Single plane vs. dual plane intake

Is there very much difference in engine performace with a single plane intake vs. dual plane if you are running fuel injection, even a TBI unit? I'm trying to think of a difference with a single plane, and the only thing I can think of is the vacuum signal if you were running a carb., but if you were using a fuel injection system of some kind this would eliminate this problem? But I don't always think of everything and just wanted to get some other opinions.

I'm no authority but yes you wouldn't need a strong vacuum signal with TBI or port inj. Read an article a while back where someone port injected a tunnel ram with good idle and response. They got more money to play with than I do.

Only differences that I can recall is performance wise and its probably miniscule on a FI system so I say go with whichever one you prefer

Oh, yeah. Forgot to mention RPM range. 5-6k max for dual plane reguardless.

Thanks for the input. Anyone else?

We had a very good discussion on this in this thread;

https://board.moparts.org/ubbthreads/show...rue#Post5029247

From the thread, you will see that I am a dual plane advacate, but the benefits of the dual plane would be less with TBI than with MPI, as you would only have charge volume, not mixture issues to deal with because of mismatched flow.

The intake config wouldn't matter as much with port injection but with TBI it will have the same affects as a carburetor. Keep in mind that even with old style mechanical injection systems, the velocity stack length - essentially a runner - had an affect.

Stanton;

Actually, you wind up with more problems with MPI than with TBI because the fuel is put in exactly same on each cylinder (assuming untrimmed). Any difference in airflow not only affects your charge volume, but mixture also, as the fuel is fixed. With TBI the mixture is set before the runners, so it is consistent, leaving you only with charge volume issues.

With a carb, you get both issues, as you get some mixture issues back because of carb signal issues with a single plane.

Quote:

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With TBI the mixture is set before the runners, so it is consistent, leaving you only with charge volume issues.

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That's assuming your intake provides good fuel distribution as well.

If I was to run a TBI, I would definitely go with a dual plane. Carbs perform better on dual planes and dual planes tend to be designed for better fuel distribution and better every day type driving. TBI won't need the strong vacuum signal that a carb likes, but it also depends on your efi controller. If you go port injection, then I think you could go either way. Like booster said, port injection delivers the same amount of fuel to each cylinder, so you really need to get an intake that delivers the same amount of air flow to each cylinder as well to keep your a/f ratios consistant between cylinders, be it single plane or dual plane.

On the mopar 4cyl cars I've toyed with, on the port injected cars I've found even air flow balance to make much more difference than single plane/dual plane type, where single plane type intakes that look like they should have performed awful actually ended up providing the best throttle response and performance.