Dinan 3.25in Stainless Steel Resonator Delete Kit - BMW F22 / F23 M235i (2014-2016)
SaleThe M235i is one of the best-balanced cars BMW built last decade. Short wheelbase, a turbo straight six and a chassis that loves to rotate. The one thing it never had was a sound to match. The factory resonator in the middle of the exhaust smooths the N55 into something too polite.
The Dinan Resonator Delete Kit for the BMW F22 M235i pulls that resonated section out and replaces it with straight-through 3.25 in. T304 stainless steel tubing. You keep the factory catalysts and rear muffler, and the car gets a more aggressive tone from the stock system. Pair it with the Dinan Free Flow Axle-Back and the sound turns into a growl that is hard to ignore.
What a Resonator Delete Does for the M235i
The factory mid-pipe uses hydro-formed 80 mm tubing with a resonator between the catalyst and the rear muffler. Dinan replaces it with 3.25 in. (82.6 mm) mandrel-bent tubing. Mandrel bending keeps the inside diameter consistent through each bend, so the gas path stays open instead of pinching at every curve. Less restriction, more volume, and a sharper exhaust note under load.
Wondering if it will be too loud? The factory rear muffler stays in place, so the change is a clear step up in volume and character, not a straight-pipe drone. It is 100% T304 stainless steel, so it will not rust out underneath the car.
Resonator Delete Fitment and Legal Status
Dinan confirms fitment with the stock exhaust and with the Dinan Free Flow Axle-Back. Fitment with other axle-back systems is not guaranteed, so check what is on your car before ordering. The resonator sits downstream of the catalysts, and Dinan classifies this part as legal for sale and use on emissions-controlled vehicles because it does not affect emissions. Dinan part number D660-0058. Sold by AutoTecknic, an authorized Dinan dealer.
What's Included
- Dinan 3.25 in. T304 stainless steel resonator delete section
- Mounting hardware
Key Features
- Deletes the factory resonator between the catalyst and rear muffler
- Replaces stock 80 mm hydro-formed piping with 3.25 in. (82.6 mm) mandrel-bent tubing
- More aggressive tone and increased volume from the stock system
- 100% T304 stainless steel construction
- Bolt-on installation with mounting hardware included
- Legal on emissions-controlled vehicles per Dinan
Vehicle Fitment
Fits the following N55-powered BMW M235i models:
- BMW 2 Series / F22 Coupe (2014-2016): M235i
- BMW 2 Series / F23 Convertible (2015-2016): M235i
Confirmed with the stock exhaust and the Dinan Free Flow Axle-Back only. Fitment with other aftermarket axle-backs is not guaranteed. Not listed for the M240i.
Installation Notes
Dinan lists 1.2 hours of labor. It is a bolt-on job, but it is a long section of pipe, so a lift or a second set of hands makes it much easier.
- Let the exhaust cool completely, then safely raise and support the car.
- Loosen the clamps on either side of the factory resonator section.
- Unhook the factory section from its hangers and remove it.
- Fit the Dinan resonator delete section and install the supplied mounting hardware loosely.
- Align the system, tighten all clamps, then start the car and check for leaks and body contact.
