Single or dual plane intake with EFI
Thread Starter
Safety Car
Joined: Jan 2008
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From: Aarhus, Denmark
But as I understand it, a dual plane is good from lets say 1500 to 5500/6500, and a single is from 3000 to 8000rpm.
So as I see it, a dual intake is more correct for street?
So as I see it, a dual intake is more correct for street?
Le Mans Master
Joined: Mar 2001
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From: Lincoln, CA
We did a Holley setup and the rear hole was blocked by the Dual plane wall. He didn't want to change intakes so we added a open spacer so the terminator could read the air flow.
See the big triangle in the back. It ran real bad in the beginning.
See the big triangle in the back. It ran real bad in the beginning.
Last edited by ddawson; Oct 4, 2016 at 02:38 PM.
Thread Starter
Safety Car
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From: Aarhus, Denmark
I don't know how a EZ-EFI 1.0 looks under the throttle body.
But my car/engine run fine.
Race Director
Joined: Sep 1999
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From: Plano TX
The 3,000 rpm & up is for a carb. With EFI that same intake would be idle-8000 rpm. Note that runner length & diameter still matters with EFI, but single/dual plane doesn't. Dual plane will just make less power due to less flow with no advantage at low rpm.
Thread Starter
Safety Car
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From: Aarhus, Denmark
This is what I was looking for THANKS !!
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Le Mans Master
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From: Las Vegas - Just stop perpetuating myths please.
You're EFI system is still a wet flow system same as the carburetor it replaces - though mixture is electronically controlled. So the same reasons for using a single plane or a dual plane should still apply. Cam and RPM range usually determine this but power levels may also.
Good to read you are mastering the EFI system c3_dk. I expect soon you will be schooling us with how to operate it.
Good to read you are mastering the EFI system c3_dk. I expect soon you will be schooling us with how to operate it.
Had a 1976 L-82, 4-sp
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From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
A properly set up carb can come close to equal an efi setup. So manifold choice is still the same whether it be dp or sp, imo. The fuel just needs to be atomized properly as it enters the combustion chamber, efi with an advantage as the fuel enters the intake manifold. There are sp intakes that work below 3000 rpm and are fine for street driveability such as my Team G and Holley 650 DP with 4-speed. I needed to increase the squirter to 0.040" to compensate for the open plenum to eliminate the off idle hesitation.
Thread Starter
Safety Car
Joined: Jan 2008
Posts: 3,795
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From: Aarhus, Denmark
You're EFI system is still a wet flow system same as the carburetor it replaces - though mixture is electronically controlled. So the same reasons for using a single plane or a dual plane should still apply. Cam and RPM range usually determine this but power levels may also.
Good to read you are mastering the EFI system c3_dk. I expect soon you will be schooling us with how to operate it.
Good to read you are mastering the EFI system c3_dk. I expect soon you will be schooling us with how to operate it.
BUT I learn a bit everyday :- )
I think I will install my AFR single intake this winter, the driving season is soon over, so now could be a good time to replace it.
Or can anyone recommend a good single intake for std. hood?
That will fit up a against AFR 195 heads?
Race Director
Joined: Apr 2007
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From: South Western Ontario
As already stated, the runner length and diameter to make the best power curve depends on the engine combination, not how the fuel is being introduced into the engine. Due to packaging, the only way to increase the runner length of a single plane is by making the intake taller or putting bends in the runners aka making the intake into a dual plane. So, if you want to fit under a hood then you may need a dual plane to get the runner length the engine wants.
EFI can make a short large runner single plane intake and high CFM throttle body work where a similar CFM carb would not, but this capability shouldn't be confused with the proper matching of components when building the engine. If the short large runners are wrongly matched to the carb engine then they are still wrongly matched to the EFI engine.
Also, systems like the EZ-EFI or the FiTech absolutely do depend on the vacuum signal since the two main inputs controlling the fueling are vacuum and rpm. What they don't depend on is the air flow rate through the throttle body where a carb venturi works due to the air flow rate through the venturi.
EFI can make a short large runner single plane intake and high CFM throttle body work where a similar CFM carb would not, but this capability shouldn't be confused with the proper matching of components when building the engine. If the short large runners are wrongly matched to the carb engine then they are still wrongly matched to the EFI engine.
Also, systems like the EZ-EFI or the FiTech absolutely do depend on the vacuum signal since the two main inputs controlling the fueling are vacuum and rpm. What they don't depend on is the air flow rate through the throttle body where a carb venturi works due to the air flow rate through the venturi.
Last edited by lionelhutz; Oct 5, 2016 at 10:16 AM.
Had a 1976 L-82, 4-sp
Joined: Mar 2011
Posts: 5,338
Likes: 1,213
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
I'm still trying to crawl cardo0
BUT I learn a bit everyday :- )
I think I will install my AFR single intake this winter, the driving season is soon over, so now could be a good time to replace it.
Or can anyone recommend a good single intake for std. hood?
That will fit up a against AFR 195 heads?
BUT I learn a bit everyday :- )
I think I will install my AFR single intake this winter, the driving season is soon over, so now could be a good time to replace it.
Or can anyone recommend a good single intake for std. hood?
That will fit up a against AFR 195 heads?
Thread Starter
Safety Car
Joined: Jan 2008
Posts: 3,795
Likes: 435
From: Aarhus, Denmark
Looking good resdoggie, and 4" that is great :-)
I can't find the port size for my AFR 4802 intake, and it is installed in my SBC 427, but I can see that the Team G fits perfect to AFR, but also the Edelbrock 2900 fits good.
If I took the Team G 7532, then I could CNC it down to fit my hood.
Thx,
John
Race Director
Joined: Apr 2007
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From: South Western Ontario
The 2701 is a fairly decent manifold so compared to the Team G so I doubt you're giving up more than 5-10 ft-lbs of torque through the midrange and maybe 10-20ft-lbs up top. It's possible you're making the same or even a little more torque down low.
Thread Starter
Safety Car
Joined: Jan 2008
Posts: 3,795
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From: Aarhus, Denmark
Thread Starter
Safety Car
Joined: Jan 2008
Posts: 3,795
Likes: 435
From: Aarhus, Denmark
What would be best, 4" air filter or 1" spacer?
Last edited by c3_dk; Feb 28, 2017 at 12:25 PM.
Had a 1976 L-82, 4-sp
Joined: Mar 2011
Posts: 5,338
Likes: 1,213
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
I had about 1/10" clearance but my motor doesn't move much as there is no sign of interference with the hood. I also have a Holley Street HP which may have a lower flange height than your efi set up. The exact drop down from the carb flange to the bottom of the base is exactly 1-11/16".