Roll out the marching band the drone is dead finally!
I had dyno torque the chaps who build driftworks cars weld me some silencers into the back end of the invidia and its spot on now even with de cats
They have totally killed the drone around 2/3000rpm and knocked all the rasp out of the system since fitting de cats.
I sounds less race car now tho which I'm kind of sad about but I think it will so much easier to live with on a whole.