The BMW N55 is the single-turbo 3.0L inline-six that succeeded the N54, and it powered a huge range of cars — the 135i, 335i, 435i, M235i, and the base F87 M2. It uses one twin-scroll turbo instead of the N54's two, which makes it simpler, more reliable, and quicker to spool. It responds beautifully to bolt-ons and is one of the best-value tuning platforms BMW ever built. This guide lays out a proven stage-by-stage path and the parts we stock for each step.
Every link below goes to the matching Speed Logic collection so you can check current fitment and pricing for your exact car.
Know Your N55 Car
In the US, the N55 (roughly 2011–2018) appeared in the 135i (E82/E88), 335i (E90/E92/E93 and F30/F31/F34), 435i (F32/F33/F36), M235i (F22/F23), 535i (F10), the base F87 M2, and various X-models. It is the simpler, single-turbo sibling of the N54: one twin-scroll turbo, direct injection, and strong reliability. Note that the 340i and 440i that replaced the 335i and 435i use the B58, not the N55. Likewise, the base F87 M2 uses the N55, while the M2 Competition and CS use the S55 — a detail worth confirming before you buy fitment-specific parts.
The N55 Stage Build Path at a Glance
| Stage | What you add | What it needs | Typical goal |
|---|---|---|---|
| Stage 1 | Tune (flash or piggyback) | Good fuel, healthy engine | Biggest gain per dollar |
| Stage 2 | Downpipe + intake + charge pipe | Stage 2 tune to match | More flow, quicker spool |
| Stage 2+ | Upgraded intercooler + cooling | Consistent intake temps | Hold power on repeat pulls |
| Stage 3 | Fueling (port injection) + ethanol | Flex-fuel capable tune | Support higher boost safely |
| Big power | Upgraded / hybrid turbo | Full fuel, cooling, clutch | 450+ whp territory |
Stage 1 — The Tune (Start Here)
As on every turbo BMW, the tune is the best value on the N55. A recalibration alone delivers a large jump in power and torque and sharpens throttle response. You can flash the DME with MHD Flasher or run a reversible JB4 piggyback — both are popular on the N55, and our tune comparison guide breaks down the differences. Because the N55 uses a single turbo, gains are very consistent and easy to live with.
Stage 1 just needs good fuel and a healthy car. Browse options in the N55 Tuning collection.
Stage 2 — Free up the Airflow
Once the tune is proven, add airflow:
- Downpipe. A high-flow catted or catless downpipe frees exhaust flow and improves spool. See the N55 Exhaust collection and our full Exhaust & Downpipes collection. New to catted vs catless? Read our downpipe explainer first.
- Charge pipe. The factory plastic charge pipe is a known failure point under boost — an aluminum N55 charge pipe is cheap insurance and improves throttle response.
- Intake. A performance N55 intake feeds more air and adds sound.
Update to a Stage 2 tune any time you change airflow hardware so the calibration matches.
Stage 2+ — Cooling Holds the Power
The N55 makes strong, consistent power but benefits from an intercooler upgrade to keep intake temps down on repeat runs and hot days, so the tune can hold timing and boost. Shop N55 Intercoolers and broader N55 Cooling parts.
Stage 3 — Fueling for Ethanol and More Boost
Like other DI BMW turbo motors, the N55's factory fuel system becomes the limit at higher power, especially on ethanol. Adding port injection or fueling upgrades gives the tune headroom and unlocks flex-fuel. See the N55 Fueling collection.
Going for Big Power
The N55's single turbo is the main airflow ceiling, so serious power comes from an upgraded or hybrid turbo backed by full fueling and cooling. We stock turbo options in the N55 Turbo Kits collection. At that level the clutch and drivetrain enter the picture too — talk to us so we can spec a package that works together.
Don't Forget the Chassis
Once the engine is sorted, suspension transforms how the car drives. We stock KW, H&R, and Bilstein — from a simple lowering-spring drop to full coilovers. See what fits in the N55 Suspension collection, and read our coilover buying guide to pick the right setup.
Recommended First Three Purchases
- 1. Tune — MHD or JB4. Biggest single gain.
- 2. Charge pipe — cheap, prevents a common failure, improves response.
- 3. Downpipe + Stage 2 tune — the airflow upgrade that unlocks the next level.
Then cooling, then fueling if you plan to push further. Build in stages, tune to match, and the N55 delivers strong, reliable, repeatable power.
Start your build in the N55 Engine collection, or shop the base F87 M2 (N55) collection. Need a hand speccing it? We are here to help.
Many parts described here — downpipes, tunes, and turbo upgrades — are intended for closed-course competition or off-road use and may not be legal for use on pollution-controlled vehicles on public roads. Check your local and state emissions regulations before purchase. Power figures vary with fuel, supporting modifications, and tuning; ranges are typical and not guaranteed. Always confirm fitment for your exact chassis, engine, and year.