Here's What Swapping To A 2-Into-1 Exhaust Can Do For Harley-Davidson Performance

Harley-Davidson motorcycles are a joy to ride right off the bat, but swapping the stock mufflers for a 2-into-1 exhaust is an incredible mod that can generate noticeable performance enhancements. Your Harley's exhaust is not just about sound, since a high-quality exhaust kit will significantly impact the style, throttle response, and acceleration of your ride. That's precisely why you should consider a 2-into-1 exhaust if performance-enhancing mods are your thing.

The kit typically consists of two head tubes that connect to each cylinder and merge into a single tube on the exhaust end, hence the name '2-into-1.' There are cheap mods that could potentially make your Harley ride better or look cooler, but a complete exhaust upgrade isn't the most affordable option; a Sawicki Speed 2-into-1 Harley exhaust kit starts at around $1,250, for example. Still, there's no denying that a 2-into-1 exhaust can unleash some incredible power and sound, and that's thanks to how it optimizes the exhaust velocity – in other words, how quickly the spent gases leave the combustion chamber.

Perhaps the most definitive merits of upgrading from a stock exhaust are enhancements to the flow and scavenging of the exhaust. Although many factors play a part in improving the exhaust flow (like the tube diameter, for instance), the less restrictive design of a 2-in-1 allows hot gases to expel faster from the engine. This improves exhaust scavenging, helping the engine pull more air/fuel and produce more horsepower. A 2-into-1 exhaust also significantly reduces backpressure thanks to the increased flow, which helps keep the engine output strong at higher revs. 

Other benefits include less weight, a compact design, a more potent exhaust note, better fuel economy, and tuning compatibilities with other mods like ECM remapping and aftermarket air filters. The downsides are few, but they're still worth mentioning. Besides the cost, although 2-into-1 exhaust systems work great at low-to-mid rpm, they may strangle engine performance at higher rpm. Furthermore, upgrading to a 2-into-1 exhaust may require an engine tune depending on the application.

A 2-into-1 exhaust starts with two exhaust tubes and ends with a single pipe. Meanwhile, a 2-into-2 refers to a genuine dual pipe design, with two pipes from the engine and two exhaust tips at the back. The 2-into-1 provides a sportier vibe, while a 2-into-2 exhaust is for Harley riders who cherish the classic design of vintage bikes.

In terms of sound, a 2-into-2 exhaust system lends a more refined and balanced exhaust note without losing that characteristic Harley V-twin rumble (which our readers pointed out as one of the most recognizable exhaust notes from anything with wheels). In addition, a genuine dual pipe design is generally more ideal for high rpm applications, and they're more comfortable for touring or extended rides.

The "better" style ultimately depends on what you want in an aftermarket exhaust system. A 2-into-1 will unlock more horses at low-to-mid revs while giving a more powerful sound. On the other hand, a 2-into-2 lends a throwback vibe, is comfier on long-distance cruises, and performs better at higher revs.

After quickening the flow and improving the exhaust scavenging with a 2-into-1 exhaust kit, unlocking more performance is possible with a high-flow air filter – particularly from Harley-Davidson's Screaming Eagle K&N air filter lineup. Like most K&N air filters for cars (which are washable, last longer, and can unleash more power, making them a bang-for-your-buck upgrade), a higher-flow air filter allows more air to pass through your bike without sacrificing filtration. Potentially, this adds horsepower and delivers quicker acceleration.

Next in line is a Harley fuel tuner, which is an excellent add-on after upgrading the air filter and installing a 2-in1 exhaust kit. A flash tuner can maximize the power, top speed, or fuel economy of your Harley, as well as the potential of aftermarket mods. Finally, a quick-shifter kit is worth considering if speed is at the top of your agenda. A quick-shifter is an upgrade that enables lightning-speed upshifts (or downshifts) by simply pressing a button. With its help, you won't need to mess with the clutch or put excess stress on your transmission.