Ok heres the breakdown.. This is my setup and the problems im having:

B18A Block
Jdm ITR Pistons
Shotpeened Ls rods
Micropolished crank
Gsr oil pump
Gsr water pump
arp rod bolts
01 Gsr Cyl. Head
Pr4 Ecu
Summit Rpm activated switch
Apexi AFC

Ok heres the problem.
When I take the car into Vtec, which is set at 4400.. it feels like it has like a hold on it then it like pulls like crazy at about 6K. So basically its breaking up or just completly loosing the power between 4400 and 6K. but in every gear its the same rpms. even when I take it into vtec slow it like doesnt open up clearly like it should, its sounds all crackly and you can feel it in the car. I think its the RPM switch but i didnt think it would be a problem since i have the afc and i have it richened out through vtec. If anyone has had the same problem let me know of if anyone knows what it could be let me know. thanks alot. -Ben