tooter's manifold adventure...

[tooter]

Originally Posted by Bluevitz-rs

Cool Tooter! Are you reworking the manifold with your own plenum and TB mount?

Yes.

I have a totally "outside the box" idea and am going to build up a tooter and dyno it just to see how the concept works.

[tooter]

The new plenum came today, and it has nothing to do with intake manifolds. It's a structural architectural ornament. This is the basic layout of the experimental tooter...













I filled up both plenums with water to test the volume, and was totally suprised to discover that they both hold exactly 26 ounces! I'm always looking for omens and this is a really good one...



The old plenum appears to be a lot larger because there is so much material inside it which by displacement decreases the volume.

[cali yaris]

Phallic!

[tooter]

To you, everything is phallic.

[CrankyOldMan]

Hmm, what about the 6" tube remnant?

[tooter]

It's right here...



I think I'll try it without this time since the two plenum volumes already match. I can always cut off the hemisphere and add a ring later. And while the plenum is off I can clean up and smooth out the runner entrances.

[CrankyOldMan]

Originally Posted by tooter

And while the plenum is off I can clean up and smooth out the runner entrances.

Yikes, those are some gnarly welds for a flow surface.

Thinking back to my own can-shaped design, the flow analysis showed that there was pretty much no air movement in the shoulder area of the TB side.

[tooter]

Well, remember that it was just a mass produced Corolla manifold and not a high performance racing component. The welds are actually well controlled, but I do think I can improve the runner ports with the trusty old Dremel... something that no manufacturer would take the time to do because there's no return on investment.

[malibuguy]

they welded them like that for easy access & it smooths out the lip that would be there if they were externally welded

[xnamerxx]

^ that and it would be next to impossible to weld them externally.

[JustDidIt]

Interesting... whats the next step??

[malibuguy]

Originally Posted by JustDidIt

Interesting... whats the next step??

procharger

[tooter]

Originally Posted by JustDidIt

Interesting... whats the next step??

I don't exactly know just yet... I'm thinking about it while finishing another regular tooter.

For sure, I'll need to have a plain throttle body base plate made and figure out a way to attach it securely as the aluminium hemisphere shell is pretty thin. I was thinking of a short bellmouth on the inside like this extending a couple of inches into the center of the hemisphere directly aligned with the axis of the 4 runners so the flow is a straight line.



The throttle plate will use the same CNC information for the outer surface minus all of the adaption machining. It'll be one inch thick to raise the throttle body enough for the chip to clear the hemisphere.



Here a flow simulation for a bell mouth...

http://www.youtube.com/watch?v=jFwo_3IxZyo

If it works one way... it'll also work the other.

[Bluevitz-rs]

P.S. Tooter, you can clip that wire screen out of the gasket. Someone here flow benched a TB with and without it and it just causes restriction.

[tooter]

Originally Posted by Bluevitz-rs

P.S. Tooter, you can clip that wire screen out of the gasket. Someone here flow benched a TB with and without it and it just causes restriction.

How many cfm difference did it make at WOT?

I was told that the screen helps to break up the positive crankcase venting oil fumes. Whenever a manufacturer makes a more expensive casting to fit a more expensive part, they have a good reason to do it.

[Bluevitz-rs]

If you were at all concerned about emissions you would have left the stock airbox in with the charcoal pre-filter. But no, that screen is there to make the air turbulent as it enters the stock plastic intake manifold.

[tooter]

Originally Posted by Bluevitz-rs

If you were at all concerned about emissions you would have left the stock airbox in with the charcoal pre-filter. But no, that screen is there to make the air turbulent as it enters the stock plastic intake manifold.

Hey Blue... take a look at this flow simulation.

http://www.youtube.com/watch?v=WzWsUB79e-A

And look at this one that shows the difference in the timing of the air flow past each side of the butterfly...

http://www.youtube.com/watch?v=k-MN6igceog

Notice how the flow on the backside of the butterfly is way more turbulent than the tipped in side. This means that the screen actually helps to stabilize the turbulence the back side.

The person who did the flow testing must have had an instrument that generated a numerical comparison. Do you know how much cubic feet per minute that difference was?

Here's another one showing what happens on the backside of a butterfly in the flat position...

http://www.youtube.com/watch?v=0z_hFZx7qvE

A screen would help to stabilize the flow by breaking up those rotating eddys.

I've watched a lot of these simulations over and over again to help me to understand the dynamics of flow. It's totally fascinating.

[Bluevitz-rs]

I think it it was only a cfm more but didn't know about the airflow thing. Maybe it's better to leave it in then. I guess it's more of a part throttle thing than full throttle.