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 FAQ: Mufflers?

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turtleman
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptySun Oct 31, 2010 4:06 pm

Rickw wrote:
How did all that work out.?
added fuel setup to my showroom
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robotennis61
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PostSubject: Inside the muff   FAQ: Mufflers? - Page 8 EmptyMon May 30, 2011 11:11 pm

If anyone was curious to know how restrictive our OEM muffs were,here ya go....

FAQ: Mufflers? - Page 8 HPIM1163

FAQ: Mufflers? - Page 8 HPIM1162

FAQ: Mufflers? - Page 8 HPIM1161

I'll Tell you,there is no other opening to the exhaust tip,than through these tiny perforations.No slot for the bulk of the exhaust to get through.Nothing.
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AA
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyMon May 30, 2011 11:31 pm

And some how they will support 300HP+ easily.

How can you be sure about the flow routing without cutting away to the ends, to see what's in the other two chambers?

PS - love your title! joker

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown
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IBx1
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyMon May 30, 2011 11:49 pm

Wow, not the most efficient design but I see how they made the 3800's quiet!
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 12:01 am

AA wrote:
And some how they will support 300HP+ easily.

How can you be sure about the flow routing without cutting away to the ends, to see what's in the other two chambers?

PS - love your title! joker

Its hard to tell from the pic,but at either end of the muff,there is a hole about 11/2" dia.its all that allows the exhaust to escape through the tip...
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 12:04 am

This thread title had me hoping for more exciting pics. Interesting though, explains why I noticed that I can hear birds chirping in the morning while I cruise to work....
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AA
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 2:26 am

I gotta play devils advocate...

I can't tell if the design is efficient or not just from looking at pics, but I'd bet a pound of pork the guys at GM knew a few things about exhaust when they engineered it. Or they outsourced from a 3rd party who specialized in exhaust design. It had to be quiet, but it also had to flow some serious air, and it had to last.

What's interesting to me - here's a picture of a Dynomax Super Turbo muffler:

FAQ: Mufflers? - Page 8 Superturbo_lg

Look familiar? Dynomax says: "Exclusive patented flow director design channels exhaust flow and eliminates turbulence."

Check out this Thrush HUSH Super Turbo muffler:

FAQ: Mufflers? - Page 8 Muffler

Thrush says: "The improved tri-flow design of the Hush Thrush™ Super Turbo™ enhances flow and performance."

I'm seeing a reoccurring pattern, and knowing our OEM design is so much like the aftermarket versions makes me like it even more. I also like the fact that our mufflers can last forever. If I had a reason to replace them I might, but I've never seen any rust on any of the stock exhaust parts.

Years ago I asked Todd Allen at INTENSE Racing about the stock exhaust on our cars. He drove an '00 SSEi, which happens to have a system nearly identical to ours, right down to that evil "T" split everyone raises hell about. So I asked Todd, "how much power can you make with stock cat back?", and he told me without question: "400 HP".

Four hundred horsepowers can squeeze through those two little stock mufflers! How did Todd know? He dyno tested each stage after 7 stages of serious mods, from stock 240 HP all the way up to 466 crank HP. After the 6th stage he had the following mods: AL104 plugs, 160º t-stat, 4" FWI with K&N cone, PCM tune, Stage 1X cam, Gen V blower w/intercooler, 2.6" pulley, balance shaft delete, SLP headers w/high-flow cat...

...and still totally stock after the cat. The dyno run showed 423 HP at this point. Todd finally added a full 3" exhaust system with stage 3 heads to pick up another 43 HP. The heads alone are advertised for 30-60 HP alone (depending on other mods), so you have to stop think how much of that last 43 HP can be attributed to the major exhaust upgrade.

Anyway, thanks for the pics. Sometimes looks can be deceiving!

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown
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robotennis61
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 2:57 am

No doubt the design is a sound one.no discussion there. The above pictured muffs,have larger than OEM, tubes.The school of thinking is,On a SC'd car,the faster you can expel exhaust gasses,the better your engine will perform.A SC'd engine is not as sensitive to exhaust pressures as a turbo system.So...the faster air moves in and the faster it goes out..the better. Can OEM support 400hp? sure,why not. but if you can have your engine operate and breathe a little easier..why not? all it needs afterwards is a little tweaking of the FI system and voila!
Again,the above designs are exactly like ours.only ours doesn't have batting inside,and the perforations are smaller.I will get rid of my current muff which is a Thrush Welded and ..STUPID LOUD AND DRONE CITY!! wish I had a video cam with sound.A cherry bomb as a rez and the Thrush,it dont sound bad at all.very muscle car like with zero rasp or backfire....I'll be getting a Thrush Hush Turbo..
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IBx1
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 9:04 am

Seeing the flow diagram reminds me of the Mugen Twin-Loop muffler for my car:

FAQ: Mufflers? - Page 8 Mugen_sports_silencer

I can't find any cutaway pictures(they're expensive as hell so I'd imagine nobody wants to chop one up instead of selling it off), but it's easy to see where the exhaust goes. That's one of the deepest and richest sounding mufflers for a Honda because of the double flow. Makes them sound like Subaru's at idle. I'd get a video to show ya but I know how much you guys like Honda videos... tongue
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Karma
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 9:24 am

IBx1 wrote:
That's one of the deepest and richest sounding mufflers for a Honda because of the double flow. Makes them sound like Subaru's at idle. I'd get a video to show ya but I know how much you guys like Honda videos... tongue

Little cars shouldn't have deep voices. It is like its pretending. wink


And robo, you should seriously try the Dynomax VT's. It sounds amazing, subtle muscular rumble, unbelievable flow, and yet doesn't scream "I HAZ EXHAUSTS!" like a poser.

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Last edited by Karma on Tue May 31, 2011 10:50 am; edited 1 time in total
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FAQ: Mufflers? - Page 8 Empty
PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 10:33 am

That Mugen pipe appears to me an example of marketing brilliance. If you want an exhaust that sounds like a 'symphony', might as well model it after a brass instrument, right? It's more expensive because the fabrication involves more operations, but they have a market who's willing to pay for it. A competitor could probably achieve the same results using the classic oval package, and sell it for less, but that just wouldn't be any fun!

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown
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IBx1
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 10:52 am

Karma, it's not necessarily that the exhaust sounds ultra low, but that it doesn't have the Honda fart at all. Sounds like what they all should sound like, nice and rich.

Aaron, as a matter of fact, while Mugen made the original design, there's a company called OBX that sells them for almost a tenth of the price. Mugen wants $650, and you can find an OBX for $75. I'd never sink my money into Mugen parts, but there's definitely a market for their stuff. Otherwise they wouldn't sell so many $60 oil and radiator caps! The shape looks a little sloppier on the loop pipe but nobody sees that. I like how both of them have stock-looking exhaust tips:

FAQ: Mufflers? - Page 8 L_a994ad4bf141c5f60f3e3a8711e09b86
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 11:06 am

Sourcing from China is one way to cut costs by 90%. Keep in mind, the Mugen tech who sets up the jig to weld that pipe probably gets paid $50/hr. The chinese copy cat might get $2 to do the same job.

I don't know why nobody likes the raw Honda sound. Our Integ sounds very nice with only a straight pipe and a small resonator upstream.

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown
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robotennis61
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 12:07 pm

Karma wrote:
IBx1 wrote:
That's one of the deepest and richest sounding mufflers for a Honda because of the double flow. Makes them sound like Subaru's at idle. I'd get a video to show ya but I know how much you guys like Honda videos... tongue

Little cars shouldn't have deep voices. It is like its pretending. wink


And robo, you should seriously try the Dynomax VT's. It sounds amazing, subtle muscular rumble, unbelievable flow, and yet doesn't scream "I HAZ EXHAUSTS!" like a poser.

I just might at that. I do like the price of the Thrush though,I think maybe the price of the VT will come down some soon...And I converted to a single muff system.The two just seemed redundant...
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 12:18 pm

That's probably what I'd do, if I ever decided to upgrade. One pipe seems more 'honest', although I do like how the faux duals add more weight to the extreme rear.

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 12:47 pm

robotennis61 wrote:
If anyone was curious to know how restrictive our OEM muffs were,here ya go....

FAQ: Mufflers? - Page 8 HPIM1163

I'll Tell you,there is no other opening to the exhaust tip,than through these tiny perforations.No slot for the bulk of the exhaust to get through.Nothing.

Please also show us what's on the ends.

Albertj
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 1:51 pm

The ends are just where I cut it off from the exhaust pipe.the portion of the muff that is behind the inner exhaust tubing is exactly like the pics of the dynomax muff that AA posted
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 2:05 pm

robotennis61 wrote:
The ends are just where I cut it off from the exhaust pipe.the portion of the muff that is behind the inner exhaust tubing is exactly like the pics of the dynomax muff that AA posted

Thanks, that helps.

By the way, what about the sections on the interior of the muffler that are hidden by the oval steel panels that hold the tubes (the inner exhaust tubing supports) and the sections of the muffler skin that you did not cut off? What is in there? Or is that what you are saying is exactly like the DynoMax?

Again, thanks.

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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 2:29 pm

here are a couple more pics. of either end.It shows how the gases get circulated....

FAQ: Mufflers? - Page 8 HPIM1165

FAQ: Mufflers? - Page 8 HPIM1164

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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 2:58 pm


Thank you thank you -- that helps a bunch!

When you look at the pictures - what they've (probably Arvin Meritor, who is an exhaust supplier to GM) has done is tuned the openings to resonate/cancel in interesting sound frequency ranges. The gases flow into/thru the far (outlet) end chambers primarily. But the tube that would scavenge most of the gas extends very far into that chamber. It would tend not to "hear" the inlet tube - kinda like if you listen thru a paper towel roll you won't hear much that the roll is not pointing towards... The exhaust inlet is necked down which would increase gas velocity s bit while also damping and focusing the sound. Gas and sound hit the perforations in the tubes, but the perfs would tend to dissipate the sound actually, not very much gas at all will flow thru the perforations. The flare (increase in diameter) on the outlet is probably what gives the exhaust the "burble" at idle. Basically the muffler is a horn that plays the note the exhaust is tuned to given the engine's input (the exhaust and noise from combustion) at idle. That output note changes with RPM but would be the "burble" at idle so to speak.

It's pretty cool - basically you could think of it as a set of organ pipes that are detuned to pass (exhaust) gas and not play the dominant resonant note -- which when you put a straight pipe in in place of the resonator the dominant note is the "drone."

Again thank you!

Albertj
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 3:29 pm

This shows exactly why it's so difficult to build a custom free-flowing exhaust that's also whisper quiet. It also shows that it's quite possible to do with research, design and proper execution (there is a belief that you MUST have noise to make power - this is not so). As albertj indicated, the chambers are tuned. This has to do with the relationships between the length & widtch of each tube, and the volumes of air each chamber. It's a type of bandpass helmholtz resonator, and it must be specifically tuned to match the resonant frequency of the system, or the drone frequency.

I believe the OEMs are tuned specifically for our cars, whereas the aftermarket super turbo style mufflers are tuned for a range of probable frequency. That explains why you gain sound level (drone) with the aftermarkets, and it explains why one model may sound quieter than another on a specific car. While flow is increased, so is the sound, but it's not a result of more flow, imo. It's the result of the tuning being off - because it's made for an average target, and that target is likely a V-8.

Here's a really good idea that lets you tune the muffler on the car while running: link

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch

^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 3:54 pm

AA wrote:
This shows exactly why it's so difficult to build a custom free-flowing exhaust that's also whisper quiet. It also shows that it's quite possible to do with research, design and proper execution (there is a belief that you MUST have noise to make power - this is not so). As albertj indicated, the chambers are tuned. This has to do with the relationships between the length & diameter of each tube, and the volumes of air each chamber. It's a type of bandpass Helmholtz resonator, and it must be specifically tuned to match the resonant frequency of the system, or the drone frequency.

I believe the OEMs are tuned specifically for our cars, whereas the aftermarket super turbo style mufflers are tuned for a range of probable frequency. That explains why you gain sound level (drone) with the aftermarkets, and it explains why one model may sound quieter than another on a specific car. While flow is increased, so is the sound, but it's not a result of more flow, imo. It's the result of the tuning being off - because it's made for an average target, and that target is likely a V-8.

Here's a really good idea that lets you tune the muffler on the car while running: link

The 'cool' thing for me is it looks like speaker enclosure tuning, which I know how to do - but also involves fluid flow (exhaust gas) tuning which I do not really know how to do. However, looking at the cutaways, I see what's going on. The Corsa exhaust, for instance, uses a more complex Helmholtz adding cost (albeit modest) and weight (which might not have been a bad thing except for the fuel economy implications). Again, thank you Robo.

A side note - this also explains to me why my retrofitted OE PA exhaust has bigger mufflers than the OE Riv does, and why it does not seem to have that "flat spot" around 2000 - 2500 RPM like my original Riv mufflers had. The PA internals are probably a similar setup to the Riv but tuned to pass all the gas and then some without making any sound worth a darn. The necking inside the muffler inlet on the Riv exhaust is a modest restriction but they probably *had* to do it to get the sound right and for just about everything but racing it would not matter. On the PA exhaust they used very heavy end plates on the mufflers and put ribs in those plates, I suspect to get rid of (via conversion to heat) that last little bit of sound from the inlet pipes.

I can also see that on a less expensive car, cost would dominate performance and hence a "Tuner" who does not care about drone and noise within legal limits can likely get more whizz and boom out of certain 4-banger cars with almost any exhaust upgrade.

Albertj
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deekster_caddy
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 4:50 pm

AA wrote:
This shows exactly why it's so difficult to build a custom free-flowing exhaust that's also whisper quiet. It also shows that it's quite possible to do with research, design and proper execution (there is a belief that you MUST have noise to make power - this is not so).

I can't tell you how true this is. The biggest challenge we face with the 455 in my brother's Buick is keeping it quiet. We tried several different mufflers, unfortunately gave up before we found a satisfactory sound level. It's very very hard to keep quiet when you have 455 cubes, a big cam, long headers, running crisp and a little lumpy... but what we've done is not too shabby.

It's annoying how many people prefer the noise.
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BMD
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyTue May 31, 2011 8:38 pm

Thanks for the pics robo, very interesting.
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PostSubject: Re: FAQ: Mufflers?   FAQ: Mufflers? - Page 8 EmptyWed Jun 01, 2011 4:13 pm

Welcome!I kept the right side muff.Really all I have to do is weld on 3" Inlet/outlet tubes,enlarge the stock perforations,and ill have a stainless steel/OEM modded muff! for free.
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