Fancy Tech: How to Get Rid of Exhaust Drone, works great!

MoulaZ

That's great for you... but not for the loads of people who've commented and contributed to this thread.

On topic, happend to come across an article regarding using 1/4 wave tubes to tune out certain frequencies in Diesel engines but the concept is transferable here. Kind of annoyed I didin't think of it before coming across this paper.

Rather then asking a shop to tack on a tube with a clamp system to vary the length of the tube, work with the shop to tack on the longest, open-ended, straight tube you can manage... and fab up a resonably thick disc to act as a piston to vary the internal length of the pipe to alter it's resonant frequency. The piston would have a rod attached at the end of it to push in or pull out, that can be extended or shortened... surely can't be all that difficult to extend, even temporarily as it's only for tuning purposes.

Once you've settled on an ideal length, mark it, take it back to the shop and get them to cut it down and weld an end cap on.

Personally, I'm going to have 2x 39 inch pipes put in and work my way down. This'll allow me to try negating as low as 100hz drone.

Attached Images

Piston QWT.jpg (80.7 KB, 48 views)