resonator/expansion chamber question

mbtoloczko · #1 11-08-2002, 03:26 PM

Hey, has anyone every hacked apart the resonator on an SVX exhaust to see what the interior design is? I'd like to know what it looks like so I have a muffler shop build me a custom exhaust, I can tell them what I need for a resonator.

Cheers,

Earthworm · #2 11-09-2002, 03:50 PM

Are you planning on keeping the resonator? Is/was it rattling?

If you don't need it then donate it.

mbtoloczko · #3 11-09-2002, 07:21 PM

I'm thinking of having a muffler shop build a custom exhaust system, and I would like to know how to duplicate and perhaps improve the design of the stock resonator.

DavieGravy · #4 11-10-2002, 12:34 AM

I know the pipe goes straight through. As for what's in that extra space, I haven't a clue.

#5 11-10-2002, 12:53 AM

smurfs. It has to be smurfs.

- Ca$H

alia176 · #6 11-10-2002, 06:17 PM

Sorry guys, but a dumb question here! Is your resonator falling apart or too quiet or too noisy?

Inquiring minds and all that...

DavieGravy · #7 11-10-2002, 06:33 PM

After so many miles, the resonators start to rattle very loudly. It can become quite annoying, but fortunately, it's a cheap fix if you get a custome welding job.

alia176 · #8 11-11-2002, 02:40 PM

Ok, I can handle the welding job. I assume the internals are separating and that's what you're talking about welding here? If not, then external stuff like shields, flanges are a wear item?

I'm boning up on this topic in preparation of the inspection of my "loud exhaust" syndrome! Thanks for humoring me.

oab_au · #9 11-11-2002, 04:00 PM

Quote:

Originally posted by mbtoloczko
I'm thinking of having a muffler shop build a custom exhaust system, and I would like to know how to duplicate and perhaps improve the design of the stock resonator.

Well,,,,The resonators function, is to terminate the tuned length of the engine pipes, to the length that will return the negative wave, to the cylinder at the designed rpm.

It is designed to provide a dummy end to the pipe so that the plug of high pressure exhaust gas can expand into it, to loose pressure as quickly as possible.

It is positioned at a point along the pipe, so that the sound pressure wave will reflect back to the cylinder to drop the pressure, as the piston is rising on the exhaust stroke, at the designed rpm, about 3500/4000 rpm. If it is moved back along the pipe it will resonate at a lower rpm. If it is moved up the pipe it will chime in at a higher rpm.

The construction has to be robust to withstand the battering that the sound waves give it , no flat sections. It can have a larger volume to help with the expansion of the gas plug, especially if the engine has forced induction or No2. A Turbo's exhaust is different and should only use a large pipe to drop pressure, no resonator.

It's position along the pipe is important, and should be retained at that distance. If the front end of the system has been altered, the cats removed, then it is a new ball game, as all the components in the line affect the resonate length.

The quite exhaust sound that the SVX has, does not mean restriction, it just shows how much of the energy has been used to produce torque, little is wasted out the back.

Harvey.

Hope this will help you.

alia176 · #10 11-12-2002, 07:20 AM

Thanks for the explanation.

SVX10 · #11 11-12-2002, 08:02 AM

You seem to know a good amount about the whole scavenging/resonance thing. Maybe you can give me a suggestion. I'm thinking about cutting the stock resonator out of my leftover stock piping, and installing it in my KC system (trying to get rid of some buzzing). I also have my front 2 cats removed. Now, since the piping is bigger on the KC system, and the area where the cats were is now straight through, do you (or anybody else who knows anything about this) think that 1) I should install a resonator 2) Is the stock one suitable 3) If installed, should it go in stock location, upstream (towards engine), or downstream (I'm looking to regain low end torque). I just wanna know what you think, and why, if that's not too much trouble. If so, I'll always take links so that I can read up on this stuff. Thanks.

Mat

oab_au · #12 11-12-2002, 03:32 PM

Quote:

Originally posted by SVX10
You seem to know a good amount about the whole scavenging/resonance thing. Maybe you can give me a suggestion. I'm thinking about cutting the stock resonator out of my leftover stock piping, and installing it in my KC system (trying to get rid of some buzzing). I also have my front 2 cats removed. Now, since the piping is bigger on the KC system, and the area where the cats were is now straight through, do you (or anybody else who knows anything about this) think that 1) I should install a resonator 2) Is the stock one suitable 3) If installed, should it go in stock location, upstream (towards engine), or downstream (I'm looking to regain low end torque). I just wanna know what you think, and why, if that's not too much trouble. If so, I'll always take links so that I can read up on this stuff. Thanks.

Mat

I think I have answered you on the "backpressure" thread.

If you want to read up on this subject, I would recommend, " The Scientific Design of Exhaust and Intake Systems". by Philip Smith. I must add it's not for wimps. It is based on work done be a Scot Engineer, John Morrison, who did all the experiments. An old book 1962, but nothing has changed since, its all based on this theory.

Harvey.