Akrapovic KTM Pipe

When you buy an Akrapovic exhaust system, you buy a very nice piece of work. And for the cost, they have to be. The header runs $789.99 thanks to the material, high-end machine work and bottomed-out exchange rate between the dollar and the Euro. The featherlight and appropriately quiet Ti/carbon muffler/spark arrestor is $724.99. There, we got the hard part out of the way. Now on to the fun part!

The Akro is titanium and carbon fiber with three parts, and springs at all the joints (these joints are marvelously tight and precise). The only hitch to the install is a required removal of the shock to get the mid-pipe in and out. KTM shocks take about three minutes to remove. We tested the system on both a mellow, smooth and tractable KTM 400 XC-W and the more popular and muscular 450 XC-W.

Typically the 400 is easier to ride in the woods, since the power makes it a little easier to maneuver technical trails on than with a typical 450. The trade-off is that it sometimes lacks the snap you need to easily wheelie over an obstacle. I found the Akrapovic system made a substantial improvement on the 400, and much more than I usually expect from an exhaust system-even a high-end unit with a humbling price tag.

The best effect was extra snap way down in the powerband thanks mostly to the header with its approximately 2mm smaller manifold and I.D. I suspected that the header's benefit was the biggest difference over stock, and it does provide the boost in the lower half of the powerband, but the muffler-even with the stock header-lets the bike sing on top. The bike requires far less clutch to get moving out of uphill turns, and wheelies are much, much easier to generate at will without snatching your shoulders out of joint. The performance increase even made the bike responsive enough to be fun on the motocross track, and I never thought I would say that about the 400. The pipe also kept the incredibly wide power spread that I love about this bike. The system is lighter than stock and responsibly quiet at 92 decibels, though it sounds a bit louder at full-throttle than the stock muffler that passes the static sound test at 96 decibels.

On the 450 the power gains were equally impressive. The bike has a lot more energy everywhere yet makes major boost up top and accelerates much harder. The header makes a difference, but since the 450 already has enough bottom power I'd recommend the muffler first on the 450, then see if you want to upgrade to the full sweetness version. The only drawback is that it is not cheap, but that is what it takes to make something better and quieter than the stock KTM exhaust system.

Akro pipes for KTM four-strokes are only available from your KTM dealer in the U.S. -Karel Kramer