Downpipe Installation B46 / B48 / B58

Downpipe Installation for BMW (B46 / B48 / B58 Engines)

This product covers professional downpipe installation only for BMW vehicles equipped with longitudinally mounted B-series engines: B46, B48, and B58.

The downpipe hardware itself is not included.

You choose the downpipe that fits your goals — performance or sound — and we handle the installation at your location.

How a Downpipe Increases Power

The factory downpipe is one of the most restrictive components in the turbo exhaust system. By upgrading to a high-flow downpipe, exhaust gases exit the turbo more efficiently, which allows: 

✔ Faster turbo spool

✔ Lower exhaust backpressure

✔ Reduced exhaust gas temperatures

When combined with proper ECU tuning, this typically results in:

•  +25–30 horsepower

•  Increased torque

•  Sharper throttle response

Tuning is required to achieve power gains. A downpipe alone improves flow, but tuning unlocks the full performance benefit.

Why a Downpipe Is Required for Stage 2 Tuning

For most Stage 2 and higher BMW tunes, a downpipe is mandatory.

It enables:

• Safe operation at higher boost levels

• Consistent power delivery

• Reduced thermal stress on the engine

Running aggressive tuning on a stock downpipe can limit performance and increase heat.

Downpipe Options (Customer Supplied)

We install any downpipe of your choice, including:

• Catted downpipe (high-flow catalytic converter)

• Race downpipe

You choose the brand and configuration — we install it professionally.

Supported Engines

✔ B46

✔ B48 (longitudinal layout)

✔ B58

This service is for rear-wheel-drive or AWD BMW platforms with longitudinally mounted engines

Not compatible with transverse-mounted B48 vehicles

Supported BMW Models (Typical Applications)

B46 / B48:

• BMW 330i / 330xi (G20)

• BMW 430i / 430xi (G22)

• BMW 530i (G30)

• BMW 630i (G32)

• BMW X3 30i (G01)

• BMW X4 30i (G02)

B58:

• BMW 340i / 340xi (F30 / G20)

• BMW 440i / 440xi (F32 / G22)

• BMW 540i (G30)

• BMW 640i (G32)

• BMW 740i (G11 / G12)

• BMW X3 M40i (G01)

• BMW X4 M40i (G02)

• BMW X5 40i (G05)

• BMW X6 40i (G06)

Production years typically range from 2016–2019+, depending on model and engine variant.

If you are unsure about your engine or fitment, contact us before purchasing.

What’s Included

✔ Mobile downpipe installation

✔ Removal of factory downpipe

✔ Installation of customer-supplied downpipe

✔ Fitment and hardware check

*downpipe hardware not included

*ECU tuning not included

Important Notes

• Price is labor only

• Power gains depend on tuning and setup

•  Emissions compliance depends on downpipe choice

•  Off-road / race use may apply depending on configuration

!  We do not install, modify, or remove emissions control devices, including catalytic converters. Requests for catless downpipe installations or other emissions-delete modifications will be declined