Dinan Free Flow Axle-Back Exhaust with Polished Tips - BMW F80 M3 (2015-2018) / F82 / F83 M4 (2015-2020)

The S55 in your F80 M3 or F82 M4 has a great voice. The factory mufflers just keep it on a short leash. The Dinan Free Flow Axle-Back Exhaust lets it out, with a sharper, more aggressive note under acceleration and less drone when you're cruising.Dinan builds it from 100% T304 stainless steel and finishes it with four 3.5 inch laser engraved polished tips. It reuses your factory valve actuators, so the M Drive exhaust settings work the way they did from the factory: civil when you want it, wide open when you ask for it.How the Dinan F80 M3 / F82 M4 Axle-Back Exhaust WorksComputer controlled valves limit noise during low speed driving and open fully under high load. Dinan's twin secondary valves measure 76mm, which Dinan rates at 45% less restrictive than the factory valves. Drone abatement keeps cabin resonance down on long drives, and the system weighs 3 lbs less than stock. Dinan rates the gain at +5 hp.Polished or Black TipsThis listing is the polished stainless tip version. If you'd rather have a stealthier look, the same system is available with black ceramic tips.What's Included Dinan Free Flow axle-back exhaust system with four 3.5 inch polished tips Clamps Hangers Key Features 100% T304 stainless steel construction Quad 3.5 inch laser engraved polished tips Factory valve actuators reused, M Drive exhaust settings retained Twin 76mm secondary valves, 45% less restrictive than the factory valves (Dinan rating) Drone abatement for a quieter cabin at cruise 3 lbs lighter than the factory system Uses the factory brackets, hangers and mounting points Specifications Brand: Dinan Part Number: D660-0050 Product Type: Axle-back exhaust Material: T304 stainless steel Tips: Four 3.5 inch, polished, laser engraved Power Gain: +5 hp (Dinan rating) Weight Savings: 3 lbs vs stock Emissions: 50-state legal, does not affect vehicle emissions Labor Time: 1.8 hours (Dinan estimate) Chassis: F80 M3, F82 M4, F83 M4 Engine: S55 Vehicle FitmentConfirmed fitment for the following vehicles: BMW F80 M3 Sedan (2015-2018) BMW F82 M4 Coupe (2015-2020), including M4 CS (2019-2020) and M4 GTS (2016) BMW F83 M4 Convertible (2015-2020) Not for the G80 M3 or G82 M4.Emissions and LegalityDinan classifies this axle-back as legal for sale and use on emissions controlled vehicles in all 50 states because it does not affect vehicle emissions.Installation NotesDinan estimates 1.8 hours of labor. The system hangs on the factory hangers and mounting points and reuses your factory valve actuators. A lift makes the job much easier, and Dinan's installation instructions cover every step. Let the exhaust cool completely and raise the car on a lift or secure jack stands. Unplug the factory valve actuators and remove the factory rear mufflers as described in Dinan's instructions. Hang the Dinan system on the factory hangers and reinstall the factory valve actuators. Align the tips in the rear valance, tighten all clamps and check for leaks and clearance. Confirm the valves respond to your M Drive exhaust setting before driving.