Diamondback 2-into-1 Exhaust Systems / '17-'23 M8 Motors

The S&S Diamondback 2-into-1 is an all stainless exhaust for '17-'23 M8 Touring models, with a 4" muffler that ends ahead of the rear axle.

Ending the muffler before the rear axle is the design decision that defines this system. It changes the profile of the bike substantially, and it moves mass forward, but it also means the collector and muffler have to do their work in less space. S&S used oversized stepped primary tubes and a calculated header length to make that work rather than simply shortening a longer system.

How the Diamondback System Performs

Oversized stepped header primary tubes handle flow, with header length calculated to build power across the range rather than at one point. Computer aided design and precision bending buy improved ground clearance, which pairs with the shorter muffler for a more aggressive stance. Four exhaust bungs make O2 sensor installation straightforward for anyone monitoring air fuel ratio. Everything is stainless, including the header pipe heat shields. Made in the USA.

Diamondback 2-into-1 Specifications

• Fits '17-'23 FLHT, FLHTK, FLTRK, FLTRU, FLHR and FLHX models
• Full stainless steel construction including header pipe heat shields
• Oversized stepped header primary tubes
• 4" OD stainless steel muffler ending before the rear axle
• Four exhaust bungs for O2 sensor installation
• Improved ground clearance from computer aided design
• Versions: 50 state legal, or race only
• Finishes: stainless steel or Guardian Black
• Made in the USA

Choosing Between the Two Versions

S&S lists one version as 50 state legal. Purchasing the race only product requires filling out a form acknowledging that it is not legal for road use. ⚠️ VERIFY current emissions status and street legality for your state and model year before purchase.

⚠️ VERIFY street legality and emissions compliance for your state and model year before purchase. Most aftermarket performance exhaust systems are intended for closed course competition use and are not certified for street use in all jurisdictions. Plan on retuning the bike after installation.