i did some testing .. on ohm test (digital 0.0000 readings)...
Nology
OEM
Bosch
which i tried b4
They are only a slight fraction .. not much Nology won. i'm not sure wether a fraction of 0.0000 do much or not.

Low torque rpm is not coz of leads...
leads works good at top rpm as they can deliver more spark a peak (brochures say lol)

might be your exhaust doesnt have enough back flow ... whats the diameter of the exhaust any way? did you change the pipe?