The other day i was installing a test pipe on my otherwise stock exhaust system and i noticed something rather strange looking... This is the first time i have been underneath my car, since i have only had it for a month...

After the cat, but before the resonator, there is a pipe that shoots off the main exhaust pipe, looks similar to what would be an H pipe if there was a parallel exhaust pipe for it to connect to...

What is the function of this otherwise useless looking pipe... to me it seems like it would only slow down the exhaust stream, for it doesnt connect to anything...

thanks in advance.. hopefully this doesnt sound too newbie-ish...

 

That would be the helmholtz tube. It is usually present on exhausts to reduce noise. For example:

8BALL's exhaust
rehile's exhaust

Some people do a "resonator-ectomy" to increase some raw sounds.
- see local post1
- local post2

 

So how do you like your new test pipe?

 

i actually just put in a test pipe with stock exhaust too. its not too much louder, but the whole system cools down a lot quicker than with the cat. what other mods do you (b18-mike) have?

 

it doesnt sound too bad.. a little raspier than before... definitely happy with the 100 dollar investment... as of right now i am bone stock, other than the test pipe, (and a few other random things, springs, lip)... definitely looking to do gears or a header in the near future...

edit : would it be beneficial or worth it to get the helmholtz resonator and the other resonator cut out and a straight pipe welded in? im looking to make the exhaust a little louder and more free flowing? i like the looks and the sounds of the stock mufflers, just wish it was a little louder..

 

[QUOTE=b18-Mike,Jun 24 2007, 12:34 AM]

edit : would it be beneficial or worth it to get the helmholtz resonator and the other resonator cut out and a straight pipe welded in?

 

You removed the square box one? ^^

 

Do you notice any difference in the performance, or just the sound?

 

A Honda that sounds like a Nissan - it's a Honda Schizo

 

Pete had this done to his car am I was really amazed at the tone difference. Probably the better bang for the buck mod to the OEM exhaust. Changing the Heimholtz tube will alter the drone and engine compression noises you will hear in the cabin.