This was a freshly completed build last summer, and although I did put a bunch of miles on it, it was mostly tuning the fuel injection. Haven't had it on a dyno yet, but would like to soon. It shouldn't effect horsepower at all since only sound waves travel back and forth through the resonator. Seat of the pants, it feels the same.Did you ever put it on a dyno to see if it effected the HP?
This is an inexpensive compact way to reduce the drone. Nice job.
The slip joints make it easy to tune.
The system used to reinforce the chassis looks professionally done. Was this a kit or custom built?
I never thought of checking decibels before and after. I do know it's a huge difference. Before, I couldn't stand it more than 20-30 minutes. Now, it gets really quiet inside the car when cruising at the effected rpms.OP - did you measure the DB drop in that annoying freq range? I'd be curious how much it dropped w/ 2 1/2" pipe, since chamber volume will impact attenuation as well.