Flowmaster AT catback drone HELP

[wfydaniel1990]

Originally Posted by KillboyPowerhead

From what I've read j-pipes don't affect gas flow or sound (from the tail pipes) at all. The way they work is: a certain frequency range of sound waves causes drone, and the j-pipes are capped at the end which causes the sound waves to bounce back and cancel each other, thereby eliminating them and the drone.

The frequency of the sound waves that cause drone can differ with different exhaust piping, and there is likely a range for a few hundred RPM where the drone occurs, so by having adjustable j-pipes (like from Solo) you can "tune" them to what you need for your particular setup. If you can't get adjustable ones, you'll likely need about 36" long j-pipes for this car. I have my j-pipes as long as possible (about 1/16" from contacting something in either direction) and there is still a bit of drone, but it's reduced by about 90% or so I'd say.

much appreciated ！ i've already contacted one of the local exhaust manufacturer to make 2 j-pipes , hope they'll work . i'll come back with good news.