Single plane or dual plane with EFI?

[furious70]

On my son-in-laws 318 we installed a throttle body efi on a performer manifold. we couldn't get it tuned real well at cruise rpm. connected laptop and watched the MAP sensor at it would bounce/vary alot up to peak torque. added a spacer - got better, added another spacer -1 1/2" total, a little better. swapped out to a single plane and we got it tuned easy.

I think the dual plane manifold and the small plenum amplify the pulses and single plane dampens the pulses for better MAP reading on his engine. I also think it would vary from combo to combo.

that's interesting. I only have my experience and 2 other friends with home built multiport - all 3 ran dual planes (one tried 3 different intakes, dual and single plane) never saw the MAP act up - you should have seen a vacuum gauge do the exact same thing then, right? Where were you drawing the feed from?

 

[6872n73]

Before tbefi we installed the performer intake and a 600 carb put a vacuum gauge on and tuned it for idle I don't recall any readings at midrang but it ran good with the carb

 

[origcharger]

I have an Edelbrock performer with no spacer or mods on my Holley Sniper equipped 440, seems to be fine

 

[66chargerpat]

I think with 500+ ci and a four speed you would be better off with the single plane. But it cant hurt to try it first with out the spacer. I think some of the poster think you haven't bought the tbi yet. Which tbi did you go with?

 

[furious70]

yes, my advice was pick the intake you'd use with a carb. 500" stroker might very well have a single plane if not the rpm perf.

 

[Bad B-rad]

Do the Holley and FI tech use similar sensors to tune?
I have seen an episode of engine masters where a duel plane intake gave them issues and they couldn't tune it, so they switched to single plane, and then it worked fine.

I have also noticed that it seams to be more the Holley throttle body injection units that are sensitive to the duel/single plane intake, so I wonder if the sensors are different between the FI TECH vs SINPER?

 

[rumblefish360]

that's interesting. I only have my experience and 2 other friends with home built multiport - all 3 ran dual planes (one tried 3 different intakes, dual and single plane) never saw the MAP act up - you should have seen a vacuum gauge do the exact same thing then, right? Where were you drawing the feed from?

That’s the thing right there! “Multi Port” is different than a throttle body injection and where the PIA can come in.

 

[6872n73]

that's interesting. I only have my experience and 2 other friends with home built multiport - all 3 ran dual planes (one tried 3 different intakes, dual and single plane) never saw the MAP act up - you should have seen a vacuum gauge do the exact same thing then, right? Where were you drawing the feed from?

The map sensor was connected to a port in the center of the rear of the carb I missed this before

 

[andyf]

Is it really worth the cost and effort to swap out an Edelbrock RPM intake for a single plane intake like a Street Dominator with throttle body EFI? I currently have a 1" spacer under the TB on the Eddey RPM intake and it works very well. Hood wont close now. Running without the hood is super cool BTW

Try it and see what you think. Intake manifolds don't cost very much money and they only take a few minutes to swap on a big block. I've used both dual plane and single plane with Holley Sniper throttle body EFI and they both work okay. On a 500 inch engine I'd recommend a single plane intake since the Performer RPM isn't really designed to feed 500 inches at WOT. The RPM intake will work just fine on the street but the distribution can be an issue at WOT.

 

[andyf]

The engine is a 440 based 505 cu". 4 speed manual trans. I could try removing the 1" spacer and see what the result is.

Here is my Coronet on the chassis dyno with a Holley Sniper, Performer RPM intake, and a 5 speed manual. It worked okay. I eventually swapped over to a Trick Flow single plane intake which worked even better, but the RPM worked okay.

 

[Paul_G]

I think some of the poster think you haven't bought the tbi yet. Which tbi did you go with?

I picked up a used Edelbrock E street system. It had a bad MAP sensor, replaced it and it works great.

Do the Holley and FI tech use similar sensors to tune?
I have seen an episode of engine masters where a duel plane intake gave them issues and they couldn't tune it, so they switched to single plane, and then it worked fine.

That is what makes ask the single plane/duel plane question. And why I put a 1" open spacer on top of the duel plane intake. I bought the RPM duel plane with the intent of using a Holley 850 CFM carb. Then the E Street system became available and used that.

 

[andyf]

Do the Holley and FI tech use similar sensors to tune?
I have seen an episode of engine masters where a duel plane intake gave them issues and they couldn't tune it, so they switched to single plane, and then it worked fine.

I have also noticed that it seams to be more the Holley throttle body injection units that are sensitive to the duel/single plane intake, so I wonder if the sensors are different between the FI TECH vs SINPER?

If the Enginemasters guys had trouble with a dual plane install then they should've spent some time and figured it out rather than giving the people the impression that dual planes don't work with EFI. A Holley Sniper works just fine on a dual plane intake. Depending on the intake you might want to notch the divider or cut it down a bit but that is normal hot rod tuning.

 

[biomedtechguy]

I'm going to resurrect this thread because I missed it, and the intake I lost sleep over from time to time until I finally found a really nice one at a decent price, and made it mine! Now I'm working on a lot of other stuff that's been added to my Roadrunner, but the "single plane vs dual plane for EFI" question is a good fit for this intake vs my stock 6bbl.
I've invested in a lot of Promax parts and labor on my Holley 2bbl carbs, so I'm definitely going to try them first, along with the mods "6bbl FLASH" used.
It's the Weiand P3690982 6bbl single plane old school Super Stock intake.
Unless my 541 stroker is finished by the time I get to the intake, I'm going to play around with it on my current 440.
My main point is the F&B 6bbl EFI direct port injection system turns the Weiand into a dry manifold, and that eliminates the main problems that it has: fuel pudding and uneven distribution.
I'd love to use the FiTech 3x2 but it has a hard ceiling of 600 HP and my 541 is slated for more than that.
Here's the F&B system on the Weiand intake: