helmholtz chamber vs popping tune?
 

Hi fellows, i was looking into this video about welding a j pipe/helmholtz chamber to counter my exhause drones-
https://youtu.be/z5SY5oUTEcc
the thing with my brz is it's on flashtablet's stage 2 plus with a backfire/popping custom tune.
it's great fun with the poppings of cos.
I'm wondering if adding a j pipe will affect the popping since the exhaust gas will have more pipes to go through and explode in the closed end of j pipe possibly or not? :confused0068:
wonder if anyone tried this 2 mods together??

There should be no issue with doing this. The J-Pipe is what we have done for drone and if you calculation on size and length are correct, it works very well. No exhaust actually travels through the J-Pipe tube because it's capped. So, it should have little-to-no effect on your pops.

Before other comments come in about your P/B tune, all I'm going to say is that if you're trying to reduce drone, you should probably try to upgrade our exhaust hangers for JDM ones, switch to OEM front pipe, or upgrade to a double resonated one.

What is your complete exhaust setup?

thanks for the reply!
following that youtube video my calculation for the length of j pipe to be 47 inches, i doubt if i have that much space underneath the car haha

i am on psr uel header and perrin 2.5 resonated exhaust.
front pipe is stock.
exhaust hanger upgraded to oem sti ones, it does help to tone down the drone, i will say about 30 percent, still has substantial drone from 2k to 2.6k rpm.

Alright, seems like you should have everything to tone down some noise. The JDM ones are a popular choice which I also have too. Haven't really much info on STi ones but before doing any weld work, a cheaper route would be getting the JDM ones. May be some on Ebay because ordering from Nengun or equivalent takes about a month.

they are jdm. part number 44066AJ010

No problem!

There are other calculators out there. You can trade diameter for length if need be.

May want to try sound deadening the trunk area, and under the rear seats.



You really have a setup that shouldn't really drone that much, possibly may be quieter with a nvidia q300 or a hks legamax or something with a bigger suitcase style muffler.

My nameless with a catless uel never droned so the perrin must be louder than others with mufflers

really where did u find those calculation? i only see people saying get the j pipe same diameter as the connecting exhaust pipe works the best

for the same exhaust, people seems to have all sorts of experience. i searched and see lots of posts about perrin having drones at our platform despite more users comment them as 'zero drone'.
every car is made slightly different i guess.
looking at the bright side, at least i am hearing less of the random rattles in my brz haha

It doesn't need to be the same size. It can be smaller, or a tube with a dead end can on it.

Here's one from a quick google search...

https://www.omnicalculator.com/physi...oltz-resonator