Hyperstrada 939 slip on and tune quesriom

I just put on a carbon/carbon SC oval slip-on on my 821 and it actually seemed to improve the low end fueling slightly plus it sounds sweet with the DB killer removed. Not too loud..

With the DB killer it is almost as quiet as stock...With it removed it is not obnoxious but sounds really nice.

new streetlegal options
https://shop.exanexhaust.com/en/pro...en/hypermotard-939-2016-19-en/?v=fa868488740a

Not to be a party-pooper here, but the engine is tuned by the factory to your exhaust, they work in unison, for better or worse, to keep the engine operating within set limits in a safe manner. I'd like to think of it as a system, if one parameter changes, it affects every other part in that chain. The risk factor of installing an aftermarket exhaust without a proper tune lies with running too lean in certain rpm ranges, or maybe too rich. Most exhausts differ in how much resistance they create, this in turn also affects torque delivery. The exhaust ultimately compliments the engine by helping it run smooth, if both are on the same page.