I have a Xcessive lower manifold and i am thinking of running two 850's in the center and two 1600's on the outside. since the fuel rail already has 4 spots and i was just going to block off the lower primary rail. do you think it would be a good idea?? all i am worried about is if idle will be effected? any thoughts

 

The primaries are located so close to the combustion chamber for response. The further the injectors, the less the response, but the higher the overall power.

I am just running stock primaries and 4 secondaries. Allows you to run smaller secondaries and also have fuel being injected into each runner under boost. In my logic, I would think you could achieve better atomization with the 4 secondary injectors method too.