Name : Rick Age : 46 Location : CT Joined : 2009-03-03Post Count : 1429 Merit : 37
Subject: Re: FAQ: The Exhaust Thread Wed Dec 16, 2009 8:03 pm
I agree with Codith. Holden 3800s sound almost exotic while everything over here sounds like crap (Camaros as well even though they are L mounted setups). It's odd that the Camaro would sound bad when it's a longitudinal setup... you'd think the manis would be equal length allowing for better exhaust pulsewidths. Oh well. I'd love a RWD 3800 setup with that exhaust note and the blower whine up front. Oh boy! :O
Karma Aficionado
Name : Andrew Age : 40 Location : Ontario, Canada Joined : 2008-01-14Post Count : 1949 Merit : 123
Subject: Re: FAQ: The Exhaust Thread Thu Dec 17, 2009 8:57 am
I'm still wondering how this will turn out sound-wise:
I've been toying with trying something like it this winter since the car is stored for winter work and I wanted to try my hand at making some series one headers.
_________________
turtleman Expert
Name : Codith Age : 37 Location : Villa Park, IL Joined : 2007-02-08Post Count : 3671 Merit : 140
Subject: Re: FAQ: The Exhaust Thread Thu Dec 17, 2009 2:00 pm
It sounds like that ones almost there
Eldo Expert
Name : Mark Age : 59 Location : West Salem, Oregon... FINALLY Joined : 2009-04-09Post Count : 3174 Merit : 104
Subject: Re: FAQ: The Exhaust Thread Thu Dec 17, 2009 4:20 pm
Better, but still more snarl than burble...
DEMonte1997 Aficionado
Name : Rick Age : 46 Location : CT Joined : 2009-03-03Post Count : 1429 Merit : 37
Subject: How many guys are running GTP mufflers with stock exhaust? Sat Dec 26, 2009 3:15 pm
Just curious after Midas told me they wouldn't fit.
Rickw Guru
Name : Rick Location : Lancaster, MA Joined : 2008-09-13Post Count : 6282 Merit : 119
Subject: Re: FAQ: The Exhaust Thread Sat Dec 26, 2009 3:31 pm
Midas isn't into the "Custom" exhaust game. If they don't bolt right up perfectly they will say they don't fit. These (GTP) mufflers may indeed fit with a little work. Maybe some adapters and welding, etc. Do you know what the dimensions of the GTP mufflers are.?? That would be the first thing needed to know, then determine if there is enough room for them under the Riv. The inlet and outlet pipe diameters would be nice to know also. So, if you can find out the length and width of the muffler body, then the inlet and outlet diameter's we can see if they will fit with a little finesse. I'd be interested in hearing them also.
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8685 Merit : 181
Subject: Re: FAQ: The Exhaust Thread Sat Dec 26, 2009 6:50 pm
I decided to "silence" my exhaust, a friend will help me pull this off on New Years' Eve. "Film at eleven."
Albertj
Rickw Guru
Name : Rick Location : Lancaster, MA Joined : 2008-09-13Post Count : 6282 Merit : 119
Subject: Re: FAQ: The Exhaust Thread Sat Dec 26, 2009 7:07 pm
albertj wrote:
I decided to "silence" my exhaust, a friend will help me pull this off on New Years' Eve. "Film at eleven."
Albertj
O.K. Albert I'll bite. What have you got planned, please share.!!!!
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8685 Merit : 181
Subject: Re: FAQ: The Exhaust Thread Sat Dec 26, 2009 10:32 pm
Most likely "sharing" will have to wait until after the deed's done. In the meantime here is some not-necessarily-related food for thought:
Name : Rick Age : 46 Location : CT Joined : 2009-03-03Post Count : 1429 Merit : 37
Subject: Re: FAQ: The Exhaust Thread Sun Dec 27, 2009 6:47 pm
Rickw wrote:
Midas isn't into the "Custom" exhaust game. If they don't bolt right up perfectly they will say they don't fit. These (GTP) mufflers may indeed fit with a little work. Maybe some adapters and welding, etc. Do you know what the dimensions of the GTP mufflers are.?? That would be the first thing needed to know, then determine if there is enough room for them under the Riv. The inlet and outlet pipe diameters would be nice to know also. So, if you can find out the length and width of the muffler body, then the inlet and outlet diameter's we can see if they will fit with a little finesse. I'd be interested in hearing them also.
Measured them today. See if this sounds kosher:
H 8" W 11.5" L 14"
Height is obviously higher than the stock Riv muffs but I don't think it's ridiculous. Offset inlet, center outlet. 2" in and 2.5" out.
Rickw Guru
Name : Rick Location : Lancaster, MA Joined : 2008-09-13Post Count : 6282 Merit : 119
Subject: Re: FAQ: The Exhaust Thread Sun Dec 27, 2009 7:20 pm
Do you currently have a set of these mufflers or are you measuring someone else's.? Just curious. I will need to dig out my files on Mufflers and see what notes I took a while back on what will fit. I had it up on a lift and did some measuring with the thought of putting some aftermarket mufflers on it. But after hearing what other people have gone through with noise and drone issues I put it on the back burner.
Rickw Guru
Name : Rick Location : Lancaster, MA Joined : 2008-09-13Post Count : 6282 Merit : 119
Subject: Re: FAQ: The Exhaust Thread Sun Dec 27, 2009 8:24 pm
I found some of my notes on Mufflers. Stock muffler is 15" long by 11" wide (didn't measure height or thickness). Maximum available space, will accommodate a muffler comfortably, no larger than 20" long by 12" wide. Now I just need to measure our inlet diameter, unless someone on here already knows this info.!!! So how much are the GTP muffler's and from what year did you get measurements from.???
So far it looks like the GTP's will fit. The exhaust pipe diameter going into the muffler doesn't have to match the 2" inlet of the muffler. Any size is weldable with adapter's, etc. So I think these will be a good fit. Does the GTP muffler have a single outlet tube that will allow the welding on of some nice tips.?? Did you choose the GTP mufflers because of the sound they make.? I guess I need to find a stock GTP and listen to them. I have a pair of Tips that I bought a long time ago and have been waiting to install in case I do change mufflers.
DEMonte1997 Aficionado
Name : Rick Age : 46 Location : CT Joined : 2009-03-03Post Count : 1429 Merit : 37
Subject: Re: FAQ: The Exhaust Thread Sun Dec 27, 2009 10:50 pm
I got the GTP mufflers for free from a local guy. He was really cool about it. Said they were rusting in his backyard along with the catback exhaust so I took a sawzall and cut them off. Got really nice GTX trapezoid tips with them but I don't think they will go on the Riv. I already cut them off and repolished them.
I just went with the GTP mufflers because they should give the car a little more sound but not a ridiculous amount (ie: not what the Regal has with headers and Ultraflo mufflers).
Do you knowk how tall the stock Riv mufflers are? The guy at Midas was convinced the GTP exhaust wouldn't fit because they were way too tall.
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8685 Merit : 181
Subject: Re: FAQ: The Exhaust Thread Mon Dec 28, 2009 12:19 am
Muffler inlets are 1 7/8" - they reduce from 2 1/4 or 2 1/2" at the Y after the exhaust pipe (the pipe with the funky bends after the resonator).
Albertj
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8685 Merit : 181
Subject: Re: FAQ: The Exhaust Thread Mon Dec 28, 2009 12:33 am
DEMonte1997 wrote:
I got the GTP mufflers for free from a local guy. He was really cool about it. Said they were rusting in his backyard along with the catback exhaust so I took a sawzall and cut them off. Got really nice GTX trapezoid tips with them but I don't think they will go on the Riv. I already cut them off and repolished them.
I just went with the GTP mufflers because they should give the car a little more sound but not a ridiculous amount (ie: not what the Regal has with headers and Ultraflo mufflers).
Do you knowk how tall the stock Riv mufflers are? The guy at Midas was convinced the GTP exhaust wouldn't fit because they were way too tall.
Depends on where you are going to mount the GTP mufflers. If you are putting them in the stock locations I doubt it matters all that much although they are 8" tall. You'd have to check clearances and tweek the pipes a little.
On the other hand - If you mount them approximately as they are mounted on the GTP they are a bit too close to the trunk floor pan - so although most people would ignore that little situation you really should stick some heat shields up over them, aluminum sheet on 1" phenolic or metal standoffs screwed through to the floor pan would be great. You would probably want to cut the stock exhaust *before* the Y and put a larger Y or a box in its place with pipes from it angled straight such that you could hang the GTP mufflers under the rear fender skirts, behind and just inboard of the rear wheels. They probably would *look* out of place - those big cans will be pretty visible - but if you look at a bunch of current cars you will notice that a lot of them are equipped with mufflers that are pretty far back like that, and I am told it improves performance somewhat to do so. It will be noisier because you will have shortented the exhaust path.
Albertj
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8685 Merit : 181
Subject: Re: FAQ: The Exhaust Thread Sat Jan 02, 2010 2:23 pm
albertj wrote:
I decided to "silence" my exhaust, a friend will help me pull this off on New Years' Eve. "Film at eleven."
Albertj
So here is the "film."
Installed a GM exhaust, the GM RPO for the '04 Park Avenue Ultra. p/n 25749911. One welded assembly with a cat, resonator, 2 mufflers, all pipes, in T409 stainless (exc the polished tips, I can not tell if they are chrome plated or T304 - probably plated 409's my guess. It is 12 feet long.
It fits pretty much right off the truck, just needed to modify the heat shield for the rear oxygen sensor wiring 'cause the bung is fore of the old OE location by a couple inches. If you get one of these you can put on a new bung and plug the old, or extend the wire cover (easily done with sheet metal and pop rivets). And you should extend the front heat shield over the cat (they moved it forward I suppose to make it light off better) with sheet metal; I epoxied the new extension to the OE heat shield. For $50 you might get the PAU heat shield and install it with the muffler, though.
The 25749911 hangs from the exact stock Riv locations (thanks Jason) and came with new rubber hangers. The rear muffler cans are somewhat bigger than the OE Riv cans but still fit the stock locations, and the tailpipes come out to chrome round anglecut and rolled tips just under the outer corners of the bottom of the rear bumper cover. Unlike the OE Riv tips, these stick out a little from under the lip of the bumper cover.
I kind of miss the custom exhaust's growl and rumble already - but not that much. It went to a great home on a buddy's '96 Riv, which is way better than just hanging it in the man-cave. However, on the shakedown drive I noticed the flat spot in acceleration I had with the OE mufflers did not come back (yay!). And it's running great. I suppose that due to age and use the old cat may have been partly blocked, but I really don't know - when I looked at it/thru it I could see thru to the other side okay - but in the "honeycomb" substrate it could be the case that it had blocked over time toward the outer edges of the oval cross-section, and I did not open the can to check if I could see through along the edges. It's not uncommon to have peripheral blockage in a cat over time, I am told, because the cats run hotter in the center than at the edges, and they may soot up over time in the cooler regions. In the center due to extreme heat the soot would always burn off unless you misfuel or some such and poison the catalyst.
So I am thinking that (a) the flat spot maybe was my imagination (b) replacing the plugs and ignition module (for maintenance) maybe actually did the trick - plugs had been in a bit more than 100K miles and were worn (c) the new exhaust is different; the muffler cans are bigger than the Riv's were (d) something else is going on.
And it is really, really quiet. I guess in part because of the sound deadening I did for the custom muffler and in part because this exhaust seems quieter than the OE Riv's due to those bigger muffler cans. Now the loudest sound in the car when rolling is the tires (my snows whine). After it's on a while I'll get the sound meter and measure dB at idle and cruise. The custom pipes registered 80-some dB at cruise before and I think 69dB at cruise after adding eDead and a mass loaded vinyl barrier in the trunk and under rear seat. My post earlier this thread says what the measurements were. As for new measurements We Shall See. I'll take the sound meter out on a cruise soon.
Albertj
Last edited by albertj on Sun Jan 03, 2010 7:49 pm; edited 3 times in total (Reason for editing : to fix omissions)
deekster_caddy Master
Name : Derek Age : 52 Location : Reading, MA Joined : 2007-01-31Post Count : 7717 Merit : 109
Subject: Re: FAQ: The Exhaust Thread Sat Jan 02, 2010 11:14 pm
Wow, very cool. How about a vid of the sound albert?
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8685 Merit : 181
Subject: Re: FAQ: The Exhaust Thread Sun Jan 03, 2010 7:36 pm
Rickw wrote:
albertj wrote:
However, on the shakedown drive I noticed the flat spot in acceleration I had with the OE mufflers did not come back (yay!), I guess in part because of the sound deadening I did for the custom muffler and in part because this exhaust seems quieter than the OE Riv's due to those bigger muffler cans. Albertj
How could a flat spot in acceleration be eliminated by sound deadening? I can understand the performance of the engine being affected by the exhaust system itself but not by sound deadening materials that were added to the chassis.
I assume that was a big typo on my part.
This week I am working on a business plan, and one thing I noticed that was happening today is that my palm and/or thumbs brush the touch pad on the keyboard (I have a *small* laptop) and sometimes ends up cutting text. I noticed it earlier today as I was writing. I usually spot it to fix it but sometimes not, and I have turned the trackpad off for the time being. I open up a RivPerformance window and will write a little of a post at a time during short breaks in working, and I suspect what you saw basically was a typo or I just did not complete the thought before I hit 'send.' .
As for your point - that's a great point and true of course. Flat spot is not affected by sound deadening. I think the problem in the post is that I wanted to mention that the loudest sound in the cabin at cruise now is the whine from the tires, I guess in part due to the sound deadening and in part due to whatever's in the bugger muffler cans.
So - I'll go back and fix the post...
With the old exhaust, I had a 'flat spot' in acceleration. Sound deadening had nothing to do with gettiing rid of it -- the new SS exhaust seemed to. Back to the point -- I was expecting the flat spot to come back with the new OE exhaust, and it did not. And it's running great.
I suppose that due to age and use the old cat may have been partly blocked, but I really don't know - when I looked at it/thru it I could see thru to the other side okay - but in the "honeycomb" substrate it could be the case that it had blocked over time toward the outer edges of the oval cross-section, and I did not open the can to check if I could see through along the edges. It's not uncommon to have peripheral blockage in a cat over time, I am told, because the cats run hotter in the center than at the edges, and they may soot up over time in the cooler regions. In the center due to extreme heat the soot would always burn off unless you misfuel or some such and poison the catalyst.
So I am thinking that (a) the flat spot maybe was my imagination (b) replacing the plugs and ignition module (for maintenance) maybe actually did the trick - plugs had been in a bit more than 100K miles and were worn (c) the new exhaust is different; the muffler cans are bigger than the Riv's were (d) something else is going on. The something else: to the OEs, Arvin (and the mufflers on the new exhaust are Arvins) has supplied this 'dual mode' technology since 2002 they say:
I do not know which GM mufflers use this technology. On the one hand they do not have the out-of-the-shell loop as pictured. On the other hand the cans seem bigger than the OE Riv ones, and one could easily get that loop inside a bigger can -- and I can't see how it would cost any more to make. On the third hand, GM is not known for spending 'extra' money, so the cans likely ahve conventional guts. It will be some months before I can find out. I'm not cutting a can open...
Anyway - for what it's worth the marks stamped on the mufflers are:
GM G7-5179-R ARVIN B AM 2818
and
GM G7-5179-L ARVIN C AM 0639
Resonator is
GM C6 5961 AW 1 183 9
Hope this helps
Albertj
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8685 Merit : 181
Subject: Re: FAQ: The Exhaust Thread Sun Jan 03, 2010 7:38 pm
deekster_caddy wrote:
Wow, very cool. How about a vid of the sound albert?
Not sure it's worth it. They are quieter than the 'burbling' OE ones.
If they really flow as well as they seem to, would make a great 'sleeper' exhaust.
Albertj
crlombardi69 Enthusiast
Name : Chris L Age : 55 Location : Metro/Detroit area Joined : 2009-12-31Post Count : 207 Merit : 5
Subject: Re: FAQ: The Exhaust Thread Wed Jan 06, 2010 6:27 pm
Has anyone out there ever removed the resonator and left the factory mufflers or remove the mufflers and replace them with straight pipes w/nice tips??Wondering how this would sound without having to try it myself before I do my full custom exhaust because no exhaust companies see the value in offering us some systems.
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8685 Merit : 181
Subject: Re: FAQ: The Exhaust Thread Wed Jan 06, 2010 10:22 pm
my guess is the resonator is a 'helmholtz' type silencer (after all it is made by Arvin on the OE system) intended to push the sound of the exhaust below the audible range (basically converting it to heat via resonance)
reason for this guess is I did some more sound measurements.
First a reminder:
A-weighted measurements means, roughly speaking, measuring the sound pressure levels primarily (in the middle to high octaves) from 500 to 8000 hz. People can hear from around 20 Hz to 20,000 Hz but a s a practical matter due to physiology and environmental damage (loud music, occupational noise, or what have you) most people don't hear all that well outside of the 500 to 8000 hz range. So you could say that A-weighting discounts the lower and higher frequencies that the average person cannot hear well. One use of this weighting is to reckon the audio performance of telecommunications (2way radios, phones, and such) equipment.
C-weighting measures the bottom (~16 Hz) and top (~16,000) octaves discounted 10dB and does not discount sound pressure levels in the octaves between. C-weighting gives you a better reckoning of sound levels in musical performance (of stereos, music halls, and the like).
With the PAU exhaust I got;
PARKED, ENGINE OFF
55-60 dB-A (decibels, A-weighted) 55-70 dB-C (decibels, C-weighted) I figured a baseline would not hurt. The question kind of is, how much and how intense is the background noise verusus the noise generated by engine/drivetrain/tires/wind rush. I did not measure octave by octave to find out where (what frequency) that noise was. I was parked in a rural area off a 2-lane secondary road. 55 dB would be the plain old background (there is an interstate about a mile away, that and wind thru nearby trees account for the 55 dB), and 60 or 70 dB is where the meter peaked due to passing cars nearby)
START/COLD IDLE
63 dBA 74 dBC The point is that the engine and drivetrain, in my Riv, make noise at idle that are, in the cabin, louder than ambient where I live. I was in a rural area. It would not surprise me to find that in some urban environments or near a busy street/highway, one could not hear the Riv idling because ambient noise drowns out the idling motor's sound.
HIGHWAY CRUISING
63-66 dBA 78-83 dBC
What I really measured here was cruising at 65 on asphalt, on concrete and accelerating to 70 taking A and C-weighted measurements, then just putting the ranges down. The way this was done is there is a patch of highway near me that crosses several bridges, were all built and opened about the same time (a city bypass interstate link). So in the space of a couple miles I could see the measurements, slow back down, push the weighting button to change from A to C on the meter, then measure again - exit at a flyover and run back the other direction on similar surfaces to verify.
What I noticed was that the C-weighted sound pressure level (SPL) was substantially higher than the A-weighted - leading me to believe that the Riv is engineered to resonate such that a lot of what you would hear as noise gets pushed out of the typical audible range.
Why?
The hint to me here is: the Riv has a HUGE resonator. I suspect that they are using the huge resonator to lower the frequency of the engine noise, then due to the rigidity of the cabin, the cabin does not resonate such that the noise comes back as a harmonic. Think of the resonator as a really long, relatively fat organ pipe. Unmuffled, the 3800 rasps like a cicada on steroids. That resonator shifts the rasp and in addition, the funky-shaped Y-pipe should reflect some sound back on itself to cancel more of it out.
Then you have those huge mufflers. Sized as they are even with those crazy straws they are getting exhaust from they only need to pass somewhat under 200 CFM each - my guess is they should handle more, ~250 CFM, each. They are not really taxed at all and should not present any significant restriction to the exhaust. As far as their construction goes, thinking about it, they are probably like the Maremont Cherry Bomb "Turbo" mufflers - more or less a conventional set-up. I seriously doubt there is any funky plumbing inside although it'd be nice to see becasue they were not light weight.
As far as what Chris Lombard is saying, I suspect the move to get a more muscluar sound from the Riv would be to LEAVE the resonator in place and put old-school Cherry Bomb or the relatively new design Hooker Maximum Flow mufflers in their place. If you put in Cherry Bombs--I suggest that you *not* weld them in, as you know they don't last very long. The resonator as it is gets rid of a sound (that is, gets rid of a tone not the volume per se) you probably don't want (no matter how loud you want the exhaust to be), and based on personal experience I'd leave it the heck alone.
I have to run
Albertj
PS whatever you do leave that @#*$&@(#* Resonator in there. Or put in a bigger one.
Albertj
Last edited by albertj on Wed Jan 06, 2010 10:51 pm; edited 1 time in total
Eldo Expert
Name : Mark Age : 59 Location : West Salem, Oregon... FINALLY Joined : 2009-04-09Post Count : 3174 Merit : 104
Subject: Re: FAQ: The Exhaust Thread Wed Jan 06, 2010 10:36 pm
crlombardi69 wrote:
Has anyone out there ever removed the resonator and left the factory mufflers or remove the mufflers and replace them with straight pipes w/nice tips??Wondering how this would sound without having to try it myself before I do my full custom exhaust because no exhaust companies see the value in offering us some systems.
I've been tempted to do exactly what you're talking about ever since I bought the car. The main reason I haven't, besides labor costs, is that it has been pretty well proven that you can never get a 90-degree V6 to sound that good out the back...
And Albert, quite a deep dissertation!
crlombardi69 Enthusiast
Name : Chris L Age : 55 Location : Metro/Detroit area Joined : 2009-12-31Post Count : 207 Merit : 5
Subject: Re: FAQ: The Exhaust Thread Wed Jan 06, 2010 11:05 pm
I know about the 90 deg. Engine sound but I kinda like it but on the other hand I don't want my luxury coupe to sound like a ricer piece of sh__!!
Eldo Expert
Name : Mark Age : 59 Location : West Salem, Oregon... FINALLY Joined : 2009-04-09Post Count : 3174 Merit : 104
Subject: Re: FAQ: The Exhaust Thread Wed Jan 06, 2010 11:19 pm
crlombardi69 wrote:
I know about the 90 deg. Engine sound but I kinda like it but on the other hand I don't want my luxury coupe to sound like a ricer piece of sh__!!
Exactly... Here's a green + for you!
albertj Master
Name : Location : Finger Lakes of New York State Joined : 2007-05-31Post Count : 8685 Merit : 181
Subject: Re: FAQ: The Exhaust Thread Wed Jan 06, 2010 11:25 pm
crlombardi69 wrote:
I know about the 90 deg. Engine sound but I kinda like it but on the other hand I don't want my luxury coupe to sound like a ricer piece of sh__!!
Short answer:
If you leave the resonator in place you can get a nice muscular sound from a pair of 'performance' mufflers - flowmasters, vortex, what have you. I recommended Hooker Maximum Flow because of construction and flow data - they are stainless guts wrapped in aluminized steel shell, welded construction; they flow darn well and due to the case steel sound pretty mellow - I think if you do a web search you'll find sound clips *and* you'll find the flow data.