Dinan Free Flow Axle-Back Exhaust - 2020-2025 BMW X3M/X4M

OVERVIEW

The "baby M's" of the X family finally get a big-brother voice. Dinan's Free Flow Axle-Back replaces the restrictive factory rear section on the F97 X3M and F98 X4M (S58) with a valved, straight-through system that delivers a deeper, fuller, more menacing tone — with civility on demand. Larger 76mm tubing (vs 70mm stock) frees flow through both outer pipes when the enlarged, computer-controlled valves are open; when closed, gases route through the muffler and exit the two inner tips for quiet cruising. Drone-abatement technology inside the can keeps the cabin conversation-friendly regardless of valve position.

SPECS

• 76mm mandrel-bent T304 stainless steel tubing (vs 70mm stock)
• Twin 76mm exhaust valves, ~30% less restrictive than OE
• Retains factory computer-controlled valve operation
• Verified gains: +8 HP and +6 lb-ft of torque at 6600 RPM
• Quad 114mm (4.5") tips
• Drone-abatement muffler for low-drone cruising
• Finish: polished stainless or black ceramic-coated tips

PARTS INCLUDED

• Dinan valved axle-back exhaust section
• Mounting hardware

TECH RESOURCES

• Installation Instructions (PDF)
• Pair with the Dinan Dual Exhaust Valve Remote (R660-0002) for one-touch valve control

PART NUMBER

• Polished — D660-0086
• Black Ceramic Coated — D660-0086-BLK

VEHICLE APPLICATIONS