If there’s one commonality amongst Harley-Davidson owners (other than they love their motorcycles) it’s that they are never satisfied with their motorcycles. I don’t mean never satisfied in the sense that they can’t stand riding it, I mean never satisfied in the fact that there is always something they want to modify, customize, or change. Even rolling a brand new bike off the showroom floor and firing it up for the very first time leaves something to be desired; there’s something missing and it can usually be traced to the stock exhaust system. From the factory the exhaust system is set up to meet strict government and sometimes state (California we’re looking at you) regulations for both sound and emissions. And with meeting those regulations comes stuffed up systems that don’t look, sound, or perform the way many Harley owners would like. Therefore the stock exhaust is typically the first thing an owner will change on their bike.
With new exhaust manufacturers and different types of systems popping up almost every month, trying to find the one you like can be overwhelming. But what it really comes down to is four determining factors: How much are you looking to spend? Is there a certain style you like? Are you aiming for a specific sound? How important is performance?
Style is completely subjective. What appeals to one Harley owner may be a complete turn off for another. The good thing is there are a myriad of styles to choose from starting with pipe configurations like True Duals, 2-into-1, and 2-into-2s to muffler styles such as slash-cut, fishtail/sharktail, turndown, and megaphone just to name a few.
True duals describe a full complete exhaust system in which the mufflers exit on either side of the bike. Many bagger owners like true dual systems like the Racing True Dual System from Freedom Performance because it gives their motorcycle a balanced look with mufflers tucked under each saddlebag. True duals allow for a wide variety of muffler options, and in many cases when it comes to touring models you can often mix and match mufflers and head pipes from two different manufactures to get the exact look or sound you want.
A 2-into-1 system means that the head pipes coming off the front and rear cylinders meet together in a collector creating a single exhaust exit on one side of the bike. When you come across a 2-into-2 exhaust system for a Harley-Davidson motorcycle it typically means that the head pipes are completely independent of each other. However, unlike true duals where you have the pipes terminating on either side of the bike, with a 2-into-2 system both pipes stay on the right side of the motorcycle. You may come across an exhaust system described as 2-into-1-into-2. This is typically common on most stock Harley exhausts. Basically this system looks like a dual or True Dual system, however, there is a cross over tube that allows the exhaust flow to merge together and then disperse through separate mufflers.
When it comes to touring models there are a couple of styles of true duals that you can choose from. In 2009 Harley came out with a new frame design and along with that they addressed excessive heat issues felt by the rider and passenger by rerouting the head pipes. Instead of the rear pipe splitting into two with one side coming down along the left side of the bike and the cross over tube routing down across the back of the transmission on the right side of the bike to join into the front head pipe, for 2009 Harley routed a single rear pipe to come down and forward, ahead of the transmission, on the right side and then joined into the front head pipe. The front pipe then drew across the underside of the frame and then was routed under the left side saddlebag while the rear cylinder was routed under the right saddlebag.
This new 2-into-1-into-2 design helped pull the hot exhaust pipes away from the legs for a more comfortable ride. Many aftermarket exhaust manufacturers have followed suit with their own designs creating similar solutions. One example would be Freedom Performance with its Right Side Tuck and Under system. There are a couple differences between Freedom’s exhaust system and the stock unit. First, Freedom’s is a True Dual system with completely independent pipes for both cylinders. Secondly, the stock cross under tube has been squeezed to provide more ground clearance, while Freedom’s cross under tube is a full diameter tube and still maintains proper ground clearance.
If cost is a primary concern then your best bet is to look for a set of bolt-on mufflers to mount to your stock headers. Since you’re only replacing the system from the end of the head pipe back, there is less material and manufacturing involved making mufflers less expensive than buying a full system. The great thing about mufflers is no matter if you have a Dyna or a bagger, there are a wide variety of styles to choose from. If you go the slip-on muffler route you need to make sure that whatever you select will fit up to your stock head pipe(s) or whatever head pipe(s) you plan to use. A simple slip-on install is quick and easy and will help allow for better exhaust flow resulting in a slight gain in horsepower and a new exhaust tone.
If money isn’t a factor then a full system should be considered. A properly tuned full system will deliver significantly more performance than just a set of slip-ons and will set you up to be better positioned for optimal performance as you continue to hop up your powertrain. Just like slip-on’s, full systems are available in a variety of different styles (2-inot-1, 2-into-2, True Duals etc.) as mentioned earlier. Some full or complete exhausts, like the Independence Shorty Complete Dual Exhaust system by Freedom Performance, are one-piece units in which there are no separate mufflers to install. This makes for a much easier and faster installation as compared to a True Dual bagger system that has a combination of head pipes and mufflers.
Other factors that can affect the price of an exhaust system are things like heats shields, finish, and the type of material it is made out of. While the majority of exhaust systems sold these days come complete with all the mounting hardware and heat shields you may run into a couple here and there where heat shields are sold separately, so it’s important to thoroughly read through the product description and understand exactly what you are getting. While most mufflers and complete systems are offered with a chrome finish, some give you the option of choosing a high temp ceramic finish which will usually cost a little bit more than chrome. You’ll mostly see black ceramic but some companies will offer other color options like silver ceramic as well. Many people choose the black ceramic because they like the look, but it is also highly durable and capable of maintaining its look in high heat situations. Chrome can sometimes turn blue or take on a golden brown hue over time or with a poorly tuned motorcycle that emits excessive heat. Ceramic coating also helps reduce radiated heat to the rider and offers some performance benefits in the fact that it helps maintain even exhaust temperature for better flow.
If you really want to spend a pretty penny, then you might want to consider something like stainless steel, titanium, or carbon fiber motorcycle pipes. In order of cost between the three, stainless steel exhaust systems are the least expensive then you have titanium and then carbon fiber. There is a caveat to this however, as you‘ll typically only find carbon fiber available in mufflers/collector or heat shields.
Just like style, the preferred exhaust note is subjective. Some people want a deep rumble while others might want more of a raspy tone. Simply installing a set of aftermarket slip-on mufflers can drastically change the sound of your exhaust note from a light rumble to a hardcore bark. There are many factors such as overall design, pipe diameter, and baffle length that can have an effect on the sound produced. One thing is for certain, drag or open pipes with no sort of baffling will produce an extremely loud tone that will resonate well beyond your immediate area. If this is something that appeals to you then prepare to either ride at the back of the pack or all alone as not everyone likes to be tone deaf after a motorcycle ride. If you live in a suburban type neighborhood or apartment complex and keeping a low profile is a major concern, then you may want to look for system/mufflers that can work with quiet baffles. Vance and Hines offers quiet baffles that will simply slide in place of the standard baffle and will knock a few decibels off the overall sound. Your best bet is to keep an ear to the air and listen for the sound you like and then get the same system or something really similar in style. However, keep in mind that things like internal engine mods and the type of engine can make a difference as to how a full system or mufflers can sound.
When it comes to performance you could spend countless hours reading and researching all about exhaust theory in regards to pulses, exhaust scavenging, reversion etc. Once again there are many factors that can have an effect on how a motorcycle exhaust performs. Things such as style (2-into-1, true duals, etc.), pipe diameter, number of steps in the header, header design, pipe length, muffler/collector design, and engine mods can determine performance. In the simplest terms you’ll see a slight gain in horsepower and torque numbers just by bolting on a set of slip-on mufflers to your stock headers. Offering better flow than the stuffed up stock mufflers you’ll not only feel some seat of the pant performance but also get a better sounding exhaust. If you want even more performance gains or your future plans involve internal engine mods such as aftermarket cams, a big bore kit, or head work then you’ll want to go with a full system. And when it comes to full systems it depends on what kind of riding you do and where in the RPM range you want your performance to be. Unless the majority of your riding is spent banging around on the drag strip or gunning it from stop light to stop light then you’ll want to stay clear drag pipes. Like the name implies drag pipes are designed for bikes with built/race engines and deliver optimal results at higher RPMS.
There’s a lot of debate, especially amongst bagger owners, pitting True Duals against 2-into-1 systems. Typically, a good 2-into-1 will deliver better performance in the lower RPMs where most people will feel it most. Most true-duals aren’t too far off the performance mark of 2-into-1s, they just deliver in a different range. But then again it comes down to design pipe design and engine mods. Not all true duals or 2-into-1s are created equally so results will vary from one manufacturer to another. When it comes to baggers most owners will sacrifice the small overall performance gain of a well-designed 2-into-1 for the balanced look or true duals.
If after searching all over the place and you can’t seem to find an exhaust system that suits your needs you could always design and build your own custom pipes. A builders exhaust kit like the one offered by Biltwell comes with pretty much everything you need to fabricate your own exhaust. Complete with radiused bends, straight sections, exhaust flanges, and exhaust tips you could cut, weld, and grind to your heart’s content (or have your welder do it for you) until you have the wildest set of pipes ever mounted to a Harley. Who knows you may be the next up-and-coming exhaust designed/builder starting all the new trends.
To really ensure you get the most out of your exhaust upgrade you need to include a high-flow air cleaner and some type of fuel management device if your bike has EFI or a jet kit if you are running a carb. Your engine is a giant air box and the more air you can feed into it the more power you can create. A freer breathing air cleaner will allow more air to flow into your cylinders which will help create a larger explosion on the combustion stroke. Air filter selection can be as simple as an Arlen Ness Stage 1 Big Sucker Air Filter kit that will still fit behind your stock cover, or you can upgrade to something like Kuyrakyn’s Pro-Series Hyper Charger which comes with a new outer cover, filter, and mounting assembly all designed to improve air flow and stuff your cylinders with plenty of power potential.
Any time you make performance modifications to your bike you need to tune your bike to make sure the air/fuel ratio is in check and you are getting the most out of your new changes. If you own an older model Harley that is running a carburetor then you’ll want to look into getting a jet kit. With an assortment of jets/needles to choose from you can mix and match with larger or smaller ones as needed in order to get the right combination to get your air/fuel ratio right and your bike running in tip top shape.
For bikes with electronic fuel injection a fuel manager will allow you to tune your bike to achieve optimal air/fuel ratio and dial in the bike according to the performance modifications you’ve made by simply by installing the tuner and riding the bike or by uploading and flashing a new map into the bike’s ECM. Fuel tuners come in a variety of options with some that are simple plug-n-play units that allow you to just install the unit and then it will automatically tune and dial in your bike as you ride, like Cobra’s Fi2000R Power Pro. Other tuners have a library of maps that allow you to pick the one that matches your setup (year, make, model, engine size, cams, air cleaner, and exhaust system) and then flashes the ECM with that map so that the bike will run its best with the new components. Some tuners like the Power Vision from Dyno Jet offer a host of options like pre-programmed map downloads, auto-tuning, custom map configuration, allows you record running data, store maps, clear system codes, and operate as a diagnostic tool.
Finding the right fuel tuner device for your bike often comes down to how in-depth you want to get with your tuning capabilities and how far you intend to take the performance of your engine. If you just plan on swapping out pipes and air cleaners here and there without doing heavy internal modifications then a basic tuner will be fine. If you plan on installing a big bore kit, stroking the motor, porting and polishing the heads, and/or installing a tuned induction system, then a fuel tuner with more tuning capabilities will be a better fit for you.
So, we’ve covered a lot of ground here, but with this info you should have a better understanding of what to look for and things to consider when shopping for your next set of Harley pipes. With so many options it can be a pretty exhausting search, but then that’s part of the fun of owning a Harley—researching, shopping around, and daydreaming about how certain parts will look or perform on your bike in order to make it fit your personal style.