FAQ: Mufflers?

robotennis61 wrote:

A pretty righteous setup Turtleman! with the single muffler,do you feel that you lost anything in the way of performance? I'm almost sure that the dual exhaust of the riv is for looks only. and have you thought about switching the muffler for a dynomax VT? the one with the internal gate? that muffler might solve alot of the rivs raspy sound. Karma's sounds really good.

I still have that setup now except redone nicer and more permanent with a hooker dual tip. up to date picture of back end
As far as performance, I have no evidence to say it's more restrictive to the engine than anything else I've had before with duals. It's a big-ass muffler and has a 3" inlet pipe.
I like the idea of the VT muffler a lot but I'm actually happy with this because it has a real rumble to it while idling that I don't think the VT would give.

side note. When I visited PRJ Paul last monday, we took his GTP into town for my parts and it sounded very good with Borla proXS mufflers on it. It was loud but not overly loud and sounded pretty good with throttle - not raspy. I know it has no cat or resonator and I would assume it's got headers if it's Pauls. If you're lookin for something on the louder side but not ridiculous, I'd say those are a very good choice based off that.

tanks buddy!

turtleman wrote:

When I visited PRJ Paul last monday, we took his GTP into town for my parts and it sounded very good with Borla proXS mufflers on it. It was loud but not overly loud and sounded pretty good with throttle - not raspy. I know it has no cat or resonator and I would assume it's got headers if it's Pauls. If you're lookin for something on the louder side but not ridiculous, I'd say those are a very good choice based off that.

Codith,
What work were you having Paul from PRJ do to your car.????/

Rickw wrote:

turtleman wrote:

When I visited PRJ Paul last monday, we took his GTP into town for my parts and it sounded very good with Borla proXS mufflers on it. It was loud but not overly loud and sounded pretty good with throttle - not raspy. I know it has no cat or resonator and I would assume it's got headers if it's Pauls. If you're lookin for something on the louder side but not ridiculous, I'd say those are a very good choice based off that.

Codith,
What work were you having Paul from PRJ do to your car.????/

I had a set of bare fuel rails and regulator that we had to custom plumb, also a lookover on my tune.

How did all that work out.?

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







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.

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!

Wow, not the most efficient design but I see how they made the 3800's quiet!

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!

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...

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....

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:



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

Check out this Thrush HUSH Super Turbo 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!

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..

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



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...

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...

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


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.

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!

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:

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.

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...

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


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...

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.

robotennis61 wrote:

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



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

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

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.

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

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