The above Dyno chart shows gains over the stock numbers in Red to the improved numbers in Blue. This was a 100% stock 2017 M8 Roadglide with just over 1000mi on the odometer. The only parts changes were the Slipon Mufflers, which were changed to the SVT Boneshakers, NO other changes or modifications were done. Please note...the gains are "peak" numbers, If you notice the gains between 3000 rpms and 3500 rpms the gains are nearly doubled from 2hp/4tq to 4hp/8tq. This is a simple bolt on set of mufflers that made these gains in Hp/Tq. All Dyno records are stored at Dothan Harley Davidson in Dothan, Alabama and are documented as accurate.
The above Dyno chart was done on the same 2017 M8 after a full Stage One Kit was installed. A 2 into 1 Conversion Header was installed with an SVT Boneshaker Slipon Muffler, A Thundermax EFI System was installed, along with an S&S Stealth Breather. NO other changes were made. Notice the Blue line shows the 100% stock numbers, and the Red line shows the numbers after the Stage One Kit was installed. Gains of 9.4tq and 10.7hp can be seen. Again these are "peak" numbers, notice again between 3000rpms and 3500rpms close to 15 point gains can be seen. This is a significant gain in both Hp/Tq in that power range, which is right where its needed. All Dyno records are stored at Dothan Harley Davidson in Dothan, Alabama and are documented as accurate.