Whats the center intake hole for?

[staticc]

i noticed when i changed my fuel injectors, and had my upper intake off..

thats theres the 8 Runners, and a smaller hole in the center? and my GT40 intake had a runner for it and it loops around to where the throttle body connects.... but, whoever owned it before me, put a 1"? spacer in there. and the spacer blocked off that center hole. i ended up putting the spacer back in on the reinstall. but im curious

what does this do? anything worth while?

i found a picture of a trickflow heat spacer. but this one DOES have the center hole that im talking about. here

 

[Warbird19]

its for the EGT goes up to the throttle body and warmes it up for emissions. i blocked mine when i put my trick flow intake on. the felpro 1250 comes with the blockers.

 

[Michael Yount]

The center hole is for the EGR system - exhaust gas recirculation. Exhaust comes from the heads, into the lower, passes through that hole to the upper, goes through the upper into the egr spacer where the egr valve allows a certain amount of exhaust into the intake stream under part throttle conditions. The egr valve doesn't allow any exhaust into the intake at idle or at wide open throttle. A little exhaust in the intake stream cools the combustion chamber allowing more timing to be run -- results in better fuel mileage and reduced emissions.