Back in the era of my misspent youth, things used to be so much simpler. You’d take your new motorcycle home, bolt-on a “Closed Course Only” aftermarket exhaust, and (if you were smart) install a jet kit in the carburetors. The result was significant power gains and weight loss. Today, things are a little more complicated. Carburetor jet kits are illegal in some states, and the OEMs are making it tougher for EFI piggyback systems to alter what the EPA dictates your air/fuel tuning should be. Additionally, it is much more difficult to get aftermarket exhausts in some places.
While exhaust manufacturers have responded by building EPA-legal slip-ons that meet noise restrictions, the result is the limiting of easy power gains. My experience with the Akropovič “Slip-On Line” ($860) from the KTM PowerParts catalog highlights this challenge. After the slip-on was bolted in place, a trip to the dyno revealed the sad news: a 0.8 peak horsepower loss. While the muffler, IMO, looked and sounded better (not to mention the 2.1 lb. weight savings), some MOrons mocked me for my folly. At that moment, I vowed to increase the power output of my KTM 790 Duke.
Because I was out of my league with this challenge, I reached out to KTM guru and head honcho at Rottweiler Performance, Chris Parker, to see if he could help me with my challenge. While on the scale of products/services that Rottweiler provides, my request is relatively small. After all, Rottweiler builds adventure bikes capable of finishing fourth in the six-day Sonora Rally Against purebred race bikes. My requirements were simple: no excess noise (i.e. I was keeping my slip-on legal), no reduction in streetable rideability, and no Check Engine light (a common side effect of circumventing an EFI system’s …read more