I have an intake manifold that if for a weber IDF downdroft carb. I'm not sure who makes the manifold, but I have heard that it is from redline performance.



Anyways, the design of this manifold confuses me. The intake ports for the intermediate housing are connected. As in, the 2 barrels from the carb get split up 3 ways and there is basically one runner for the intermediate housings intake ports, and a runner for the front and rear intake ports. That center runner is not divided and where the intake bolts to the engine, there is a big rectangle port.



kinda like this:







What kind of performance loss do you guys think I am losing because of this? All the IDA style manifolds I have seen keep the #1 and #2 rotor runners separate (seems to make more sence). There has to be a massive amount of intake reversion going on in that center runner.



Any thoughts?