converts to about 1.3 lbs. of boost.
You gotta be moving to make a ram effect work. That is exactly what I was thinking.
You have to take the HG. and divide it by the copezius quotient. This coupled with hypoforganic sporaform gives you the ram effect.
I always thought the ram effect was slammin her behind.

Cs19

10-09-2003, 11:35 AM

Brodie,thats not a jetboat :D and yes it runs in the 120s. Second, that comment about jets not running in the 120s unless on alcohol is false, guys are running 120-130+ with naturally aspirated motors on gas without nos in the brackets and very consistantly too. :D

Jetboatguru

10-09-2003, 11:55 AM

cs19:
guys are running 120-130+ with naturally aspirated motors on gas without nos in the brackets and very consistantly too. :D Besides Hicks, name 2

Brodie

10-09-2003, 12:34 PM

Jetboatguru:
cs19:
guys are running 120-130+ with naturally aspirated motors on gas without nos in the brackets and very consistantly too. :D Besides Hicks, name 2 Dang. guru called you out. ouch

Blown 472

10-09-2003, 12:40 PM

I heard Hicks runs 135 on the bottle.
[ October 09, 2003, 01:40 PM: Message edited by: Blown 472 ]

Jetboatguru

10-09-2003, 12:53 PM

True Dat Blown, Hicks will run 125-135 off the bottle as well.
I am still waiting to see the other 2
:D :D

Cs19

10-09-2003, 01:09 PM

ill name 5 off the top of my head.All run 120 mph on naturally aspirated motors.
Joe lakamp,harold traylor,zellmers risky business,mike miller's bottle rocket,sunday showdown.Let me know if you need more. :D

Jetboatguru

10-09-2003, 01:20 PM

Risky Biz is no more
Traylor will run 115-120
Sunday Showdown will run mid 120's
Joe Lakamp will run 115
Mike Millers boat will run low 120 off the bottle.
So congratulations you named 2 others!
Not exactly a bumper crop of Naturally aspirated jets running 120-130.
So you have 2 jetboats running these numbers both with High dollar Oldsmobiles to do.

Jetboatguru

10-09-2003, 01:28 PM

Add Burrows to that list. He runs very stout but again another High dollar Olds.

Cs19

10-09-2003, 01:39 PM

Jetboatguru:
Risky Biz is no more
Traylor will run 115-120
Sunday Showdown will run mid 120's
Joe Lakamp will run 115
Mike Millers boat will run low 120 off the bottle.
So congratulations you named 2 others!
Not exactly a bumper crop of Naturally aspirated jets running 120-130.
So you have 2 jetboats running these numbers both with High dollar Oldsmobiles to do. Guru, are you not satisfied? Why not? Ya hicks is top dawg.We all know that. Risky biz was there and still holds the record, and it can be done again,its not like you could not build another one. traylor runs 120 thats what you wanted to see.Lakamp has run over 120, i was there, and he definatly ran harder than that at S.I.T.C... sunday showdown, 120 plus and bottle rocket is 120 plus plus. you asked for jets running there and i gave you 5. Sound like more than 2 and there are plenty more running there.
I bet the black mamba could run up there,head over heels?mike fiocco? stretch limo..what about all those guys that ran in arkansas a few weekends ago. very FAST jets out there.

Cs19

10-09-2003, 02:02 PM

High dollar or not,thats not the subject here.120-130 is acheivable in a naturally aspirated motor in a tunnell hull jet on gas,thats all im saying.On another note,I do not think some of these guys have half the hardware risy biz was running and they still manage to run very fast.. :D

DUCKY

10-09-2003, 02:17 PM

rrrr:
IIRC, in our Indy car at 200 MPH or so the inlet pressure in the airbox is around three in. Hg. higher than ambient atmospheric pressure of 29.92 in. Hg..
That converts to about 1.3 lbs. of boost.
You gotta be moving to make a ram effect work. That's where I got it from. A drag racer once told me that it takes about 160mph before you can actually build pressure from forward motion. In that picture above with the air shield around the front carb, he was reaching enough speed to create turbulance, and a low pressure (vacuum) area behind the front carb that would literally pull the fuel out of the bowls through the vents.

Jetboatguru

10-09-2003, 02:17 PM

I am "never satisfied" :D :D
That might be the name of my next boat
Are you going to make it out to Ming next weekend? If so, some by and say hello.
JBG

Cs19

10-09-2003, 02:31 PM

Im going to do my best to make it out there. I will definatly stop by and say hello if i make it out. That is if I can get myself to hang out in a flatbottom pit. :D J/K. i will see you there. good luck...cs19

Mike Oxbig

10-09-2003, 04:35 PM

" jawdrop jawdrop Once you go flat, you never go back" jawdrop jawdrop

EricU

10-09-2003, 05:12 PM

The scoop is backwards to keep your piece of shit friends cigeratte butts out of the engine, not to mention crushed empty beer cans.
Eric.

jaminj947

10-09-2003, 07:09 PM

LVjetboy

10-11-2003, 11:58 AM

Originally posted by rrrr:
IIRC, in our Indy car at 200 MPH or so the inlet pressure in the airbox is around three in. Hg. higher than ambient atmospheric pressure of 29.92 in. Hg..
That converts to about 1.3 lbs. of boost.
You gotta be moving to make a ram effect work.
So what was the airbox pressure at 50 mph or 100 mph? Box pressure doesn't have to be positive or higher than ambient for there to be a "ram" effect.
jer

Rexone

10-12-2003, 04:30 AM

oh shit here we go with the pressure thing again :D

LVjetboy

10-12-2003, 11:58 AM

Either that or it's back to the soccer mom vettes.
:)

Thunderbutt

10-12-2003, 01:17 PM

Jetboatguru:
I am "never satisfied" :D :D
That might be the name of my next boat
Are you going to make it out to Ming next weekend? If so, some by and say hello.
JBG Ron Carter's Stevens was named " NeverSatisfeid in the 60's. Good name.
I used to turn my scoop backwards when women are in the back seat, keeps there hair out of the carbs.

Racing Ray

10-12-2003, 05:15 PM

The air pump will indeed pull only what it needs to operate. You can put so much air into a scoop the engine can not use it and drag fuel out of the carb if the back is not closed. Seen this at the drags many times.
A careful look into a Pro Stock scoop can be interesting. Designed not to create positive air pressure but a neutral pressure zone so the engine pulls what it needs with an unlimited supply.

FlatStupid

10-12-2003, 06:17 PM

LVjetboy:
Originally posted by rrrr:
IIRC, in our Indy car at 200 MPH or so the inlet pressure in the airbox is around three in. Hg. higher than ambient atmospheric pressure of 29.92 in. Hg..
That converts to about 1.3 lbs. of boost.
You gotta be moving to make a ram effect work.
So what was the airbox pressure at 50 mph or 100 mph? Box pressure doesn't have to be positive or higher than ambient for there to be a "ram" effect.
jer Come on Jer really???? :confused:

rrrr

10-12-2003, 10:56 PM

Racing Ray:
The air pump will indeed pull only what it needs to operate. You can put so much air into a scoop the engine can not use it and drag fuel out of the carb if the back is not closed. Seen this at the drags many times.
There ya go. Many times I have been asked about this or that performance piece, and the answer is simple.... An engine is an air pump, and the only way to make more power is to move more air. Adding more fuel is a no brainer.
I talked to our Honda engineer about this thread yesterday (our car is powered by Honda), and he made some interesting comments. My earlier figures were off a bit, the gain is closer to 1" Hg., or about .65 PSI.
He observed that the drag from the airbox opening was prolly a larger penalty than the HP gain, and added that the spillover (absence of flow into the scoop) when the throttle was closed made the car looser in the turn and therefore the whole airbox thing was a net negative in his opinion.

LVjetboy

10-12-2003, 11:53 PM

Come on Jer really???? Sure, why not?

1980SANGERV-DRIVE

10-13-2003, 04:47 PM

Last time I checked I have not seen a Honda
v-drive :confused: :confused: :confused: and my boat :rolleyes: :rolleyes: does not have a airbox jawdrop jawdrop

1980SANGERV-DRIVE

10-13-2003, 04:50 PM

Or is that where the chrome reverse muffler bearings are?????????? :confused: :confused:

rrrr

10-13-2003, 07:01 PM

Too technical for you? :rolleyes: yuk

LVjetboy

10-13-2003, 10:47 PM

"The engine's only an air pump." How many times that phrase quoted on the net? So that explains everything? Ya right. So don't bother putting a blower on 'cause, the engine's only an air pump after all and it'll only draw the air it wants...the rest going to waste.
I'm talking ideas here, not brand-y scoop or brand-x.
So what if you have a properly designed and sealed scoop, made to reduce turbulence, and carbs adjusted to handle the extra air? Sorta like the blower idea. Or porting heads. Or taking the mufflers out. So an engine won't benefit from an increase in airflow? You can't put 100 mph cheek flapping airspeed to work? Hmmm....
If at launch, the scoop reads -10 psi and at 100 mph the scoop reads 0 psi...whouldn't that be a 10 psi boost? Ya I think so. Especially if you put the scoop facing aft and read -10 psi or -12 psi at 100 mph.
My point is, 0.65 psi at 200 mph doesn't tell much about the boost gained unless you know the readings at other speeds, or with the scoop backwards at 200 mph. And it doesn't tell if that scoop was designed to take advantage of ram effect. How much time at speed also makes a difference in application for obvious reasons.
Just because the scoop you're using isn't designed to flow to the carbs without turbulence, or the carbs aren't able to meter properly with that extra pressure doesn't mean the concept is bad.
Also, just because I'm posting this doesn't mean I'm saying running stock scoops forward is a good idea. Just tossing around ideas here.
jer

Rexone

10-13-2003, 11:17 PM

Jer I have no idea what you do for a living but if you do anything other than work for NASA I think you missed your calling. And I mean this in a good sorta way. :D
I just knew when he showed up we were gonna end up needin calculators to determine scoop direction on this one. :D
[ October 14, 2003, 12:17 AM: Message edited by: Rexone ]

LVjetboy

10-14-2003, 02:06 AM

To me...watching the moon reflect on lake water with stars everywhere is NASA enough. In a v-drive or a jet no difference. We all have the same passions...
http://users.lvcm.com/lvjetboy/TwoHoneys.jpg
jer
[ October 14, 2003, 03:11 AM: Message edited by: LVjetboy ]

Rexone

10-14-2003, 02:14 AM

LVjetboy:
To me...watching the moon reflect on lake water with stars everywhere is NASA enough. In a v-drive or a jet no difference. We all have the same passions... jer jer you really should be careful writing this kind of stuff. You do have an image to maintain you know. :D

1st Timer

10-14-2003, 05:49 AM

LVjetboy:
To me...watching the moon reflect on lake water with stars everywhere is NASA enough. In a v-drive or a jet no difference. We all have the same passions...
http://users.lvcm.com/lvjetboy/TwoHoneys.jpg
jer Velocity stacks with air cleaners on top = Gay.
Please keep your opinion on this topic to yourself.

1st Timer

10-14-2003, 05:56 AM

LVjetboy:
To me...watching the moon reflect on lake water with stars everywhere is NASA enough. In a v-drive or a jet no difference. We all have the same passions...
http://users.lvcm.com/lvjetboy/TwoHoneys.jpg
jer Now theres a direct link between LVjetboy and Mr.bbts if there ever was one. and it sounds gay as hell to.

rrrr

10-14-2003, 06:02 AM

LVjetboy:
"
So what if you have a properly designed and sealed scoop, made to reduce turbulence, and carbs adjusted to handle the extra air?
My point is, 0.65 psi at 200 mph doesn't tell much about the boost gained unless you know the readings at other speeds, or with the scoop backwards at 200 mph. And it doesn't tell if that scoop was designed to take advantage of ram effect. How much time at speed also makes a difference in application for obvious reasons.
Just because the scoop you're using isn't designed to flow to the carbs without turbulence, or the carbs aren't able to meter properly with that extra pressure doesn't mean the concept is bad.
jer Here's a photo for you. The designers of these cars spend hours doing computational fluid dynamics and using wind tunnel time to maximize the design efficiency of the air inlet and plenum. Even so, the advantage at 10,300 RPM and 200 MPH is barely over 1/2 PSI.
I don't know why you think "0.65 psi at 200 mph doesn't tell much about the boost gained unless you know the readings at other speeds" because going slower would only make it less. In an engine on a boat turning 6,000 RPM I would think the number would be insignificant.
You say "carbs aren't able to meter properly with that extra pressure". In a sealed plenum, the fuel metering device is not affected by "pressure". Any boost device merely increases flow through the engine, and the carbs are sized to handle increased flow, not increased pressure.
You're correct, it "doesn't mean the concept is bad", but there isn't much there. I can assure you that IRL chassis and engine manufacturers have maximized the advantages to be gained from airbox configuration and construction, but the benefits gained are not all that much.
http://www.***boat.com/image_center/data/500/109airbox-med.jpg

cyclone

10-14-2003, 09:12 AM

Jetboatguru:
Add Burrows to that list. He runs very stout but again another High dollar Olds. i though burrows ran a Pontiac??

Rexone

10-14-2003, 06:15 PM

1st timer I'll put up with a certain amount of your "gay" crap in bench racers but it ain't gonna fly here in vdrives (tech forum). If you wanna be a jerry springer participant keep it in BR.

1980SANGERV-DRIVE

10-14-2003, 06:17 PM

Im very partial to volicity stacks!!!!!!!!!
http://users.lvcm.com/lvjetboy/TwoHoneys.jpg

LVjetboy

10-18-2003, 12:36 AM

rrrr,
Even so, the advantage at 10,300 RPM and 200 MPH is barely over 1/2 PSI. I don't know why you think "0.65 psi at 200 mph doesn't tell much about the boost gained unless you know the readings at other speeds" because going slower would only make it less. Sure going slower makes it less, but how much? Doesn't 0.65 psi equate to a 5 psi boost over -5.65 psi? Or if you want to talk psia, doesn't 15.35 psia equate to a 5 psi boost over 10.35 psia? Not 1/2 a psi boost? And compared to a box facing aft? We're talking relative pressures here not pressure compared to atmospheric of 14.7. I'm guessing a box facing aft, or one not moving may have a significant negative pressure...right?
In an engine on a boat turning 6,000 RPM I would think the number would be insignificant.
Could be. I wasn't relating to rpms, but I suppose a combination of both rpm AND displacement would drive intake box pressure. Typical boat engine at 6k with more displacement than the engine turning 10k.
You say "carbs aren't able to meter properly with that extra pressure". In a sealed plenum, the fuel metering device is not affected by "pressure". Any boost device merely increases flow through the engine, and the carbs are sized to handle increased flow, not increased pressure.
Don't carbs in a blow-through design have mods to meter properly? I could be wrong...just commenting on judging the forward or aft scoop question based soley on faulty scoop designs, non-sealed features that promote turbulence...and poorly matched carbs not able to take advantage of boost.
jer