Which Performance Muffler Design Is Best?
Car engines produce extremely loud sounds during operation, and without some sort of sound deadening device (aka a muffler), your vehicle would be unbearably loud to operate. Anyone who has been to a drag race will attest to that fact that most dragsters are incredibly loud, and this is because they don’t have any sort of muffler.
When shopping for performance mufflers, you will hear manufacturers argue that they have the “best” design. However, is one performance muffler really better than another? The answer to that question starts with a little background.
How A Muffler Works
Internal combustion is essentially a series of controlled explosions. Each of these explosions has a shockwave that travels out of the engine and into the exhaust system. When a shockwave enters the muffler, three things happen:
- The shockwave is bounced around against the walls of the muffler and against itself through a series of baffles, which causes the shockwave to lose energy.
- In almost all mufflers, the shockwave must also travel through a sound deadening material (usually fiberglass fibers) which absorbs the most extreme sound frequencies.
- Most mufflers have more than one chamber, and as the shockwave travels between and through the different chambers it’s broken up into pieces. This changes the wavelength and frequency of the sounds in the shockwave, which helps reduce it’s energy and harshness.
Put another way, a muffler is like the pool at the bottom of a waterfall. A massive stream of loud, boisterous water falls in, but a slow, steady stream of water flows out. The key to designing a muffler is understanding how best to contain each shockwave without limiting the flow of the hot exhaust gases.
Performance Muffler Design – Which is Best?
Most mufflers use a combination of sound reflection and sound deadening to control engine sounds, but some rely exclusively on one method. Some muffler manufacturers will advertise the fact that they don’t use any baffles, saying that they use a “straight through” design that doesn’t interrupt airflow. Other manufacturers advertise the fact that their systems don’t rely upon cheap sound absorption materials, and are therefore likely to last longer and sound better than the “straight through” designs.
Truth be told, there are no significant performance benefits to either design – at least not compared to the way the system you use has been tuned. If the manufacturer that designed your muffler tuned it specifically for your vehicle, you will enjoy better performance than someone who buys a “universal” muffler that isn’t tuned to your specific application.
So, the bottom line is, if you’re considering a performance muffler, don’t buy the hype. Design doesn’t matter as much as tuning. What’s more, whether you’re buying a performance muffler or just a factory replacement, look for the best warranty you can afford, stainless steel, and a brand name you can trust.
HI Jason,Thought Id comment on this one as most muffler manufacturers produce flow ratings done on a bench however flowmaster doesnt do this and use real life testing on their mufflers but when tested for flow by others they seem to flow less than other manufacturers products and yet produce the same horsepower so in your opinion are flowmasters as good as the best straight thru designs ? Michael
Michael – I’d say that the major brands are all pretty equivalent, even though they all claim to use a different design/concept. Based on dyno testing I’ve done on Tundra pickups with different systems for TundraHeadquarters, and long conversations with a couple of really experienced muffler shop owners, I feel comfortable saying that the biggest difference is *tuning*. If you buy a system tuned for your year, make, and model, you’ll get better results than a system that isn’t tuned, or with a generic muffler.
I drive a 2000 civic and a 91 240sx. I have ran regular mufflers and glass packs on both. Aside the noticeable noise difference I find the glass pack gives a little more pickup. Not sure if i it is just me or not. Any information would be appreciated. Another question I have is placement of the muffler/glasspack. Does putting it in the middle any different than putting it at the end? An answer to this question will help with my 240sx. Buying a 4-1 header, and the outlet is 2.5 inches. So from there only thing left would be muffler/ glasspack. The cat is toast. I appreciate any input given. Thank you. – Colt
Colt – While I’m sure there’s some impact from moving the muffler closer or further from the engine, I doubt it’s significant to move it a couple feet in either direction. Most of the time, muffler placement is dictated by the design of the vehicle itself. SO, put it where you have room for it, and ideally where the temperatures from the exhaust have fallen just a bit…a couple feet behind the output of the collector ought to work.
As for glass pack vs other muffler designs, it just depends on the specifics. Glass packs are similar in design to oval shaped mufflers, so it’s not like they’re incredibly different. It’s also hard to trust the old “butt dyno” for this sort of thing… 😉
I have done quite a bit of research as far as the physics go. As for exhaust that has no muffler; the shorter the pipe and smaller the diameter the higher the frequency the exhaust is going to produce. The longer the piping and larger the diameter the lower the frequency the exhaust is going to produce.
The majority of picking exhaust is based on how much power you are actually making then pick the appropriate diameter. then based on that diameter you can then pick your exhaust length (within reason) to promote either a higher frequency of a lower frequency note/tone/etc the exhaust is going to create.
X pipes (in relation to dual header engines only) will help connect the exhaust pulses much like a 180 degree header although not as efficiently. The issues with 180 degree headers are:space for the header, heat produced, and limit of rpm of motor to about 6400 rpm. The x pipe tends to make the exhaust sound a bit more exotic, crisp, modern, and to be blunt running properly. That Harley (Porsche motor) that most people are in love with technically barely runs on paper.
The h pipe does connect the exhaust but doesn’t efficiently enough connect the exhaust pulses to help make that European sound the x pipe creates.
As far as the muffler goes the best design I have seen is the Corsa sport design. Google a cutaway of a corsa sport muffler to see exactly what I mean. As for sound goes they attempt at making the vehicle sound less like a dump truck and more like an actual race motor. The next best I have seen is Borla. Borla has a bit deeper tone than the Corsa systems/mufflers although they are rather efficent. As far as any other muffler, unless it is a straight up race muffler, you are restricting the exhaust significantly.
Last but yet first. people always forget that the header is the most important part of the exhaust system. If pipe length and sizing one should google “headers by ed” ed (who i have had a number of conversations with) has had a large amount of experience in had making efficient headers. he no longer makes headers unfortunately he is retired. the single most important part of a header is to make sure that the primaries are of equal length. If you keep that in mind the rest is significantly easier to figure out.
Also as a side note. If anyone here hears of any sporty exhaust (akin to the corsa sport system, or much alike the Eisenmann race exhaust) please post the name of the muffler company. Something unfortunate is that there are very few companies who make mufflers only that sound like a real race car.
http://www.youtube.com/watch?v=xCtJVbJEHZg
here is an example of exhaust on a 90 degree cross-plane crankshaft v8 bmw, this is the best exhaust I have ever heard/seen. It is simply too bad that they do not sell just mufflers, you have to buy the entire exhaust system. I don’t recommended exhaust systems, rather something you have come up with yourself using the frequency equation.
Jason, I wanted to ask one more question about the exhuast system I have. As I had posted in the other article I had a dual 3″ exhaust system. It is a lot louder than I wanted, especially at idle. I know now a lot of that is to do with it being 3″. I am currently running 14″ body Dynomax UltraFlows (offset/offset). The manufacture of my exhaust system recommended putting some resonators on the tail pipes. Would I be better off changing mufflers or try the resonators first? Thanks again!
taylor – Resonators are probably a better option, as most after-market performance mufflers are loud out of the box. Switching might not get you the change you’re looking for.
Jason, I added a set of 20″ resonators basically right before the tips on the tail pipes. While they did help, it is still louder than I wanted and drones at cruise which is annoying. I am debating trying different mufflers but I am concered about performance. I am currently running Dynomax Ultraflo (straight through design) mufflers but was thinking about trying the Dynomax Super Turbo (chamber) mufflers. Will I lose power/hurt performance if I switch to these mufflers? Do you have any recommendations? Thanks!
Taylor – Generally speaking, mufflers have a minor impact on performance unless they’re part of a tuned system. Unless you’re driving a vehicle with a tuned cat-back, I think swapping out mufflers is fine. It’s hard to notice a difference from one muffler to the next (again, unless that muffler is part of a tuned cat-back system).
Thanks Jason, any recommendation on a quieter muffler for my setup? I know 3 inch will always have that low “boom”, again over kill for my application, but hoping to get that cruise drone gone. I am restricted on space, here are the specs for my current muffler: http://www.summitracing.com/parts/wlk-17229
taylor – Not really. I’d buy a muffler that billed itself as quiet or drone-free, but in truth most “drone-free” mufflers aren’t drone free. Sorry I don’t have a better answer…