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Evolution Racewerks Competition catless downpipe for BMW N55 X5 X6 (F15 / F16)
EVOLUTION RACEWERKS

Evolution Racewerks Competition Series 4" Catless Downpipe — N55 (X5 / X6)

$765.00

Evolution Racewerks Competition Series 4" catless downpipe for the single-turbo N55 in the X5 35i and X6 35i (F15/F16). Replaces the factory downpipe and catalytic converter — the post-turbo restriction that caps a tuned N55 — with a mandrel-bent 4" stainless pipe.

Why a downpipe on the N55

The factory downpipe is built around the cat for emissions, and at Stage 2 boost it becomes the limiting factor on spool and top-end. Opening it to a full 4" lets an Esse Werks calibration use the turbo's real airflow ceiling.

What Evolution Racewerks builds in

  • Mandrel-bent 4" piping (expanded from the factory 3.5" turbo outlet), 100% T304 stainless
  • CNC-machined billet 304 stainless V-band turbo flange (factory 3.5" V-band)
  • 100% stainless-steel flex section for driveline movement
  • 100% TIG-welded; made in the USA at Evolution Racewerks' California facility

Finishes

Brush, Polish, or our signature SwainTech White Lightning ceramic coating — choose above.

SwainTech White Lightning — our signature coating

When we coat a part, we use one coating: SwainTech White Lightning — a true ceramic thermal barrier applied about 0.015" thick (versus roughly 0.002" for paint-style "ceramic" finishes) and sprayed molten so it bonds to the metal instead of sitting on top. It cuts radiant heat off the exhaust by roughly 35–55%, dropping underhood and intake temperatures, and keeps heat inside the pipe where it sustains exhaust velocity and scavenging. And it's white — a deliberate signature in a market that otherwise all looks the same in black. Select it above.

California restriction

Race/competition part. Not for sale, installation, or use on pollution-controlled vehicles in California — 49-state product; Vehicle Compliance Waiver signed at order intake. International orders ship without restriction.

Fitment

BMW N55 — X5 35i and X6 35i (F15/F16). Confirm your chassis in the selector.

This part is the downpipe-side core of every N55 Stage 2 build. The Stage 2 Kit — N55 packages the matched parts + calibration for 8% under à la carte.

Fits engine N55
Fits chassis F15 · F16
Category Exhaust
Manufacturer Evolution Racewerks
What this is

A Part Recalibration is one focused revision built around the part you just bought. We take logs on your car as it runs now, on your current tune, then make a single full revision so this specific part delivers what it should. Hardware only does its job with a calibration shaped around it.

We bundle that tuning with the part right here, whatever brand the hardware is. If you want a fresh start across all your hardware, a Full Tune is the step up: a new base map, three revisions, and a written report.

This is a bootmod3 calibration. We tune through your own active BM3 license, so you'll need bootmod3 active on your car to load it.

Ships freight from Boca Raton, FL — additional fees may apply at checkout.

Step up to a Full Tune?

You've added a Part Recalibration to more than one part. At that point a complete tune does more for you: a Full Tune lays down a fresh base map and three revisions so all of your new hardware is dialed in together, with a written report at the end. We can roll your recalibrations into one Full Tune for $395 — below our standalone Full Tune, which starts at $495 for a four-cylinder and $595 for a six.

The Full Tune is a bootmod3 calibration — it loads through your active BM3 license, the same one you confirmed for the recalibration.
WHY WE SHIP EVOLUTION RACEWERKS
Cooling is the first thing to run out on a boosted BMW, and Evolution Racewerks builds the charge coolers and intercoolers that buy back the headroom. The bar-and-plate cores carry more thermal mass than the factory units, which is what keeps intake temps from climbing into timing-pull territory on a back-to-back pull. Their charge pipes also delete the factory plastic coupler that is a known weak point under boost. When a Stage 1 or Stage 2 car is heat-soaking on the second hard pull, a competition cooler from Evolution Racewerks is usually the fix that holds the tune's numbers session after session.