I'll chime in here... And I have said precious little here, but I'm back in country now... Anyway...
The way a j pipe operates is frequency cancellation, Ie, it's designed and created to target a very specific frequency of sound in Hertz that our ears perceive as drone... So it's very vehicle and mod specific. The sound of the exhaust pulse enters the section of the "j" and as it bounces back colliding with its counterpart and cancels out... The maths is sound, and it does work. This allows you to target the exact drone point that bothers you most... Say you commute to work and spend most time at highway speed, you target that... Or have a family wagon and live on a hill... You get the point.
Also to note that the resonate frequency of things around will also effect... That's why we all would agree that the Wagons are all droney...as the floor becomes a sound board and plays more havoc than Rolf Harris at a kids concert (not Ment to offend, sorry). You get the idea...
So... If someone was to experiment enough with their own pipes, they could, in effect, cancel the drone of the vehicle, and at that point we would not hear the drone, and the floor and length of pipe and what not else would not hit our ears and we would not get a headache from hearing it after a while like we all do...
I'm not saying stay with the j pipe setup for your application.... I'm saying dont just discount the pipes as no good, it's just not targeting your specific freqs of drone... Which Really Sucks, especially after you went that way expecting it to workout for you...
It can if you want to experiment with different lengths, and usually you have a lot of movement with the caps in a decent j pipe product, which is good because it costs nothing to put the caps at the longest setting and tap them in untill you have no drone in your setup. Usually they do that cos one vehicle has extractors one doesn't, ect .... If you have exhausted the "adjustment" and still have drone, that's when I'd be changing...
Let me know what you think and what you decide to do, as I'm interested to see how it pans out
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