Problem exhaust drone: Solution 1/4 wave, or Helmholtz resonator?

[oldeskewltoy]

Problem: engine drone 3500-4000, it is quite bad through that zone, so lets say 3750 rpm + or - 250 rpm.


I've been doing some research into side branch or 1/4 wave resonators - closed "J" shaped pipe of SPECIFIC length added to the system.





Some people also use Helmholtz resonators (pipe leading into closed muffler)




Each of these has their own formula (no, I have not researched each's formula yet) The reason I have not checked into both thoroughly yet is packaging of a Helmholtz resonator, and placing which ever device in as optimal a location** as possible - close to the source/engine.




So based on optimal placement, I was thinking of tapping into the very beginning of my Brave exhaust with a 1.50-1.75" diameter pipe, and running it the prescribed/calculated length back....




Initial distance is around 30"... or so I was told. I don't trust this - I'd prefer YOUR help with calculations...

So what length pipe do I need to target 3750 rpm??