as a general rule, pipe diameters of more than 2.5" are only effective for cars with forced induction. as mazdax2 said, you will feel some torque (arangkada) loss if you put this stuff on a N/A car.

while installing an intake is very easy, installing headers/downpipe/exhaust is not for beginners. you'll definitely need power tools, a lift, and maybe even welding/cutting equipment depending on your car's stock parts.

on a 1.6, i wouldn't expect gains of more than 15-20 hp - and that's if all the parts work perfectly with each other