LT1 intake question

[sled_dog]

Got mine today

What is the port between(and below) the two throttle ports? Its got a passage like into the base of the intake. Is this where the EGR recirculates?

 

[dyeager535]

Where's EGR mount on the intake? (could check Millicans site I guess )

TPI intakes have holes cast into the very center of each runner in the base for EGR.

How about IAC passage, or PCV?

On TPI, IIRC, PCV is pulled straight in behind the throttle body, (or at least behind the blades) and EVAP is restricted somehow, perhaps a smaller port.

 

[sled_dog]

throttle body setup is the same between TPI and LT1 as far as I can figure. The EGR mounts to the back of the intake manifold. Like a Vortec truck it gets ducted out of an exhaust pipe(manifold or down pipe) and into the EGR. I can't see where else the EGR would come in other than to travel under the intake and go in through that hole. I'm not using EGR, just curious what this is.

 

[dyeager535]

Never had my throttle body off the plenum, so no idea how the passages work. To check EGR, if you can put your mouth over it (or use compressed air) blow into the passage and see where they come out. Could do the same on the TB.

 

[Lonnie P]

The hole between the 2 throttle blades is the idle air control port. It feeds through passages to each individual intake port (a small 3/16" hole near the cylinder head) This was done to provide equal air to each cylinder. The threaded port below is for the PCV valve. This enters the same passages as does the EGR.

TPI & LT1 t-bodies are different (linkage & IAC type) but will physically bolt on.