At first I really enjoyed the sound from the outside, however am I the only one who has one that thinks it's way too loud in the inside? Any ideas to lower the exhaust tone inside the cabin?

 

Nope, you are not the only one.
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Post #5


Yes but I am not sure if it will work (I'm confident that it will though) and it may seem ghetto. Ask a muffler shop to extend the piping past the rear bumper. I believe the exhaust tip stops too soon under the bumper, which causes the exhaust note to be loud in the rear cabin. I did this on an old turbocharged Subaru RX (1989 - *Scrappy*) that I had and it worked. Just a thought!
Here's an old link of a few pics I had of it when I had the turbo changed out and a shop exhaust put in. You can see in one of the pics how the piping comes out in the back. This was done to take away the noise it previously had when it was shorter.
Subaru RX Turbo Dyno


Some may suggest a pre-muffler in the B-pipe (but why when you could've just purchased a muffler).
Some may suggest adding sound deadening in the trunk area (Spare tire area). But from reading on the net in several forums, it doesn't help a whole lot.
Some may suggest adding a 'silencer' in the tip of the pulse chamber piping. It will affect your freer flowing exhaust flow though.

 

Thanks for all the info guys, I'm gonna try this out for a week and see how much I can tolerate it, but from the sounds of things I may just go back to the stock muffler.

 

Yeah, it resonates like mad.

Fact is, it is not a muffler. It's basically a straight pipe on a four cylinder, and the four cylinder factor is a big part of it. Drone is what they do.

I really like the way it sounds, especially passing through an underpass and stuff but there are times (like after a stressful workday) when the drone is too much to tolerate.

If it gets to the point where it has to be modified or extended to make it work, I'm pulling it. I could just as easily have a shop fab a whole straight pipe from the flange back. It would probably be easier than cutting this thing up to change it around.



I'm thinking about wrapping it w/ header tape to see if that helps. I'd love to find a way to keep the thing and eliminate the drone.

 

cut your stock b pipe and install a bigger/longer resonator to change the drone frequency. Wrapping with header tape doesn't change the exhaust not. OEM applications bolt on weights with rubber to absorb the vibration and change the hertz to an acceptable level.

 

Yeah, but wrapping the Bisi pipe is a cheap, easy experiment. I'm thinking it could dampen it a bit, as well as change (increase?) the exhaust temp, which could effect the velocity/ frequency.

I also thought about putting some steel wool in the Bisi Helmholtz tube to alter the resonance frequency.

I also thought about cutting the helmholtz tube in the middle, adding some tubing and a hose clamp so I could slide adjust the length like a trombone. The will alter the frequency the tube cancels