Ravskau

I finally got a chance to walk up under my car while it was up on the rack swapping out mufflers. (was gonna so the single conversion but
decided to go with just replacing the factory mufflers with MagnaFlow
14822's) In between the cat and the resonator there was a little stub of pipe that stuck out about 5 inches. Does anyone know what this things purpose is??? Or is it just a mechanical appendix?

SteveUCI

I believe that's the "resonator". I wish I knew the physics behind what it actually does.

Vtecnrg

I was told that it makes the pipes quieter.

twohoos

It's a tuning stub, used to alter the sound of the exhaust. The length and position of the stub determine which revs it affects.

Although I can't know for sure, I'd assume that Honda found that certain rpms were producing too "boomy" a sound, and inserted this stub to compensate. Think of it as a rudimentary "graphic equalizer" for the exhaust.

SteveUCI

[QUOTE]Originally posted by twohoos
[B]It's a tuning stub, used to alter the sound of the exhaust.

drjekyll2000

I may not be an accoustical engineer, but I did stay at a Holiday In Express last night... lol Actually, I have a degree in physics so maybe I can help. (I'm not going to explain the physics here, but most people with an engineering or science background could correct me where I screw this up) But in the same way that only certain standing waves can travel along a piece of rope, only certain sound waves will stay in this pipe. It works in a similar way on brass musical instruments. What this pipe does (IF IT IS IN FACT AN ACCOUSTICAL PIECE, and not something to help performance) is that it absorbs sound waves that "fit" into the chamber. I have not seen the chamber, but given what I have heard about it sounds like it would absorb between 3000-5000 Hz (the approximate frequencies that would fit into a 5" pipe), which would lessen the midrange sound common in a lot of import cars. Elimination of these kind of frequencies would give the 2000 a more throaty growl.

Of course I could be wrong
-Spoon

boltonblue

technically the exhaust system is a transmission line. the exhaust gasses flow down the pipe like waves. Depending on the exhaust parameters, the wave will dissipate when it hits the end of the pipe or a portion of the wave will be reflective back up the pipe. For any given frequency the pipe can be adjusted maximize or minimize the amount reflected wave energy. This is known as the resonance of the pipe. The frequency of the wave is based largely ( but not exclusively) on engine RPM. But the engine has a wide range of "frequencies" especially the S2000 with a rev range from 1500-9000. Adjusting the resonance point controls the effectiveness of the exhaust and consequently performance. By putting in the "appendix" the engineers are moving about the resonance point. They may also be adjusting the exhaust load to smooth out engine torque and make for a more tractable engine.

BTW they actually play the same game on the intake side of the engine. That's why they spend so much time on the intake design.

pbm317

Ravskau.. i'm interested in your exhaust system.. care to tell a little more about it? I think my friend has a magnaflow on his Mustang.. and it sounds great.. very deep, throaty sound. Is yours similar?

Ludatic

yea it's probably the resonator.. on the prelude the resonator actually comes before the intake. I removed it and it basically sounds like i have an aftermarket intake, if i'm at WOT that is. At certain rpms it'll sound stock, like from 1-3k, but around 3kand up it gets pretty loud.. it's weird how all cars have resonators in difference spots, some come before the intake (which are easily removable), and some before the exhaust (which might be built in and require cutting)

MeTh222

I have the magnaflow single muffler (not sure of the model #). Just curious how much you paid for yours? I had mine done for $200 installed. It sounds really good and its not too loud. I heard that the dual magnaflow exhausts were dynoed by someone and gained 6 hp to the wheels! Common sense is telling me that the single I have will probably gain more.