Performer RPM Intake: Improvement possible?

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360duster

360duster

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Hi Guys,
i´m running successfully an EDE Performer RPM Intake on my 408 SB. At the moment i´m switching to some cnc ported heads and a bigger cam (hydr. Roller, 248°@.050" / .620" Lift, 113° LSA) and since the intake is removed from the engine i thought about improvements. I use a 1" tapered spacer and like to keep it, it improved idle noticeably with the old cam. The divider in the intake looks like it´s not helping airflow - what do you think, is there anything to make it better? Of course, i could buy a single plane....but for now i´d like to keep the dual plane. Thanks for your help!

Michael

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What size carb? What about exhaust. I can see other performance bottle necks before intake. What is compression ratio? Torgue converter and rear gear really need to match this combo to get the most out of it. If it where mine: I'd want 3.91 or bigger rear gear and 3500+ stall.
 
Hi, forgot about the rest of the combo: 750 Ultra DP, 3500 rpm 9.5" converter, 904 trans, 4.11 Gears with 27" Tires. Compression is 10:1.

I run cheap 1 5/8" headers, but can´t afford to get bigger ones now. Rest of exhaust is 3" system with X-Pipe and cutouts, then going into some dynomax turbos. I run open exhaust at the track. PB with iron heads (indy X) and the old cam (242/236 @ .050", around .580" Lift) was 11.40, i´d really like to get into the ten second zone what i think it will...but if there is any improvement possible at the intake i´d like to do it.

Michael
 
I would agree the spacer appears to be effecting the design of the dual plane manifold. With so much modification to the existing combination, I would not worry about it until the final tune. You might change your mind about keeping the spacer at that point.
 
Single plane and bigger headers. Sorry, just teasing. :poke:

Joking aside, I have seen mods to dual planes by cutting down the divider wall so turning the dual plane into single plane to a certain (limited) degree.
But then I have no personal experience and I don't know how that would help in your case.
 
You're on the right track. Take out the grinder and cut out the dyed area.
 
You spacer is helping by sharing the two sides of the intake. Letting one side draw from the other when it needs it.
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This is the reason for the notch cut into a lot of intakes. Don't know if there is anything to gain by cutting out the divider if you want to keep the spacer.
 
With those upgrades I'd go with a single plane..but if you want to use the dual plane mill down the center divide and go with an open spacer.. I'm currently putting together a 340 with the cnc'd Edelbrocks and switching from an Air Gap to a Victor 340...
 
Unless you can test it a lot and have the ability to put back what you take out, I wouldn't mess with it.

Can't tell you the number of engine with a dual plane intake the loved an open spacer on top. Happens all the time!

Sell the RPM, get a bigger single plane and more converter with your new camshaft.
 
I would definitely grind away the areas that you have marked, since that area is creating a shelf below your spacer. As far as lowering the divider, I would keep the height and just thin it a little and radius the top. Remember it's easier to remove material than it is to add it. Here's what I did to my ld4b with plans to try a spacer:

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the rpm is a great manifold but in my opinion you are outgrowing it. why go and put all that time into it when a good single plane will fit the bill .unless your in love with it lol oh ya and bigger headers.lol
 
Go a step bigger on the cam and move away from the Hyd. lifter to a solid roller lifter. Single plane intake!
 
IMO install a single plane, these 4" crank think they're big blocks. A Weiand X-CELerator or a Victor 340 would work great on your engine.
 
360duster said:
Hi, forgot about the rest of the combo: 750 Ultra DP, 3500 rpm 9.5" converter, 904 trans, 4.11 Gears with 27" Tires. Compression is 10:1.

I run cheap 1 5/8" headers, but can´t afford to get bigger ones now. Rest of exhaust is 3" system with X-Pipe and cutouts, then going into some dynomax turbos. I run open exhaust at the track. PB with iron heads (indy X) and the old cam (242/236 @ .050", around .580" Lift) was 11.40, i´d really like to get into the ten second zone what i think it will...but if there is any improvement possible at the intake i´d like to do it.

Michael
Click to expand...
Is that cam a typo; 242/236
 
Ok Guys, majority seems to like a single plane much better for my combination.....í´ll consider this as a next step (all playing money spent at the moment ;-)). I always liked the Indy single plane...maybe one comes up used over the year.

What do you guys think is the better choice: Ede Victor 340 / Super Victor / Indy 360 or sth. low profile like the torker / x-celerator? I have no experience.

AJ/FormS: i mixed it up, intake is 236 / exhaust 242°, it´s a comp XR286HR Cam that i used before.

Thanks at all for the feedback!

Michael
 
Michael, on single plane intakes, considering your build/cam specs, I like a MoPar M1.
 
ok guys, here is the result.

I do not know if it´s worth anything. I do know that i like it better than before ;-).

Of course i opened up the runners to gasket size about 1" into the runner.....i feel better now. And i´ll watch out for single plane intakes for next step ;-))

Have a nice day!

Michael

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Good to go! Now what are going to put on top of it??
 
Stroked, give us your real world results!
I know you did this mod.
 
Naaaa, if I'm going to space it up, I'd start with a 1/2 and work upwards.
 
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