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Holley Sniper question #3070170
08/21/22 02:11 PM
08/21/22 02:11 PM
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Rittman Ohio
fourgearsavoy Offline OP
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fourgearsavoy  Offline OP
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I will be installing a Holley Sniper EFI on a buddies car and he has a dual plane intake. Will I need to remove or trim the plenum divider down? I have the manifold off right now while I'm building the engine so now is the time if need to modify the intake.
Thanks

Gus beer


64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60
Re: Holley Sniper question [Re: fourgearsavoy] #3070185
08/21/22 03:00 PM
08/21/22 03:00 PM
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Bend,OR USA
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I've been told by several very good EFI reps to never use a dual plane intake under any throttle body EFI systems shruggy work
All the direct port EFI systems I have seen are single plane designs also: work:


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Holley Sniper question [Re: fourgearsavoy] #3070235
08/21/22 06:28 PM
08/21/22 06:28 PM
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Oregon
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AndyF Offline
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Originally Posted by fourgearsavoy
I will be installing a Holley Sniper EFI on a buddies car and he has a dual plane intake. Will I need to remove or trim the plenum divider down? I have the manifold off right now while I'm building the engine so now is the time if need to modify the intake.
Thanks

Gus beer


You don't need to do anything to the intake to run a Sniper. The Sniper will work just like a carb with fuel being introduced into all four barrels. So if a carb works on that intake then so will a Sniper. Your buddy might notice a part throttle whistle from the Sniper. If there is room you could put a thin four hole spacer under the Sniper to eliminate the whistle.
Here is the setup I used on my Coronet for a few years. This was a low deck 512 with a Performer RPM intake. It made excellent power on the dyno and ran really hard on the street.

DSC_2521 (Large).jpeg
Last edited by AndyF; 08/21/22 06:31 PM.
Re: Holley Sniper question [Re: AndyF] #3070250
08/21/22 07:24 PM
08/21/22 07:24 PM
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Taxes & Virus's R-US, NY
Dragula Offline
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I recomend thinning down the divider on a DP as mush as possible and running an open spacer below the TB...Work really well on my FAST system.

Mine loved the change...

Last edited by Dragula; 08/21/22 07:26 PM.

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Holley Sniper question [Re: Dragula] #3070257
08/21/22 08:04 PM
08/21/22 08:04 PM
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Rittman Ohio
fourgearsavoy Offline OP
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Thanks a bunch guys up I have a few spacers on the shelf that would work.

Gus beer


64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60
Re: Holley Sniper question [Re: fourgearsavoy] #3070271
08/21/22 08:33 PM
08/21/22 08:33 PM
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AndyF Offline
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If you have room you can play with spacers. An open spacer on a dual plane intake will add some top end power, but with a Sniper you'll hear a whistle sound.

Re: Holley Sniper question [Re: AndyF] #3070323
08/21/22 10:38 PM
08/21/22 10:38 PM
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Rittman Ohio
fourgearsavoy Offline OP
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The engine is a 408 Magnum with a mild hydraulic roller going into a 73 Satellite/Roadrunner clone with the bubble hood so clearance shouldn't be a problem.

Gus beer


64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60
Re: Holley Sniper question [Re: fourgearsavoy] #3070358
08/22/22 08:08 AM
08/22/22 08:08 AM
Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
Dragula Offline
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Originally Posted by fourgearsavoy
The engine is a 408 Magnum with a mild hydraulic roller going into a 73 Satellite/Roadrunner clone with the bubble hood so clearance shouldn't be a problem.

Gus beer


Mine was a 360 with a hydraulic 484 cam, and it loved the open plenum change with the spacer...It seemed more responsive and just wanted to run....

DSC09762.JPGDSC09418.JPG

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Holley Sniper question [Re: Dragula] #3070369
08/22/22 09:09 AM
08/22/22 09:09 AM
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Posts: 8,005
Tulsa OK
Bad340fish Offline
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I know engine masters did an episode carb vs EFI and the EFI hated the dual plane intake. All engines are different though.

Episode
https://www.dailymotion.com/video/x3moa13


68 Barracuda Formula S 340
87 "Chrysler" Conquest
Re: Holley Sniper question [Re: Bad340fish] #3070393
08/22/22 10:18 AM
08/22/22 10:18 AM
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Oregon
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Here is a Holley Sniper on a Performer RPM dual plane intake. It pulls hard all the way to 160 mph wheel speed. I can guarantee that there is zero problems with a Sniper on a good dual plane intake manifold. We've tested dozens of them over the years, they work just fine.
https://youtu.be/xG3-_YJGdZ8

Re: Holley Sniper question [Re: fourgearsavoy] #3070969
08/24/22 05:13 AM
08/24/22 05:13 AM
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Aurora, Colorado
451Mopar Offline
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If you have the hood clearance, I would use a open phenolic carb spacer.
I think the open spacer would allow the MAP sensor to sense average pressure of both planes?
The phenolic will get the EFI unit further from the intake manifold heat. The Sniper / Fitech units have the electronics inside the throttle bodies, and electronics don't like high temperatures.







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