Full System Exhaust Turns The Ninja 650 Into A Monster 

Whats the best exhaust to install without tuning? I have a 2022 ninja 650

which one is the less loudest between the yoshimura/leovince and two borthers ? please :)

There's just way too much data from professional tuners on RU-vid to have you remain ignorant about how fuel injection, modern bikes, and ECU's work. Anyone who runs a full system without a tune is leaving most of the power on the table, and leaving an engine that runs less optimal. It varies from model to model but none are fueled properly and ECU's on bikes are nowhere near as sophisticated nor the same type as what is on vehicles. They don't run the same O2 sensors, don't have the same fuel maps, don't compensate for big air-flow changes. I've never understood the desire to install a system costing 800-1200 dollars and not spend 250 to make the most significant change in the entire process.