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Discussion Starter · #1 ·
I just got a dynomax muffler and am looking to install it in place of my resonator, as I was told its an exact fit. Can the resonator be removed without having to remove any other exhaust components, or will I have to pull all the pipe and re-install it as one piece?

considering money Vs effort, should I just take it to an exhuast shop?
 

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I'm pretty sure you have to put the new muffler in place of the old muffler which is under the car in the middle. The resonator is the box at the end of the car where the exhaust tip comes out.
 

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The muffler is in the rear, resonator up in the middle.

If you put a muffler in the middle, remove the rear muffler as well.
 

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Wait, now I'm confused. I thought the muffler was in the middle, cuz let's say you get the yodude dual exhaust, it comes with a muffler, which looks exactly like the thing under the car in the middle. Our car has two mufflers?
 

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The resonator is up front and the muffler is in the rear. I just corrected the exhaust set-up the prior owner of my cat did (he actually paid a shop to do it and I'm surprised they didn't talk him out of it). He had the muffler removed and had a 3 1/2" stainless resonator tip installed. Needless to say, this set-up had so little back pressure that the motor had absolutely no low end (torque)....not to mention it was very loud....hahaha!

I had a local shop remove the resonator up front and replace it with a performance muffler, which splits into 2 1/4 duals back to the tips. It runs so much better now....:) The owner of the shop told me running the muffler up front was better since it reduces the amount of condensation in the muffler which will minimize rust holes in the long run.

Anyway, just my 2 cents....:)
 

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Trying to help clarify: on a stock exhaust, your flow should be

exhaust manifold -> catalytic convertor -> resonator -> muffler (near rear bumper, it's a big ugly thing) -> exhaust tip

My recommendation after having two Cougars with two different systems: leave the stock resonator in tact (removing the resonator gave my Cat a note too raspy for my taste) and use dual mufflers. I have included a pic below that shows a dual muffler setup without the resonator.

You may also want to look at this recent thread and this link provided by Mortis.

Finally, this web page has some interesting info on exhausts.

Hope some of this helps you out.:)
 
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Discussion Starter · #8 ·
This is all great advice! So how difficult is the task of removing the resonator and putting this Dynomax in its place (exact fit)? will I be able to re-use exising hardware (clamps etc...)? my exhuast is not very rusted, and I have ramps.

I searched the How-To's, but couldn't find a "How to remove Resonator" type of string. I would love to do this myself because I am getting price quotes all from $45 - $200, every shop needs to look at the car first, but I like 'have a job' and can't just be going and getting car mods done all day :)
 

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I wish I could help more, but:
-I didn't perform my exhaust upgrade
-and I didn't do the single muffler sans resonator method
 

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I took mine to a shop (I wanted the exhaust system connections welded), but I supplied the muffler and the tips. I just needed them to to weld, bend pipes and make hanger brackets.

If you're just going to do a direct swap with the muffler for the resonator, you'll actually have two mufflers, the one you swap....and the original one in the rear. That's a lot of back pressure in your exhaust system.
 
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Discussion Starter · #11 ·
I have a Dynomax SuperTurbo muffler on my cat. I paid a shop to remove the resonator and stock muffler and replace with just the dynomax. I plan to go back and replace all of the piping with the larger size (I think it's 3.5" the whole way...not sure though). I have very little low end torque but the car sounds nice, very very deep and not loud at all. Would adding the resonator back in the middle of the car increase the low end torque without changing the sound?
 
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Discussion Starter · #12 ·
crap..............i removed the wrong one
so im just running with a resonator and no muffler!!!!!!
guess it time to shop for a muffler.:flushed:
 

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Adding back a resonator would help, but not much. You need a reasonable amount of back pressure for low end torque. That's the compromise we all make when setting up an engine. Too bad we don't drive WOT all the time....then it wouldn't matter....:)

My Cat used to be like that......(Just a resonator and a resonator tip)...it was set up like that when I bought it....and it had absolutely no back pressure and it was LOUD. With no low end, I would have to pretty much stand on the throttle from a stop just to keep up with traffic...:banghead:

If I were you, I'd add the resonator, but not go to 3.5" plumbing....it would just make it (lack of low end) worse. But then again, it's your choice.....I'm sure it sounds Real Nice.....:biggrin:
 
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Discussion Starter · #14 ·
I now have the same setup as Tut. Any rasp dissapears within about 3 minutes.

Regarding low end torque-I can't tell if I lost any, but i wish I knew that before I made the mod.
so just freeing up HP doesn't always make you faster I guess.
 

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NO NO NO!!!!!

There is no corrolation to backpressure and torque! This has been discussed many many times on the forums. A quick synopsis is in order: Back in the days of carberation, backpressure did add torque, because of a condition called double loading... The backpressure would cause air that had already recieve Gasoline to return to the carb, and be loaded again with more gas. This caused twice as much fuel to enter the combustion chamber... Therefore, a boost in power. These days, there is fuel injection, which eliminates this effect. Do a search, I know there is a huge article by BMW about this somewhere, It is very informative! Hope this sets everyone straight.

Darcy
 

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He is telling the truth, backpressure doesn't add torque!
 
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Discussion Starter · #17 ·
Backpressure doesn't directly affect torque, but the scavenging effect that it has does determine the amount of airflow and pulse. that kind of stuff. pretty technical....
 

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Here's how I understand it, please correct me if I'm wrong.

It's the exhaust velocity that affects torque. A smaller diameter pipe means the gases exit at a higher speed. For low end torque, this is good because it creates a kind of vacuum effect, pulling the exhaust out. However, during high rpm driving, a larger diameter pipe is preferable, because of the large amount of exhaust gas that has to escape.
 

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That's how I understand it. Exhaust back pressure doesn't increase or decrease the amount of torque a given engine can produce. But it does have an effect on where that torque is developed within the usable powerband (RPM's).

With less back pressure, the torque curve is higher relative to RPM's. This is extremely noticeable with 2-stroke engines (hence the expansion chambers for race engines).

To illustrate the point, from a stop, accelerate to 2000 RPM's. Take notice of the distance and your speed when you hit 2000 RPM's. Now disconnect your exhaust after the cat (basically uncap it), then do the same thing. You'll notice a big difference in both distance and speed when you hit 2000 RPM's.

Although you haven't really lost any of the overall torque the engine is capable of producing....it's just been moved higher within the powerband. Thus that's why it's called a loss of low end. Torque is not being produced in the lower RPM range.

This may not seem like such a big deal in and of itself, but consider that cars are designed to operate within a range of engine speeds (RPM's). These are drivability issues rather than one of engine power.
 
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Discussion Starter · #20 ·
I've always wondered what the difference is if you have Resonator only versus a muffler only. I know that muffler I have has a switch back inside which decreases the amount sound while a resonator is pretty much straight through. Is there a difference in hp/torque/speed etc. depending on which device is actually connected? I'd love to swap out my SuperTurbo for a different muffler that makes a little more noise.
 
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