Unlock the full potential of your S55 with the OneFastShop 3 inch catless downpipes. The factory catalytic converters are the biggest choke point in the twin turbo exhaust - removing both frees up real power, spools the turbos sooner, and brings out the aggressive twin turbo tone the S55 was built for. Engineered for the F chassis M3, M4, M2 Competition, and M2 CS from 2015 to 2021.
Expect +25 to +40 horsepower with a supporting tune (more on big turbo builds), dramatically faster spool, and sharper throttle response. This paired set is a direct bolt-on with no cutting required, works with OEM and aftermarket cat-back exhausts, and is backed by a lifetime warranty on defects.
| Diameter | 3 inch (full diameter from each turbo outlet) |
| Material | 304 grade stainless steel |
| Turbo transition | Seamless cast v-band |
| Flanges | CNC machined |
| Welding | Hand TIG welded |
| Flex section | Integrated on both pipes |
| Configuration | Paired set (twin turbo), catalytic converters removed |
| Engine | BMW S55 twin turbo |
Engine type: This kit fits S55 equipped vehicles only. The standard F87 M2 with the N55 engine requires a different downpipe and is not compatible.
Gaskets required: Two turbo-to-downpipe gaskets are required to seal these downpipes to your factory turbos. Our 3.5 Inch Turbo to Downpipe Gasket for BMW S55 is sold separately - add two to your order.
Tuning & check engine light: Removing the cats means the rear O2 sensors will eventually set a check engine light (a catalyst efficiency code such as P0420 / P0430) on an otherwise stock car. This is normal for any catless downpipe and not a fault with the part. To run them correctly and keep the light off, the car should be tuned with the rear O2 sensors turned off - any major S55 tuning platform supports this. We strongly recommend installing these downpipes with a supporting tune rather than on a stock vehicle.
Off-road use: Intended for off-road and track use only. Not legal for use on public roads and may not comply with emissions regulations. Check local laws before installation.
| Year | Make | Model | Submodel | Engine |
|---|---|---|---|---|
| 2015-2018 | BMW | M3 | F80 (incl. Competition) | S55 |
| 2015-2020 | BMW | M4 | F82 (incl. Competition) | S55 |
| 2015-2020 | BMW | M4 | F83 Convertible (incl. Competition) | S55 |
| 2019-2020 | BMW | M2 | F87 Competition | S55 |
| 2020-2020 | BMW | M2 | F87 CS | S55 |
Shipping: In-stock orders placed before 3 PM EST ship the same day, and everything else ships within 24 hours. Standard, expedited, and overnight options are available at checkout. Backordered items ship as soon as we get them back in stock. Contact us for lead times. See the full Shipping Policy.
Returns: 30-day returns on new, unused items in original packaging. See the full Refund Policy.
