I have heard good things about the Edelbrock Performance RPM, but it is a dual plane manifold. I can get this manifold for 20 bucks cheaper than in Jegs right now, but i have to act quick. A 454 670cfm TBI will be going on top of it. Also, i'm planning to put this combo on a new 350 in the future. Please advice on the manifold.

p.s. For now, i will be using this manifold along with a 454 TBI on the stock 305 with full exhaust. Thanks.

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Mods:Hooker Aerochamber 3" exhaust, gutted kitty,
March 2 piece underdrive pullies, smog pump gone,
14x4 K&N, 3.42 gears,
Eibach springs with KYB's all around.
Appearance: Harwood cowl hood, Z-28 wing, painted black(7/20/00)-original color was light blue
*All these mods were made this year
Stock Options:120,000 miles on motor, 5spd, TBI, 305, T-tops
Run a best of 16.7 @85mph before gears

 

tbi works great with single plane, at least that is the concensus from people who know what they are talking about here on the tbi board. many are running the torquer2 and weiand stealth single planes.

do a search for either of these here and you will see good input. Searching is always the way to go.

 

Pablo has posted one here about his friend's convertible with the 670 TBI on top of the rpm manifold that was running super strong with the truck engine in it. (Yukon i think)

That's why i thought that the rpm manifold might be a good idea.

Also, do you think that the rpm manifold with a 600 cfm carb would be more powerful than a 670 cfm TBI w/ weiand stealth or torquer2. I wish someone had dyno numbers for these two applications. The reason i'm asking is because there is still a possibility that i might go carb, but please, no flames intended.

 

if you want 12s from a 350 TBI you need a single plane intake. shane B came close when he was running low 13s.

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-Tas
'89 Formula WS-6
[soon to be Torch Red with black hood and headlights =) ]

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

Super GRK_Taz World
EFI & Intake Options
AOL IM: superGRtaz
ICQ 82881207

 

Can you guys tell me the main difference between the single plane and the double as far as drivability and performance? thanks

 

Believe it or not, that is not as simple question as you would think. The main difference between dual and single plane manifols is the intake velcity at lower rpms. There are many others, but this is the primary difference. Travel back with me as we visit the age of the dino...I mean carbs, lol.

To really understand, take a quick look at how a carb works. The way it meters fuel is based on vacuum going through a venturi. Think of vacuum as velocity for this example. Because it relies on the intake velocity to meter fuel, you don't want a manifold that flows alot of air slowly, but you want the air to move faster to aid the carb in metering fuel. See, there is a direct relationship between pressure and flow. If you increase the amount of air that the manifold can flow, you decrease the pressure for the given amount of flow. Because of this loss of pressure, but more air, it is hard to use a single plane manifold on the streets with carbs and not loose much low end. That is why you see these manifolds advertised for race only, and 3000rpms and up. That is becasue you need to keep the rpms up to achieve a higher velocity intake charge to work with the carb.
Now a dual plane has the "best" of both worlds. It can keep low end torque and feed enough air up high for normal street driving.

Now came EFI. I does not relie on engine intake velocity (vacuum) to meter and atomize the fuel. So you can use an intake (single plane) to increase your airflow without many adverse affects on low end torque

The above is a very simplified explanation, there are many other differences. I'm sure out left out a few ones, but you could talk about this kind of stuff for hours. But that is the gist of it. Hope I confused you a little. I could have explained it alot better than I did, but I am way too lazy to go back and retype anything!

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Jerry

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89 RS Lt Blue T-Tops T5
355 Crate, Compucam 2040
Pst Front Hotchkis Rear
Edle. TES 3" Flowmaster
Harwood hood, bla, bla, bla...
94 Z28, LT1 6M, Black
Most of the bolt-ons
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[This message has been edited by 89RS355 (edited January 28, 2001).]

 

Thanks for clearing that up, i'm beginning to understand this now.