My car with the same exhaust system other than having long tubes (and Ultra-Flos which should be worse than super turbos) had more drone noticeable with the TTI turn-downs on it. I eventually cut them off and went with some tips that stick about an inch past the bumper and its a lot more bearable. I think those TTI turndowns cause some "drumming" under the car.
Originally Posted By Neil
Could you temporarily try taking the turn down tips off just to see if they are causing it?
I once had a car with full length exhaust exiting into exhaust tips that ran parallel with the ground exiting under the rear valance and never had a drone issue at any rpm. It had Hooker Aero Chambers and 2.5" pipe start to finish.
I will try that soon. Tomorrow I should have some time to play with the car and it shouldn't be raining. I'm going to start by attempting to dent the header as that needs to be done regardless. Afterwards I'll take a look at the tips. IIRC, they should only be held on by exhaust clamps, if they're welded on, I may just go with some circular resonator past the muffler.
