GP-Magnum Slip-On. 2024 - 25 Triumph Scrambler 400 / 2024 - 25 Triumph Street: A 398cc retro water cooled Triumph? Yes please! For some time now, Yoshimura has been waiting to get their hands on the Scrambler / Speed 400 and they are so thrilled to have an offering now. The GP Magnum slip-on looks just perfect on the Scrambler / Speed 400. A weight savings of as much as 3 pounds is one thing, but the performance is another with a 2.08% increase of HP at 8000 RPM and a 3.8% increase in torque at 6,300 RPM just nails it. The GP Magnum comes out of the box with a sound insert, but it can be easily removed for a more aggressive tone. Note: Emissions Compliance Declaration: Qualified manufacturer declared "replacement part." Now the Triumph Scrambler / Speed 400 sounds proper!