Dual Plane vs. Modified Dual Plane

Ok guys, I have a question about intake manifolds. Does modifying a dual plane manifold to remove part of the divider (I'm not sure that's the technical term :o here) really gain me that much horsepower? For example in the pic below, you can see that Edelbrock removed part of the divider in there RPM Airgap Manifold, and I am just wondering what I could expect based on this. I have seen other people modify dual plane manifolds before to do something similar to this (not the air gap part, the partial divider line) but I have never made the mod myself. I am curious if any of you have and what you found the results to be. I know that it is a tradeoff between torque and horsepower, I guess my question is: is it really worth it? How much torque would I lose (ballpark) and how much horsepower would I gain (again ballpark) Also, maybe I'm a lost cause here; but, what would be the difference between that and running an open spacer between the carb and a dual plane manifold?

Thanks,
Firechicken

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Originally posted by Firechicken
Ok guys, I have a question about intake manifolds. Does modifying a dual plane manifold to remove part of the divider (I'm not sure that's the technical term :o here) really gain me that much horsepower? For example in the pic below, you can see that Edelbrock removed part of the divider in there RPM Airgap Manifold, and I am just wondering what I could expect based on this. I have seen other people modify dual plane manifolds before to do something similar to this (not the air gap part, the partial divider line) but I have never made the mod myself. I am curious if any of you have and what you found the results to be. I know that it is a tradeoff between torque and horsepower, I guess my question is: is it really worth it? How much torque would I lose (ballpark) and how much horsepower would I gain (again ballpark) Also, maybe I'm a lost cause here; but, what would be the difference between that and running an open spacer between the carb and a dual plane manifold?

Thanks,
Firechicken

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Helps when you attach the image the first time :LOL:

its a trial & error thing, some engines seem to like it, some dont seem to make much differance, some dont like it at all

from my experience themodification onlyis effective at high revs, allright for the drags, but for low to mid range you will lose some torque. Its just aquestion of tradoffs