A properly chosen exhaust, SPP’s Jason Hanson explained, is important. “A motor’s got to breathe,” he says. And to a large degree the exhaust system can dictate the amount of torque made and the characteristics of that power, the length of time throughout the rpm range the engine will be producing its maximum torque. And as so dramatically shown on that 150 foot-pound bruiser the ultimate exhaust solution for horsepower and torque is a quality 2-into-1, a system with equal-length header pipes or as close to equal as you can get. Installing that power-building 2-into-1 on a bagger bike, like Jason did with that mega-motor CVO, it’s no problem, either, visually speaking. A non-functional “ghost” muffler and pipe mounted over on the left side balances the look.
Does this mean anything less than a 2-into-1 is a step in the wrong direction? Absolutely not, the SPP techs say. Properly chosen Staggered Duals and True Duals can both be extremely efficient street systems, especially on more mildly tuned bikes. For best performance, though, the Speed’s team highly recommends a dual system incorporating some sort of crossover connection between the head pipes, a design giving that dual-system some of the scavenging characteristics of a 2-into-1. Kuryakyn’s Power Cell X-Pipe and the S&S Power Tune Duals are two good examples. And Harley’s factory-connected dual exhausts can get a nice little performance boost, too, when set up with the right set slip-ons. The S&S decibel-compliant Performance Mufflers, for example, are a nice choice for anyone looking for a quiet-running bike with a bit of a performance boost. Even that system can become pretty efficient up to about 4,000 rpm or thereabouts.
Obviously there are a plenty of variables at play here, but for the average street-ridden V-twin, a bike with minor modifications like a free-flowing air filter and a performance tune-up, for instance, a carefully chosen upgrade exhaust will significantly boost horsepower and torque. And as the guys at Speed’s note, all other things being equal that 2-into-1 system with equal-length headers will perform best. Hands down. “But to tell the truth,” Jason says, “on the dyno and out on the street we’re getting darn near the same level of performance out of some of those connected true-duals. They won’t match the power and torque of a 2-into-1 exactly, but they come pretty close. It’s just one small step down.”
Increased power and crisper throttle response isn’t the only benefit a performance exhaust has to offer. That free-flowing system can remove lots more heat from the engine, good for both it and for the comfort of the rider and passenger. Newer-model bikes, especially, tend to run hot, but with the switch to a more efficient exhaust system things can cool down significantly. That’s something any rider, and passenger especially, will appreciate. Bagger passengers love it when that crossover pipe is running underneath the motorcycle, further removing the heat source. A welcome move on the factory’s part, riders and passengers on the earlier model bikes, the 1999 –2006 FLs, can get that same under-the-bike exhaust too. There are connected true-dual pipes available that convert those early-style exhaust crossovers to the newer under-the-bike configuration, systems such as the S&S Power Tune Duals. “And trust us,” Jason says, “that swap alone makes things a lot more comfortable heat-wise.”
New pipes are tops on most riders’ wish lists. They can look better, sound better, and, when they’re chosen correctly, work better. It’s that last bit, though, that can get tricky. An exhaust system is about more than shiny chrome and a deep rumble. It’s about how a bike performs, about how and where it makes its power, and about how it responds to the throttle. And not insignificantly, it’s also about how comfortable it is in the saddle, heat-wise, for both rider and passenger. Stop in and talk with the guys at Speed’s Performance Plus next time they’re at a local event. Take a look at all this for yourself; the full tour schedule is on the website.
(605) 695-1401 — MN
(605) 695-2272 — SD