Edelbrock RPM or Holley Street Dominator?

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DrCharles

DrCharles

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Trying to choose between these two manifolds. Currently have the RPM.
Almost all street driving, until I get a 2-axle trailer because the nearest strip is 90 miles away anyhow :rolleyes:
Combo: 451, .652 gross lift ([email protected]) cam, QFT 950. For now, running bowl-blended iron heads. Will shortly be putting on PRH-massaged Speedmaster aluminum heads good for 293.5 cfm, 10.6:1.
A833, 3.91 rear (3000 rpm @ 60 mph), caltracs, dual 3" exhaust with x-pipe. And a 100-150 hp nitrous plate if I feel the need. :D

The RPM intake is known to be good for midrange torque but I wonder how much the Street Dominator gives up in the 2500-4000 rpm range compared to what it adds on top.
Thoughts?

Edited to add: I would also consider a Victor 383 but again, worried about compromising the already mediocre low-end further.
Crossposted to Moparts.
 
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Almost everybody loves the rpm, and it is a helluva good manifold.... but most dont have near as much engine as you have.
With the big head upgrade, the rear gear you have, and the possible nitrous plate use, i would go with the sd.
Engine masters did a test to counter the perception that a single plane manifold was better for plate use, and reached the conclusion that a two plane was fine, but....i still think cyl to cyl distribution is better with a single plane.
I do think the difference between the two wont be huge. My worthless opinion only.
 
@PRH , what's your opinion here? Do you think there may be some gains found by porting the RPM?
 
Exactly! I wonder if it’s viable information or just so much magazine/internet snake oil. I’d run the rpm and tune with spacers when you get to the track. If it runs best with an inch a 1-1/4 or more of carb spacers, it probably would benefit from a single plane. If it acts like it would perform best with a single plane, I would think the street dominator would be the best manifold available for the rest of the combination.
 
I currently have 1" of spacers anyway (1/2" nitrous plate, 1/2" wood open spacer mostly for heat isolation). It runs well on the butt-dyno :p
Thanks for tagging Dwayne, will see what he thinks too :)
 
How much difference between the two intakes do you think there will be? CERTAINLY not enough to justify running out and finding a Street Dominator. I bet there's not 10 HP difference.
 
RustyRatRod said:
How much difference between the two intakes do you think there will be? CERTAINLY not enough to justify running out and finding a Street Dominator. I bet there's not 10 HP difference.
Click to expand...

Check the article I linked. There was a 26 hp difference (610 vs. 636) on their iron-headed 440. Not huge, but not trivial either.
 
I say the SD and yes, I looked over the article. If the intake is sized correctly and the carb is sized correctly the single plane will kill the dual plane every single time.

The two things that kill the single plane is too big a cam and carb. On a DP manifold each cylinder breathes through just 2 venturi. So the engine thinks the carb is half its size. Now you bolt a SP on it and you’ve effectively doubled the carb size.

That, and the SP always needs less at .050 timing than a DP.

So between a carb too big and too much cam timing you see the DP win. Done correctly the SP beats it every time.

And when you get tired of that, bolt on a TR and pick up more power everywhere.
 
Well... I do have a lot of cam, but not too much carb. Driveability down to 2000-2500 is also important to me, and all the single planes I see don't make up for what they lose down low until 4500 or even higher...

If there were a tunnel ram that would fit under my six-pack hood I'd consider it! But the Edelbrock STR series don't seem to be the answer.
How about the Trick Flow intake?
 
Street or strip dominator ? Street Dominator will be fine down low, I think they both would be fine down low if you got the combination right.
 
Easy to change on a big block, go to the track run one, change it, tune it and compare.
 
DrCharles said:
Check the article I linked. There was a 26 hp difference (610 vs. 636) on their iron-headed 440. Not huge, but not trivial either.
Click to expand...

I did. Is your build exactly the same? I be damned If I'd go huntin another intake when I had a goodun already. GO for it.
 
MOPAROFFICIAL said:
Street or strip dominator ? Street Dominator will be fine down low, I think they both would be fine down low if you got the combination right.
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Yup which is why I say run what he has and tune accordingly. Oh well.
 
yellow rose said:
I say the SD and yes, I looked over the article. If the intake is sized correctly and the carb is sized correctly the single plane will kill the dual plane every single time.

The two things that kill the single plane is too big a cam and carb. On a DP manifold each cylinder breathes through just 2 venturi. So the engine thinks the carb is half its size. Now you bolt a SP on it and you’ve effectively doubled the carb size.

That, and the SP always needs less at .050 timing than a DP.

So between a carb too big and too much cam timing you see the DP win. Done correctly the SP beats it every time.

And when you get tired of that, bolt on a TR and pick up more power everywhere.
Click to expand...

Agree w/ the above^^^^^^^^^^, but u said , "mediocer" low end w/ a stroker ?!!------------ Should have an abundance of it !
 
I believe it would be safe to say that cam would be more appropriate for the 3.9-4.15 inch stroke range. Yeah, I’d just run the RPM...
 
Garrett Ellison said:
I believe it would be safe to say that cam would be more appropriate for the 3.9-4.15 inch stroke range. Yeah, I’d just run the RPM...
Click to expand...
This cam (the old "Mini-Express", slightly reground to restore taper) will make power to well over 7000 in a 440 (and even higher in a 383), but I don't have the valvetrain or oiling system to do that. I don't think I would want to turn a 4.15" stroker to 7000 either! :eek:
So for now I will be staying with the RPM. As I mentioned, the track is 90+ miles away, and no chassis dynos anywhere near here either, of course. I'm keeping an eye out for a reasonably priced SD in the meantime. As noted, they are easy to swap.
 
I had an Strip-D on my 451. loved it. 3.91 gear on a 14" tire made 1st unuseable. It had enough low end to rip though 1st and 2nd in a cloud of smoke, but the performer wasn't considered as I already had the SD. I had another Strip-D on my 340, loved that combo too. Strip Dominator in 383 was very common back then, IIRC a mag said it was the best all around intake for the 383 but I think that was before the Performer RPM came around.
<<<Oops, mine was the Street Dominator, they dont have a B strip Dominator>>>
 
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