EFI - Dual or Single Plane Intake?
Thread Starter
Instructor
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EFI - Dual or Single Plane Intake?
Will be doing an engine rebuild/upgrade in the next couple of months and trying to lay out what parts I will need and how they will work together. My end goal is 350-400 hp, very streetable and reliable engine. I want a nice idle, low end torque, and am not looking to set any records at the drag strip. Everything points at a dual plane intake... hoooooowever....
My question is what style intake do I need for an EFI (specifically, I will be buying an FiTech Go Street 400)??
The reason I ask is because I watched an episode of Engine Masters (
), and they had issues with their EFI system and the culprit was the dual plane intake (single plane resolved the issue).
A few posts (like this one) confirm this being an issue, but don't instill any confidence in the outcome of using a single plane and having a solid streetable motor.
Anyone have experience with this? Can I get away with a single plane and have the thing idle at 500-600rpm?
Thanks as always
My question is what style intake do I need for an EFI (specifically, I will be buying an FiTech Go Street 400)??
The reason I ask is because I watched an episode of Engine Masters (
A few posts (like this one) confirm this being an issue, but don't instill any confidence in the outcome of using a single plane and having a solid streetable motor.
Anyone have experience with this? Can I get away with a single plane and have the thing idle at 500-600rpm?
Thanks as always
Drifting
Joined: Aug 2009
Posts: 1,346
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From: new iberia la
My guess would be that an AirGap Dual Plane with the divider cut down would be the optimum choice.. or a spacer on top of a regular dual plane ..single plane on your power level and hiway gears are overkill and produce poor idle and low speed drivability
Le Mans Master
Joined: Jan 2001
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I suggest reading some of the EFI forums
They generally recommend single plane intakes. Makes sense, but you need to read about it yourself to come to your own conclusion. I have Port EFI so it's no-nevermind to me..... I have FAST EFI so I read the cpgnation forum.
The ORIGINAL and bestest
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From: Toronto Ontario
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Here are some threads from the FAST product support forums on this subject:
http://www.cpgnation.com/forum/threa...e-plane.25871/
http://www.cpgnation.com/forum/threa...ualplane.26264
http://www.cpgnation.com/forum/threa...-intakes.26163
http://www.cpgnation.com/forum/threa...s-single.26325
Last edited by 7t2vette; May 21, 2017 at 05:58 PM.
Le Mans Master
Joined: Apr 2007
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From: Graceland in a Not Correctly Restored Stingray
Some good discussions posted by 7t2vette there. 
EFI doesn't need to "see" a vacuum signal in order to accurately meter out A/F mixture as does each carb venturi, which is why carbs tend to "like" dual plane intakes at lower and mid RPM ranges, as they divide those signal pulses by fewer venturis. However well they may function as a solution in many a carbureted application, fundamentally, the dual plane should IMHO be considered as little more than a crutch necessitated by shortcomings from which EFI doesn't suffer.
EFI doesn't need to "see" a vacuum signal in order to accurately meter out A/F mixture as does each carb venturi, which is why carbs tend to "like" dual plane intakes at lower and mid RPM ranges, as they divide those signal pulses by fewer venturis. However well they may function as a solution in many a carbureted application, fundamentally, the dual plane should IMHO be considered as little more than a crutch necessitated by shortcomings from which EFI doesn't suffer.
Drifting
Joined: Aug 2015
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From: NSW, Australia
C3 of Year Finalist (track prepared) 2019
Agree with all the above, but my Fitech (and I know a few others on here) runs great on my performer rpm dual plane (not an Air Gap so no cut down divider). Having said that, I would have bought a single plane if I were buying an intake, but I had the Performer RPM already and figured it was worth trying. My engine is ~500hp.
Safety Car
Joined: Nov 2008
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From: Seattle Washington
Sounds like the EFI system You are planning on using is a Carb replacement. It will make more HP than a Port Injection system because the Fuel is introduced sooner and has more of a cooling effect. It will also have better Throttle response. A Sequential Port Injection system will idle better, have better Emissions and get better fuel millage. They way I understand it at Idle and low RPM the Cam will allow a certain amount of the Fuel-Air to be pushed back up the port and then it will go back down another port near by. This causes the rough idle that a Big Cam motor has. Since a Port injection design has less chance of the Fuel going down the wrong port there is less need for a Duel Plane. This is why most if not all Port EFI manifolds are single plane.
Racer
Joined: Mar 2003
Posts: 448
Likes: 21
From: Klein Texas
It will make more HP than a Port Injection system because the Fuel is introduced sooner and has more of a cooling effect.
Since a Port injection design has less chance of the Fuel going down the wrong port there is less need for a Duel Plane. This is why most if not all Port EFI manifolds are single plane.
<- Not convinced the dual plane manifold in the video above caused a "miss"
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Race Director
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From: California
Some good discussions posted by 7t2vette there.
EFI doesn't need to "see" a vacuum signal in order to accurately meter out A/F mixture as does each carb venturi, which is why carbs tend to "like" dual plane intakes at lower and mid RPM ranges, as they divide those signal pulses by fewer venturis. However well they may function as a solution in many a carbureted application, fundamentally, the dual plane should IMHO be considered as little more than a crutch necessitated by shortcomings from which EFI doesn't suffer.
EFI doesn't need to "see" a vacuum signal in order to accurately meter out A/F mixture as does each carb venturi, which is why carbs tend to "like" dual plane intakes at lower and mid RPM ranges, as they divide those signal pulses by fewer venturis. However well they may function as a solution in many a carbureted application, fundamentally, the dual plane should IMHO be considered as little more than a crutch necessitated by shortcomings from which EFI doesn't suffer.
Race Director
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From: California
Safety Car
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Burning Brakes
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From: Dallas TX
Correct me if I am wrong but I believe all the multipoint EFI have their own intake manifold with the injectors at each intake. They can't be used with an existing manifold at all. The carb replacement style TBI EFI however, do prefer single plane intakes from what I researched.
Le Mans Master
Joined: Jan 2001
Posts: 6,743
Likes: 1,385
well now.....
I have a multipoint RamJet 350 being controlled by EZ-EFI 2.0; I wouldn't really consider it a "single plane" in the generic use of that term, but I guess in some sort of sense it kind of is.....
Race Director
Joined: Apr 2007
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From: South Western Ontario
GM TBI systems used dual plane manifolds, so in theory a dual plane can work with TBI injection. Of course, the intake was designed with TBI in mind.
At one time, I ran a 350 with a Performer intake, adapter and GM TBI and the plugs all looked decently matched and it ran well.
But, if FiTech or Holley or FAST says to run their system on a single plane then I'd probably do what they recommend unless I already had an intake.
At one time, I ran a 350 with a Performer intake, adapter and GM TBI and the plugs all looked decently matched and it ran well.
But, if FiTech or Holley or FAST says to run their system on a single plane then I'd probably do what they recommend unless I already had an intake.
