Borla Borla drone fix?

[walkerb]

My 05 AC has a Borla catback dual system that exits under the rear bumper. To reduce/eliminate the 2200 rpm drone, I am serious about adding a 4X8X13 Borla universal muffler (40981) between the Toyota resonator and the Borla cat back. Since the 'add in' has a straight through tube the same size as the tubing it's replacing I see no back pressure increase, so performance should be unchanged. Any opinions on what this will do for drone, sound, etc.? Your comments please.

[walkerb]

Installed the Borla 4X8X13 (#40981) between the Tundra resonator & Borla cat-back system. Good news & bad news. The good news is the 2000/2300 rpm drone is reduced by estimated 70%. Bad news is - so is the overall exhaust sound. Quieter at idle and thru the shifts - but when you stand on it the sound comes back very robust. No reduction in performance.

[Agent WD-40]

You could try changing the length of the pipes. That would change the resonant RPM. If you do a google search you can find more specific info on how to calculate what length of pipe will shift the resonance to what RPM.

[walkerb]

The extra muffler took care of my drone concerns. Barely present at 2000-2400 rpm. Overall it's quieter, but still has authority when pressed hard. Likely it's not what everyone wants, but if the drone is an issue, the extra muffler knocks it down while still keeping some of the Borla sound.