JetMech99

iTrader: (3)

Used the search and didnt see anything on this, but does anyone have any info regarding the flow #s of the different bullet mufflers on the market?

Right now im runnin LTs/ORY and Loudmouth. I hate the sound but i dont want to lose any HP, nor do i want to get a cutout.... but something has to be done about the sound. Im not lookin for a quiter setup, just less rasp, and a deeper sound.

I know the ones most guys are going with right now, but do they flow as good as the Loudmouths resonator? Thanks to anyone who takes the time to respond!

300bhp/ton

Flow numbers are hard to come by, this is due to there being no standard on how to acheive them. So sadly you can not directly compare all of the numbers you may find, although they should give an idea.

Common mufflers to use are Dynomax bullett, Borla XR-1 and Magnaflow bullett.

An alternative option:

Did you like the sound of the LM when you had cats? If so then adding some highflow cats may be the answer as they will reduce the rasp and keep the sound.

IMO - Maganflow Carsound cats will be fine on bolt on cammed LS1. If you plan on bigger power than that then Metal Matrix cats (Random Technology 7000 Series) would be a better bet but they are pricey.

JetMech99

iTrader: (3)

Thanks you kindly sir, and good point about there being no standard on which to test them.

Also, i know it sounds cheep, but id hate to spend the money on high flow cats, only to lose HP.

The reason i started thinking about this is i called the guys over at Sweet Thunder, and he was talking me out of their product saying the 2.5" inner diameter would not flow very well on the LS1. I would hate to give up HP for sound, but it is unbearable at times.... ill search for sound clips and keep researching. Thanks again!

NxLS1496

iTrader: (1)

i plan on with going with the borla XR-1 when i get my headers. i havent seen flow numbers, but as long as its a bullet muffler its going to be a sraight through design and the most you will lose if any at all couldnt be more than like 5hp.

Ric

I remember a post on here comparing flow at 28" of water, with 2 1/2" muffler, compared to a 2 1/2" straight pipe of same length. Dynomax bullets, Magnaflow bullets, and pretty much any muffler that went straight thru using perforated tubing flowed the exact same as the straight pipe.

SUTTERERMAN85

iTrader: (42)

about the same as the same dia pipe lol

300bhp/ton

That's not exactly accurate as glass pack (or metal fibre) mufflers affect the exhuat pressure wave so they may have a more dramatic result on HP.

300bhp/ton

For any muffler you get I would recommend a 3" core and inlet/outlet for any muffler you look at.

Maybe using some Powersticks from Classic Chambered Exhaust would be an option, these are like what GMMG use but they don't neck down and flow very well, they are also cheap.

You'll need to use Google to find their website, or failing that PM me.

Italiano99

search dynomouth (dynomax) in the threads, Iv'e heard good things about them. I currently have LM and am ordering Pacesetter LT's and ORY. For now Im gonna leave it like that but I bet eventualy (month or so) Ill want to tone down the rasp.

GuitsBoy

iTrader: (4)

Youre not going to see any loss in power with a bullet. If anything it probably flows bettwe since the pipe dosnt expand and then contract again like the resonator.

kenkaru

FYI,
There's basically nothing inside a bullet muffler. If it weren't for the weld bead, you could slide a piece of 3" pipe right through a 3" bullet muffler. I'm thinking you've never held one in your hand or you wouldn't be asking about flow comparisons.

I've had good luck with dynomax bullets.

300bhp/ton

That's not accurate, a bullett muffler does expand exactly the same, only it isn't hollow it has some form of packing, often glass fibre or metal weave.

As the gas enters the muffler it expands thru the holes in the core and some of the gas will enter the packing, this will slow down and muffle the gas and noise so they will affect flow over a smooth pipe.

But such mufflers also affect the exhaust pressure wave also, try the sticky in this forum about Exhaust & Intakes, I think post 13 is the one to read it's written by a chap called David Vizard and is well worth a read.

GuitsBoy

iTrader: (4)

But theres a perforated core with the packing materials. If anything, ill bet these perforations create a boundary layer much the way the dimples on golf ***** do.

Im not claiming that it will flow better than a smooth pipe of constant diameter, however IMO a pipe of varying diameter would likely create turbulence in the case of a resonator. To be perfectly honest I dont there being much of a difference between a resonator and a bullet muffler, but I think youll have a hard time finding any other style of muffler that comes anywhere close to flowing as well.

300bhp/ton

But they aren't perforations like on a golf ball they are holes like on a cheese grater. It's like if your garden hose gets a small hole in it, even with water flowing thru it at speed it will still expand and spray out of the hole, a bullett muffler does the same, the gases expand into the entire chamber, this is how they acutally function, if the packing around the outside didn't do anything and the gases didn't enter it it simply wouldn't be part of the muffler.




Bullet muffler:


But as stated above bullett mufflers do vary in diamter in exactly the same manor.

Straight thru bullett mufflers should flow well (I run them on my TR7), but length and packing diamter will affect flow and noise supression, a 3" core and a 4" diameter muffler means only 1/2" of packing, it will not have much affect on flow or noise supression. A 3" core with a 6" diameter muffler has 1.5" of packing, essentially 3 times the amount even though it is only twice the width.

There are not many, but some chambered muffler can and do, sadly a visual look does little to tell the sorty of fluid dynamics and they are what you'd call comlpex.

Powersticks are reputed to flow very well, but they are a straight thru chambered muffler that use the deflection method of noise supression as opposed to the absorbtion method utilised by bullett mufflers.

GuitsBoy

iTrader: (4)

The garden hose has a pressure differential across the pin hole. The bullet muffler does not, since the gasses dont vent to the outside. Ill concede that as the exhaust pulese travel through the muffler, you may have a little bit of movement of air on the matting side of the perforations, but for the most part, it should pressurize to the same average pressure as the inner core exhaust.

Sound waves do not travel linear in fashion like exhaust flow does. The sound waves could easily traverse the core perforations to be broken down by the deadening (reflected waves cancelling eachother out). Exhaust flow however shoudl have the same pressure on both sides of the perforated core, and the exhaust should not actually have to flow through the deadening material.

I am curious about the chambered mufflers that can outflow flowthrough designs though. Do these work on a scaventing effect of some sort that only works at tuned frequencies? It seems like the only way to outflow a flow through design would be with a tuned pipe that helps at one certain frequency, but then hurts all others.

BTW, please dont take any of this as a pissing contest. Im not trying to win some sort of forum argument. Just stating my own understanding and opinion of things. Going back an fourth on some of the finer points will help bring the details to light.

Thanks,
-Tony

300bhp/ton

Nah this is all cool it's how we learn new stuff. I hear what you say and agree with most of it, although I'm sure the exhaust pressure wave must interact with the packing material or else this type of muffler wouldn't have any affect on it, but it does (well according to David Vizard and he's far more intelligent than I am).

I'm not certain that any chambered muffler really outflows a bullett, but they can flow well. Technically the SLP LM Resonator is a form of reflective chambered muffler.

It's not a very good picture, but these look like the mufflers used on the GMMG on the outside, as you can see it is straight thru also and it has perforations which are used as reflectors for noise supression. Just like a small bullett muffler their ability at noise supression must be limited.

kenkaru

Exactly.
If you dug a hole in the bottom of a river, it would just fill up and the water flowing over the hole would only get very slight turbulence.

It's important to remember that there are two seperate things going down the pipe.
1. Sound
2. Exhaust fumes
and they travel in different ways.

When sound waves meet eachother, they don't bounce off one another, they mix and (preferrably) cancel each other out.

I'm sure an engineer is going to come in here and blast all of us to kingdom kum with all kinds of ridiculous mathematical computations involving the boiling point of aluminized steel and the speed of light divided by the age of the universe

GuitsBoy

iTrader: (4)

Right, IMO, its not the exhaust pressure that travels through the packing material, its only the sound vibrations. The overall larger flow of exhaust goes straight through the tube. The noise vibrations (microscopic compression waves) far too tiny to significantly effect the internal pressure, and furthermore, theyre balanced bidirectioanlly. For every compressed sound wave, theres an equal expansion (wave trough) so it has no net movement. Does david vizzard have any reading material published online?

Also, the GMMG style chambered muffler should impact the flow moreso than a bullet since the perforations actually scoop the exhaust flow. Its not a straight through shot. because the scoops are actually redirecting the flow, i could see atleast some exhaust gasses passing through the deadening material.

300bhp/ton

David Vizard has several books in publication and many articles across the internet. He writes for Popular Hot Roding and Engine Masters also (http://popularhotrodding.com/enginemasters/articles/)

Plus he has been involved with many companies/teams over the years developing exhuasts/mufflers.

lilbuddy1587

iTrader: (1)

http://www.torquetechexh.com/powersticks.htm to order the powersticks
http://www.classicchambered.com/ to learn more about them.