Long-Term Yamaha R1: Exhaust Dyno Test

Testing an aftermarket pipe against stock (and no muffler at all!)

R1 exhaust dyno comparison
Which is better: Stock, aftermarket, or no muffler at all? We took our R1 test bike to the Dyno room to find out.Animated GIF by Kathleen Conner

Wrist: Zack Courts
MSRP (2015): $16,490
Miles: 3,082
MPG: 33
Mods: Yoshimura slip-on

The hunt for horsepower is endless. Whether it’s the manufacturer or the consumer, everybody always wants more. With 1,000cc sportbikes the horsepower war pretty much ended when BMW debuted the S1000RR, and one of my favorite things about this R1 is that it has never pretended to be the fastest ship in the galaxy. Still, a little fiddling around on the Dyno couldn’t hurt, right?

R1 exhaust systems
Side by side by side, it’s not hard to see why the Yoshimura pipe actually weighs more—It’s bigger! The carbon fiber is slick, but the stock muffler’s size makes a big difference (and being made from Ti doesn’t hurt).©Motorcyclist

Yamaha generously supplied me with a Yoshimura slip-on muffler to try, which slides onto the exit of the catalytic converter “breadbox” slung under the R1. First thing’s first, this Yosh pipe is gorgeous. It’s carbon-fiber perfection, in the classic Yoshimura shape—nice enough to spice up any machine. Since both the stock muffler and the Yosh one were in hand, I weighed each on our shipping scale here at the office. The carbon fiber and stainless steel Yoshimura slip-on weighed in at 4.1 pounds, and the titanium muffler from the stock R1 tipped the scale at 2.2 pounds. Then we spun up the Dyno and tested, via a handful of runs, each muffler in place to see if there was a difference in power output. There was no difference. Big thumbs down for Yoshimura, right? Well, no, not really.

R1 with no muffler
Anything installed after this point in the pipe probably won’t matter much, aside from stuffing a tennis ball in there (which we also wouldn’t recommend). The R1 sounds surprisingly good with no muffler at all.©Motorcyclist

I suspected this would be the case, actually, since both the stock pipe and the Yoshimura slip-on are essentially just baffles for sound that install downstream of the very complex and high-tech breadbox underneath the engine. That massive blob of a box actually reroutes exhaust based on the speed of the engine, all the while muffling the engine and making the bike emissions compliant (see the link below for more on how the R1’s exhaust works). Just on a hunch, we did a Dyno run with no slip-on muffler (stock or Yosh) whatsoever. The result? No change. The note from the exhaust was a little raspy, but other than that there was no difference in power output.

So, bottom line: Bolt an aftermarket slip-on to your R1 if you want, but it will likely just add weight and not add power. If you want to save a couple of pounds, just remove the stock piece! The really spicy slice of the Yoshimura system is that this R1 slip-on I tested retails for $700 at shopyamaha.com (or check it out at yoshimura-rd.com). At that price it might be worth considering a full race system, which obviously isn't legal for the road and will probably make your neighbor's ears bleed. But, that's a good option if you want "pure" sound and power. Good thing I don't need the fastest ship in the galaxy.