i notic while cleaning my gsr intake manifold that i has what looks like a throtle body in each port? i read in a book a little about it but didnt understand. can sum 1 explain the theory behind this and whether or not it should be replaed for something better

 

IAB = Intake-Air Bypass system.

The long runners give more power at lower rpm, because of the pressure pulses reflecting back from the plenum. At high rpm, the secondary (short) runners open up, giving more air flow at high rpm.

I think the secondaries open up at about 5700 rpm, but it also depends on throttle position.

 

does this help in the higher rpms or is there a better intake

 

There's probably better intakes (ITR, Skunk??) if you only care about high rpms. But they aren't to swift at low rpms so drivability suffers.