Author Topic: Velocity Stacks  (Read 5554 times)

Offline cudabob496

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Velocity Stacks
« on: June 02, 2015 - 11:48:57 PM »
Do velocity stacks work? Seems like the air would just pass over the top
of the stack for the most part?
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000




Offline Chryco Psycho

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Re: Velocity Stacks
« Reply #1 on: June 03, 2015 - 12:07:49 AM »
Yes they work , the Ramchargers probably developed the fist ones on the High & Mighty back in 58 , they straighten the airflow into the carb

Challenger - You`ll wish You Hadn`t

Offline cudabob496

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Re: Velocity Stacks
« Reply #2 on: June 03, 2015 - 12:23:28 AM »
Yes they work , the Ramchargers probably developed the fist ones on the High & Mighty back in 58 , they straighten the airflow into the carb

OK, good to know, but it seems like the air would pass over the top, and create a negative
pressure above the stack.  Seems like there is no ram air kinda effect.
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline RzeroB

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Re: Velocity Stacks
« Reply #3 on: June 03, 2015 - 04:49:20 PM »
CudaBob, Your avatar pic - that's a pic of your current engine isn't it? I think you have one of the best air induction and filtering setups going right there. The sealed air cleaner with the dual snorkels and fresh air inlet hoses leading forward to draw cooler ram air would be hard to beat. Ford had it on their Thunderbolt and Olds put it on their W-30 package from the factory.
Cheers!
Tom
St Louis, MO

Former owner of 16 classic Mopars. "It is better to have owned (Mopars) and lost then to have never owned at all" (apologies to Alfred Lord Tennyson)

Offline cudabob496

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Re: Velocity Stacks
« Reply #4 on: June 03, 2015 - 08:23:38 PM »
I agree, the setup I have is working great. I took the car out yesterday, and it is running perfect, with AFR at 13.5 when cruising.
But I've had the car 25 years, and was kinda looking for a project.  Plus, if set up right, a tunnel ram with my heads and cam should
make a fair amount more power. And I kinda want the car to make an even bigger visual statement. A tunnel ram is fairly wild.
So, will keep chewing on the idea. And, I can always return the car to its present condition, if I want.

Only negative about the tunnel ram, is that there will be no looking innocent or incognito.  Everyone will know its
purpose is racing!

Hey, with a tunnel ram, those carburetors and inlet air are gonna be nice and cold or cool, temp wise!
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline cudabob496

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Re: Velocity Stacks
« Reply #5 on: June 04, 2015 - 01:45:36 AM »
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline HP2

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Re: Velocity Stacks
« Reply #6 on: June 04, 2015 - 09:18:21 AM »
The downstroke of the piston create a negative pressure at the bottom of the stack which still pulls air despite the speed of the air passing over the stacks and it fills the tube because of the positive atmospheric pressure that is trying to equalize the differential. Additionally, the ability to tune the length to best match a specific rpm range power target makes them more powerful, albeit similar to the principle of how a tunnel ram works.

Stacks have been used successfully for decades at speeds higher than we can hit in our cars. Are they the ultimate, no or they would still be in use in upper tier classes, but they were and are still heads and shoulders above a standard carb. However, the advent of EFI and its ability to constantly tune and adjust means they have bypassed MFI as an injection alternative.

Offline cudabob496

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Re: Velocity Stacks
« Reply #7 on: June 04, 2015 - 01:00:31 PM »
The downstroke of the piston create a negative pressure at the bottom of the stack which still pulls air despite the speed of the air passing over the stacks and it fills the tube because of the positive atmospheric pressure that is trying to equalize the differential. Additionally, the ability to tune the length to best match a specific rpm range power target makes them more powerful, albeit similar to the principle of how a tunnel ram works.

Stacks have been used successfully for decades at speeds higher than we can hit in our cars. Are they the ultimate, no or they would still be in use in upper tier classes, but they were and are still heads and shoulders above a standard carb. However, the advent of EFI and its ability to constantly tune and adjust means they have bypassed MFI as an injection alternative.

Seems a scoop, over the stacks, to direct the air down into them, would be an improvement.
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline cudabob496

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Re: Velocity Stacks
« Reply #8 on: June 04, 2015 - 08:54:41 PM »
Problem I'm having right now is finding a decent air filter for velocity stacks, that
also looks good!

I like the look of the stacks by themselves. Maybe a little fine screen down inside them?
Like the screen on a thottle body of a FI car?
« Last Edit: June 04, 2015 - 08:59:03 PM by cudabob496 »
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline Chryco Psycho

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Re: Velocity Stacks
« Reply #9 on: June 05, 2015 - 03:24:51 PM »
A screen fine enough to be effective will also be restrictive

Challenger - You`ll wish You Hadn`t

Offline cudabob496

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Re: Velocity Stacks
« Reply #10 on: June 06, 2015 - 04:05:13 PM »
A screen fine enough to be effective will also be restrictive

Ya, and the 5 inch K&Ns that fit on each top of the velocity stacks don't look too cool.

And the Hillborn scoop? I'll have to see what size K&N will fit in there! I don't want
a 496 starving for air!
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline HP2

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Re: Velocity Stacks
« Reply #11 on: June 07, 2015 - 05:36:56 PM »
However, the total square inches of exposed filter on the dual stack K&Ns actually exceeeds the available square inches on a traditional 14" round air filter.

Offline cudabob496

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Re: Velocity Stacks
« Reply #12 on: June 07, 2015 - 09:16:00 PM »
However, the total square inches of exposed filter on the dual stack K&Ns actually exceeeds the available square inches on a traditional 14" round air filter.

Yes, probably a 3 inch high 14 inch, without the K&N lid.

Now I'm considering a Hilborn scoop on top of my K&N lid, but still
just an idea under consideration.
« Last Edit: June 09, 2015 - 03:56:52 PM by cudabob496 »
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline cudabob496

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Re: Velocity Stacks
« Reply #13 on: June 08, 2015 - 10:01:07 PM »
A screen fine enough to be effective will also be restrictive

didn't the old fuelie set ups in the 60's just have screens at the bottom of the tube stacks?
72 Cuda, owned 25 years. 496, with ported Stage VI heads, .625 in solid roller, 254/258 at .050, 3500 stall, 3.91 rear. 850 Holley DP, Reverse manual valve body.

1999 Trans Am, LS1, heads, cam, headers, stall, etc! Love to surprise the rice rockets with this one. They seem so confident, then it's "what the heck just happened?"

2011 Kawasaki Z1000

Offline roadman5312

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Re: Velocity Stacks
« Reply #14 on: June 09, 2015 - 07:53:06 AM »
Looks like maybe screens on top.   :dunno:  Maybe to keep her feet from getting sucked in.   :smilielol:
« Last Edit: June 09, 2015 - 05:07:31 PM by roadman5312 »