gravedigger472

i just got my Weiand Team-G intake in the mail from my father. i am still not sure there is a even consensus on here or on FSC about weather a single plane or a dual plane is better, but that's not what this is about. its about plenum volume. Im going to use this manifold at first and if i want to later im gonna change it. but for now, its single plane time.

i know that more volume is better, but where do diminishing returns apply? im sure that there is no straightforward answer to this, but ill try and ans anyways.

the intake that i have has a large area above the runners that some do not have. (mine is on top) Im wondering if i would benefit or sacrifice performance with the shorter plenum



look at the difference, how much taller mine is.



would it be of any benefit to me to machine down the upper plenum to the level of that in the bottom pic? maybe 1/2 inch above the tops of the runners? i will sacrifice a little plenum volume but still have alot. any thoughts??

EDIT: i can safely remove up to about 1.75 in of height, which translates into about 22.58in^3 of lost volume.

also, these are the specs of the engine im putting together:

1989 K2500 ECSB
350 4 bolt, bottom end freshened up
210/220@.050cam
ported swirl port hears
team-G intake (see above)
RBOB's EBL
bored TB and higher pressure on stock injectors
headers, y-pipe, no cat, etc...

gravedigger472

the too large plenum will caise delayed throttle response (right?)
but how large is too large? and what is too small? I would think that the 7531 weiand might be on the large side for me, but who knows.??

RBob

iTrader: (1)

You are going to hate that manifold in cold weather. The main issue is that it is an AirGap design, which has no provisions for heat under the plenum.

If you decide to reduce the plenum size I would cut the upper portion off. Then mill that piece flat and keep it as a spacer. Then mill the top of the intake properly for the required angle and make it flat.

You can then easily swap the spacer in & out to see what kind of difference in performance it makes. Some engines like a larger plenum while others do not.

But back to the cold weather, if you plan to drive the vehicle in cold weather as your other thread suggests. I would provide a method of adding heat to the bottom of the plenum. It could be as simple as a coil of 3/8" copper tubing epoxied to the plenum. Then run the engine coolant through it.

RBob.

radical82

Manifold selection really depends a lot on the rest of the engine, how much heads and cam you're running....On a more stock type engine operating normally below 6500 rpm, you're going to be giving away a lot of performance with all that volume.... Unless you have an engine that is going to require all that volume, then the flow charachteristics of the intake and heads should be a bigger concern... Generally a single plane intake with that much height is going to work best in the 3500 to 7500 rpm range, a bit impractical for the street....

Another general statement on single plane intakes is that a taller plenum (on an engine that can use a single plane) will add a bit of bottom end.... I've used the shorter version of the same intake on big inch small blocks with great performance from the 3300rpm range and up---this with a solid roller and 210cc heads....

gravedigger472

both a very good idea, i will have to try them. and as far as the manifold working or not..... well its free and i want to try it. if I cannot live with it, or cant get it working right in the winter, well ill buy another and put it on. but i at least want to try it.

Saabster

iTrader: (2)

I don't see how you're going to close the hood with a manifold that high.

gravedigger472

well i just went out and did some quick measurements and if i mill the intake to the height i described, its within .25" from the stock one. so push come to shove, i can make it fit.