KIKIRIKI

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

fishslayer143

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

carriljc

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.

7t2vette

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

TheSkunkWorks

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.

Metalhead140

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.

Gale Banks 80'

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.

David Mc

Why would that be? Given the vaporization of the same amount of fuel?

Since port fuel manifolds are "dry" it opens up a lot of design possibilities but the fact remains short runner and open plenums will flow well at high rpms and long runner/dual plenum will trade off that high rpm performance for low rpm torque.

<- Not convinced the dual plane manifold in the video above caused a "miss"

c3_dk

All multi point fuel injection set I've see are with single plane intake.
I've never seen a duel plane, or the possibility to select a duel plane in a multi point set.

pauldana

This^^^^^ is the correct answer.

KIKIRIKI

Thanks for all the info guys. Seems the general rules of thumb go out the window with EFI... single plane it is. Now to find something that'll fit my needs and hood clearance...

pauldana

AFR Titan is what I run

c3_dk

Also AFR Titan in my SBC 427

But I'm also very happy with my G-Team 7530 in my SBC 350 (std hood)
And still I have 12mm spacer, and 5mm hood clearance, with EZ-EFI 1.0, and 14" air cleaner.

Black04Vert

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.

carriljc

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.....

diehrd

TB can use both , Multi Port Single plane only

David Mc

You forgot 8 plane

lionelhutz

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.

LT1M21Vette