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Discussion Starter · #1 ·
I admit the quiteness was killing me so I decided to do something about it. :blob: This morning I had a flowmaster 50 series delta flow street mufffler installed. The part number is 942553. It has the 2.5" inlet and outlets. Total cost $177.25. Total time 30 to 40 min. Its a perfect fit. Cut off the old (big one) one and this baby slips right in. Left the two existing back mufflers in place. Man, the old one weighed a ton, must of had a lot of something in there.
Sound is a nice improvement. Inside the car at idle, you can't hear it at all. Outside at idle, it has a nice purrr. On the freeway at 60 or whatever, its not noticeable. However, once the revs get up around 3000, you can start to hear it.
I almost would like it a tich louder, but I've only had it on for an hour. I do think the two rear mufflers cut down the sound. I would love for some of our "experts" to find out exactly what there function is. Do they cut down the sound much, or are they just there ito hold up the dual exhausts? How loud would it be without them? I've got a feeling they could be replaced two, but I think that's several months or more away.
I am curious if I will get any difference in gas milage. Time will tell.
With out doing some timed runs, I can't really tell if horsepower has improved. Of course the added varoooom, makes it feel faster.
Anyway, all things considered - I'm happy for now. :thumb:
 

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Re: Installed a FLOWMASTER 50 series Muffler

That could be interesting. Sounds like it didn't at all go overboard with the sound and ruin the persona of the vehicle, so that's a good thing--just a nice extra little growl.

The two rear "mufflers" are known as resonators, with the key function of simply cutting down the noise that gets past the muffler that much more--while really not impeding flow much, if at all. It's the typical way a lot of cars are set up OEM, and works well from a noise standpoint, unless you're looking for more. Lope them off, and you'll definitely see an increase in the volume, but it shouldn't be objectionable--it's a common thing with a lot of cars, when people want to "de-muffle" the sound more but not really do any more significant exhaust changes. Could be a LOT different than stock now with the Flowmaster thrown in now in place of the stock muffler AND resonators, but you'd have to be the guinea pig of sort since I doubt many Acadia owners have yet even looked at their exhaust.
 

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Discussion Starter · #3 ·
Re: Installed a FLOWMASTER 50 series Muffler

Great information on the resonators ! Thank you.
Since they don't cut down on the flow that much. I think I will live with them for a while.
It might have been interesting to have gone with the 70 series muffler (which is quiter) and then eliminated the resonators.
But I decided to play it safe. Maybe somebody else will give that a try.
 

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Re: Installed a FLOWMASTER 50 series Muffler

I'm tempted to do change out mine, but the wife would have a heart attack. We just traded in my custom Galant that was lowered, plus 2 size rims, and a custom cat-back. I was even getting tired of the loudness and bumpiness. But its in my blood now and the need to modify and be different is too great to overcome.

One question I have since I haven't looked to long and hard at the underneath...is the area around the main(big) muffler capable of allowing different sizes/shapes?

To bad though that this will more than likely void the warranty. Although some dealers are cooler about this than others.
 

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Discussion Starter · #5 ·
Re: Installed a FLOWMASTER 50 series Muffler

I would have to carefully read the warranty. It would amaze me if it did.
There is not a lot of play room around the big muffler, but that's partially because it soooo big. 21" by about 11" wide.

As I said, the 50 series easily fit. In fact it was slightly smaller then the origional. I had a 70 series on my aerostar and it was louder then this (it should be quieter), so I am pretty sure the resonators do cut down on the sound.

I looked at a Magnaflow muffler. It was bigger and would fit, but with the one they had in stock, they would of had to slightly bent one pipe. The Magnaflow would have been quieter.

I think it would be interesting to try the Magnaflow and get rid of the resonators. Of course if I had tried that my wife wouldn't of had a heart attack, she would just probably try to kill me (anything to drive the car more) ;D
 

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Re: Installed a FLOWMASTER 50 series Muffler

caddycruiser said:
That could be interesting. Sounds like it didn't at all go overboard with the sound and ruin the persona of the vehicle, so that's a good thing--just a nice extra little growl.

The two rear "mufflers" are known as resonators, with the key function of simply cutting down the noise that gets past the muffler that much more--while really not impeding flow much, if at all. It's the typical way a lot of cars are set up OEM, and works well from a noise standpoint, unless you're looking for more. Lope them off, and you'll definitely see an increase in the volume, but it shouldn't be objectionable--it's a common thing with a lot of cars, when people want to "de-muffle" the sound more but not really do any more significant exhaust changes. Could be a LOT different than stock now with the Flowmaster thrown in now in place of the stock muffler AND resonators, but you'd have to be the guinea pig of sort since I doubt many Acadia owners have yet even looked at their exhaust.
Perfect response. I took the cans off my Magnum RT. It added extra growl with little extra interior noise. It was a great compromise with the wife. I probably won't do it with this vehicle, because I don't consider it sporty enough for the growl. I happy your enjoying your flowmasters. Good job.
 

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Re: Installed a FLOWMASTER 50 series Muffler

sandman said:
With out doing some timed runs, I can't really tell if horsepower has improved. Of course the added varoooom, makes it feel faster.
Anyway, all things considered - I'm happy for now. :thumb:
You should have put the Acadia on a Dyno machine before & after the new muffler!

Someone should do this. I'm curious...
 

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Discussion Starter · #8 ·
Re: Installed a FLOWMASTER 50 series Muffler

I agree completely. :cheers:
Of course if I could have done that, I also would have been doing it with and without the resonators.
Actually I had planned to take it somewhere and do a few 0 to 60 timed runs, and then do it again after the installation. I had just stopped by the muffler shop here in San Pedro to get their opinion, and the switch was so easy, that I went for it on the spot.
 

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Discussion Starter · #9 ·
Re: Installed a FLOWMASTER 50 series Muffler

Finally took a drive today that I have done many times in the past. Usually I get 17-18 mpg (few stop lights, 45mph for about 13 miles), and I wound up with 20 mpg. Frankly, I think I got lucky as thats a pretty big jump. It will probably be another week till I can do a freeway shot. That will be interesting as I can usually get 24 mpg at 70.
The muffler itself is still fairly quiet. Its noticable when you get on it and accelerate. Its got a nice purrr at idle (only noticeable from the outside). So far I'm happy in that its definately not anywhere near loud. Still thinking about playing with those resonators.
I would love to know from some of our tech guys, if they have ever seen any tests on how many decibles they lower the output from the primary muffler.
 

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Re: Installed a FLOWMASTER 50 series Muffler

sandman said:
Still thinking about playing with those resonators.
I would love to know from some of our tech guys, if they have ever seen any tests on how many decibles they lower the output from the primary muffler.
It's really hard to judge, as it all depends on the engine and also the specific nature of the exhaust components. Sometimes they seem to make a considerable difference, but other times not so much, and just muffling a little extra rumble.

For your case, given how the results so far were pretty pleasant, I'd be tempted to just leave it alone. You could just whack them off cleanly (so things can be put back) and try it, but it's 50/50 whether you'll like the change or not, and you just won't know until you do.
 

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Re: Installed a FLOWMASTER 50 series Muffler

sandman said:
Finally took a drive today that I have done many times in the past. Usually I get 17-18 mpg (few stop lights, 45mph for about 13 miles), and I wound up with 20 mpg. Frankly, I think I got lucky as thats a pretty big jump. It will probably be another week till I can do a freeway shot. That will be interesting as I can usually get 24 mpg at 70.
The muffler itself is still fairly quiet. Its noticable when you get on it and accelerate. Its got a nice purrr at idle (only noticeable from the outside). So far I'm happy in that its definately not anywhere near loud. Still thinking about playing with those resonators.
I would love to know from some of our tech guys, if they have ever seen any tests on how many decibles they lower the output from the primary muffler.
Sandman, it's because it's lighter now.

You did say "Man, the old one weighed a ton, must of had a lot of something in there." :D
 

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Re: Installed a FLOWMASTER 50 series Muffler

Sandman

Ever get any photos of the muffler?

How has the change affected / added to the fuel mileage after longer term?

Just wondering. Had a dream of 2 shiney rear mufflers last night. ???
Thanks.
 

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Discussion Starter · #13 ·
Re: Installed a FLOWMASTER 50 series Muffler

Taking a 180 mile cruise today and should get some good mpg figures.
Picture won't show much as I replaced the master muffler, not the two small ones. I'm thinking of tinkering with those cause the sound is still very mellow. Trouble is they are really short and you might need some major pipe bending (on the back end) to get another one in there. I would love to get a polished chrome set by magnaflow or someone on there.
What I need to figure out is how much they muffle the sound from the primary muffler. I don't think I could simply eliminate them and go straight through to chrome tips, because I went with the 50 series. Makes me wonder if I could have gone with the 70 and then straight through.
Let me know if you start playing around. Find a place that lets you hear what different setups sound like. Replacing the big one is very easy. You can simply clamp different ones on (after cutting of the old one) and hear what they sound like, before making it permanent.
 

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Discussion Starter · #14 ·
Re: Installed a FLOWMASTER 50 series Muffler

Finished trip, it appears that I got slightly better milage. Usually on this trip I get 24 to 24.5. This time I was 24.8 to 25.2 while averaging 70 to 80. At 75 I was right around 24.9 - which, if I remember correctly, is better than I have done in the past. This was on a 90 mile trip.
This is a fairly slight difference which makes me think those resonators have a little more restriction than I thought. I would love to get a technical description on them.
I have not done enough consistant around town driving to notice a difference. Sometimes I think it is higher, sometimes not.
 

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Re: Installed a FLOWMASTER 50 series Muffler

sandman said:
Finished trip, it appears that I got slightly better milage. Usually on this trip I get 24 to 24.5. This time I was 24.8 to 25.2 while averaging 70 to 80. At 75 I was right around 24.9 - which, if I remember correctly, is better than I have done in the past. This was on a 90 mile trip.
This is a fairly slight difference which makes me think those resonators have a little more restriction than I thought. I would love to get a technical description on them.
I have not done enough consistant around town driving to notice a difference. Sometimes I think it is higher, sometimes not.
Doesn't matter in my opinion. I would think the nice purring sound from the new muffler would be well worth it.
 

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Discussion Starter · #16 ·
Re: Installed a FLOWMASTER 50 series Muffler

I agree - go for it :clap:
I do think you will have to play around a bit with different options.

I think I may talk with my muffler guy and see how much of a hassle it will be to slap some polished ones on in place of the resonators. If I do, I will definately take pictures . :cheers:
 

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Discussion Starter · #17 ·
Re: Installed a FLOWMASTER 50 series Muffler


Actuall link to Magnaflow
http://www.magnaflow.com/02product/parts/14375.jpg

Ok, it will be a couple of weeks before I have the time. But this is what I am thinking. Did some measuring and I think this will work. Use the above muffler (in either 2.5 or 2.25 inlet) in place of the resonators. Since the resonators are about 13 inches wide, (I think ??? I hope) there is enough room for this. They don't make a center/center muffler in this 11 inch length. I am thinking of these tips cause they are the shortest.


The whole thing would be all polished stainless steel and should look really sharp. The Price would be about $530 not counting labor (or shipping?).
Since I have already replaced the big muffler. I would be done. For the rest of you, I would try these in place of the resonators, listen then decide what to do with the big guy.
Realize, I am not sure that any of this will fit. But I've measured and it looks possible. My next step will be to go down to my muffler place and see what they think.
 

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Re: Installed a FLOWMASTER 50 series Muffler

Boy it would be great to get a sound clip...Are you able to do anything?
 

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Discussion Starter · #19 ·
Re: Installed a FLOWMASTER 50 series Muffler

Going down to the muffler shop Wed or Thur. If they think it can be done, I imagine I will need to order the parts - so perhaps some time next week I might have something.
As far as sound goes - my iriver mp3 will record and I can drop that into my computer, but it looks like only text and picture types can be shown "Allowed file types: doc, gif, jpg, mpg, pdf, png, txt, zip Maximum attachment size allowed: 512 KB, per post: 4[/color]" - so I don't know if its possible to post sound.
Any ideas?
 

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Re: Installed a FLOWMASTER 50 series Muffler

sandman said:
Going down to the muffler shop Wed or Thur. If they think it can be done, I imagine I will need to order the parts - so perhaps some time next week I might have something.
As far as sound goes - my iriver mp3 will record and I can drop that into my computer, but it looks like only text and picture types can be shown "Allowed file types: doc, gif, jpg, mpg, pdf, png, txt, zip Maximum attachment size allowed: 512 KB, per post: 4[/color]" - so I don't know if its possible to post sound.
Any ideas?
Yes, place the sound clip inside of a zip file, then attach the zip file to the forum.
 
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