Pics Inside the variable flow Intake Manifold
In addition to the engine and exhaust pictures, I was able to get a real good look at the inside "magic" of the 1UZ-FE VvTi variable runner intake manifold.
WOW, the inside looks like a trick Ferrari intake.
The intake is in 2 major pieces. The bottom half bolts to the heads and contains most of the plenum area. The front edge makes up 1/2 of the throttle body hole. Air enters the manifold through the throttle body and enters the plenum area which is a large open area. The air then flows down through the bottom plenum area and then up through the 8 inner runners.
If you visualize the air coming in from the front (the bottom of this photo) it fills the center "trough" area (plenum). Look at the bottom left of the plenum, this feeds the runner hole on the lower left and meets with its matching runner in the upper half shown below.
WOW, the inside looks like a trick Ferrari intake.
The intake is in 2 major pieces. The bottom half bolts to the heads and contains most of the plenum area. The front edge makes up 1/2 of the throttle body hole. Air enters the manifold through the throttle body and enters the plenum area which is a large open area. The air then flows down through the bottom plenum area and then up through the 8 inner runners.
If you visualize the air coming in from the front (the bottom of this photo) it fills the center "trough" area (plenum). Look at the bottom left of the plenum, this feeds the runner hole on the lower left and meets with its matching runner in the upper half shown below.
Last edited by JBrady; Jan 12, 2003 at 11:33 PM.
From the inner 8 runner holes in the lower intake the air flows into the 8 inner holes in the upper intake. See the super "trick" set of 8 throttle bodies lining the top of the upper intake plenum. In this picture they are closed.
The inner runners flow up and over and down to the outside holes. These feed the outer holes on the lower intake that go directly into the heads.
The inner runners flow up and over and down to the outside holes. These feed the outer holes on the lower intake that go directly into the heads.
The above picture shows the inner 8 TBs (throttle bodies) closed. This is how it runs from idle up to over 4000rpm. This "tunes" the intake with long runners. This promotes good inertia and enhances low to mid speed torque. At higher rpm, 4500rpm or so (I haven't found the specs on the opening rpm) the 8 TBs open. This effectively "shortens" each runner by about half. The shorter runner is tuned better for high RPM power and the port is feed by a larger total area improving its flow ability.
TBs Open:
TBs Open:
Here is a side view of the upper intake. You can see the half hole for the main throttle body. If you look for the inner runner hole on the left by my hand, follow it up and over the top and down to the outer runner hole on the right. The high speed TB in the middle cuts the lenght in half when it opens.
Old thread yes... but thought I would add some more pictures:
Here is the lower intake from the back. You can see how the runners feed the cylinders almost vertically (near optimal). The lower part of the throttle body inlet (half a circle) can be seen at the front if you look closely. The area in the middle is the plenum. From the plenum the air goes to the runner inlets below and flow upward into the upper manifold through the inner 2 rows of ports. Of course once the secondary throttles open the runner becomes effectively shorter and there is less internal friction presented to the air flow.
Here is the lower intake from the back. You can see how the runners feed the cylinders almost vertically (near optimal). The lower part of the throttle body inlet (half a circle) can be seen at the front if you look closely. The area in the middle is the plenum. From the plenum the air goes to the runner inlets below and flow upward into the upper manifold through the inner 2 rows of ports. Of course once the secondary throttles open the runner becomes effectively shorter and there is less internal friction presented to the air flow.
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Is getting to this difficult? I am always up for cleaning whatever I can in my car, as the previous owners didn't exactly do so
. Anyways, Whats the easiest was to get to a core part of my engine?
. Anyways, Whats the easiest was to get to a core part of my engine?
Aside from this manifold, do you think the heads are configured differently from the non--VVT-i variant?
I suspect that the complexity of this engiine would be better suited for a transplant with harness. <shrug>
Drop a VVT-i, your headers and exhaust into a first gen and it could be some kicks.
I suspect that the complexity of this engiine would be better suited for a transplant with harness. <shrug>
Drop a VVT-i, your headers and exhaust into a first gen and it could be some kicks.
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So are u a mechanic? Great pics by the way.

