Akrapovič Evolution series exhaust lineage can be traced directly back to the Slovenian company’s race pipes, which have been mounted on world championship-winning bikes since 2000.
We tested this high-end system—available for 2009 to 2017 Kawasaki ZX-6R sportbikes in 600cc and 636cc configurations—on a near-new 2009 model. It features a titanium 4-2-1 header, a hexagonal carbon-fiber muffler and some of the world’s most beautiful welds in between. Swoopy collector pipes sculpted from .9mm thin titanium sheets and formed with ultra-high water pressure, mate with the cylinders’ exhaust outlets on supplied flanges. When assembled, this beautiful quartet weighs 1-1/2 pounds less than the 2009’s stock titanium header. Each of the Akro system’s slip-fit pieces are firmly held together with lightweight high-tension springs.
Moving further, a short link pipe accepts the Kawi’s existing exhaust-gas sensor. Out back, the muffler is wrapped in carbon fiber made in-house by Akrapovič; it’s 19 inches long, has a 31-inch outer diameter and weighs just 3.1 pounds. The can is held in place by an exquisite carbon-fiber clamp.
Akrapovic says that its carbon-fiber end cap’s menacing 70mm x 48mm outlet delivers a healthy, 99-decibel bark at 6,750 rpm that can be mellowed with a slip-in baffle that spits through a 34mm wide hole to reduce the noise by 6 decibels.
The ZX-6R’s entire stock system scales in at 21.5 pounds. At just 8.7 pounds, the entire Akrapovič pipe, and hardware weigh less just than the ZX-6R’s hulking muffler alone. This 12.8-pound overall difference brings the Ninja’s 421-pound. wet weight down to 408, giving the Akro-equipped bike a three-percent drop in overall weight.
Installation entails removing the Kawi’s seat, side panels, lowers and disconnecting its exhaust valve. Mounting was glitch-free with detailed instructions illustrated by 41 photos.
Simply bolting on the non-baffled exhaust system netted six percent more peak power. Our independent results nearly mirror the company’s claimed seven-percent bump in maximum horsepower. Miraculously, even with the quiet baffle installed, the ZX-6s’s power curve and numbers are nearly identical; losing just 1/3 of a tick near redline in quiet form.
Like many frontline sportbikes, the Zixxer’s stock fueling isn’t perfect. To optimize fuel management, a Bazzaz Z-AFM fuel controller (Bazzaz.net, $350) was installed. Its finely honed, as-delivered mapping injected more juice throughout the Kawi’s rev range, giving it another 3.1 percent more horsepower at peak. Together, these bolt-on and plug-in mods netted 9.22 ponies, a full 9.1 percent over stock.
That’s all well and good, but what about the EVO’s $2,200+ price tag? Studying Akrapovič’s published power and weight numbers, we found that its performance is identical to that of Akro’s Racing series full exhaust, which substitutes stainless-steel headpipes for the EVO’s titanium beauties. The cost: $629 less and 2.6 pounds more.
The chart below shows Akrapovič's claimed dollar-per-horsepower and dollar-per-pound calculations across its trio of offerings for Kawasaki’s World Supersport-winning middleweight.
|TORQUE INCREASE||4.5 lb-ft||4.5 lb-ft||1.2 lb-ft|
|WEIGHT SAVED OVER STOCK||16.5 lbs.||13.9 lbs.||5.5 lbs.|
|$ PER HP||286||205||328|
|$ PER POUND||135||115||143|
Akrapovič Evolution Full Exhaust
MC Grade: A-
Summary: This high-end, titanium work of art boosts ZX-6R muscle by 6 percent and weighs 13 pounds less than the stock system. It scores major bonus points for a -6 dB sound-muffling baffle that doesn’t sap horsepower, but picks up some demerit points for its titanium headers’ $629 premium over the Race system’s stainless-steel pipes.