what the.... I thought the B18c1 butterflies flew open at high speeds to supply big fat air to the plenums and intake ports. Now I'm told they do the opposite? They are open until the high end and then shut close? Right when short fat quick lines of air are needed? Like the Type R manifold that has the short fat plenums.
Can someone explain? I have been lightly massaging the upper roots in the intake chamber but if the fat tubes are going to be cut off at high RPM's why not just extract them? What the... why are they .....why I otta....why I... POW ZOOM TO THE MOON, ALICE!!!!!!

 

Because you were right at first, then some moron told you otherwise h:

Don't listen to that person ever again... they lie hfawk:

 

Ok there are 2 sets of runners in the GSR manifold: long and skinny, short and fat. During normal driving, the long/skinny runners are used to create midrange torque...the butterfly valve is closed over the short/fat runners. Once you hit 5800 the valve opens, and air is routed to the short/fat runners for max power.

 

Maybe someone's confused, talking about the solenoid valve which operates the butterflies... At low rpm the solenoid valve is open, causing vacuum to pull the butterflies shut.

 

hello all, man that was a close call!!! I couldn't imagine the butterflies closing at higher RPMs. It didn't make any sense. I am attempting to get better flow in the plenum farthest from the throttle body. When I extracted the valve train the intake valves for this plenum showed evidence of fuel dropping from the vapor stream too early. When I shot water down each plenum the other runners caused twisting streams of water. The farthest plenum had a weak jumbled confused pitter/patter stream of water. Looks like there is about 3 line of sight turns in the plenum alone. The stream probably gets jumbled by hitting one of these curves too hard and angling back crashing into the mid-stream. So the velocity is negated (like cancelling a wave by sending a wave back against it?). Prob. why the fuel is not making it to the chamber?
I thank all for confirming what has to be common sense to an O2 molecule.

 

The #1 cylinder usually gets robbed of air since the other three cylinders are positioned before it and the stock plenum's shape doesn't help for the air flow. The skunk 2 and other aftermarket manifolds have solved this by the shape of the plenum to ensure that all cylinders get all the air they need by using the physics of the wave you are describing.

And about the butterflies. The air is bypassed to the long runners running along the top of the manifold before activated by vtec. Then, when activated, the short runners and the longer ones used before are both open for air to pass through. The short runners acheive high power under high RPMs and the longer runners acheive "high" torque under low RPMs.

 

I want to thank epoch, master yodub, jim blake, and shmoo for solid responses. I sent my throttle body and intake chamber out to be bored and matched. I am still working on the plenums. I cannot seem to polish the deep pocket just past the butterflies. I am grinding the 2 outside plenums on the inside wall. I am widening apprx 1 mm. I know I am compromising velocity but I want to try to straighten the flow - even a miniscule straightening is acceptable to me. I will also be going after the domes of the butterfly plenum openings and I am grinding the domes of the tiny runners. The weld/ manufacturing lines have been irradicated.
Has anyone enlarged the dome openings of the long runners? I am thinking of putting "pea shooter" grind in the middle of all 4 domes - through all 3 bodies. I'll match up all three bodies and lay a drill bit across the dome and let it grind the width of the drill bit. It will make a force like when you are in your airline seat and the dam air valve above is broken and the air keeps hitting you in the ear and then when the plane lands you drink scotch whyskey waiting for a ride that ain't commin and then finally she shows up and says she went to the wrong terminal and hands you the keys and says "I'm tired, I need you to drive." 1/2 way home she wakes from a nap and says we need to go meet some of her girls at a bar 10 miles out of the way, into the night you fly.
Then when you nod out at the bar she complains you don't respect her friends.
Righttt.

Now, I'm in South F. L. A. grinding on a B18C1 intake manifold. Good therapy.
Thanks to all.

 

:werd:

Also some OEM honda manifolds are biased to the #3 cylinder for some reason...possibly it's the fluid dynamics of the air rushing into the plenum at high velocity. I wish I could see the airflow inside one somehow at WOT and high RPM.

 

:screwy:

:rofl: That is the most random thing I think I have ever heard. What do you smoke? I want some....