High-Flow Heat Shielded Catless Downpipe (BMW B48)

RPM Tuning 304 Stainless Steel High-Flow Heat Shielded Catless Downpipe – BMW (G20 & G30)

Unleash Pure Performance with Precision Craftsmanship.

(Replaces OE Part No. 18329797597)

Upgrade your BMW 2.0L and experience the true potential of the B48 engine with the RPM Tuning 304 Stainless Steel High-Flow Heat Shielded Catless Downpipe. Engineered for enthusiasts who demand uncompromising power, durability, and quality, this downpipe is your gateway to serious performance gains.

Sizing:

4.0 Inch turbo Side
3.0 Inch Exhaust Side

✅ Premium Build Quality & Materials

✅ Top Quality 304 Stainless Steel

• Superior strength and corrosion resistance

• Built to withstand high exhaust temperatures and harsh conditions without fatigue or cracking

✅ Precision TIG Welding

• Each downpipe is TIG-welded by skilled craftsmen

• Ensures precise welds, smooth internal transitions, and an immaculate finish

• Maximizes durability and eliminates weak points that can fail under thermal stress

✅ Perfect OEM Fitment

• Direct bolt-on replacement for the factory downpipe

• Designed for seamless integration with both stock and aftermarket exhaust systems

✅ High-Flow Catless Performance

• Removes restrictive factory catalytic converter for dramatically improved exhaust flow

• Reduces backpressure, allowing your turbo to spool faster and deliver more power

• Supports higher boost levels and advanced ECU tuning

• Significant increases in horsepower and torque — a must-have for Stage 1 and Stage 2 builds

✅ Integrated Heat Shield – Critical Thermal Protection

Heat management is crucial in modern turbocharged engines. That’s why the RPM Tuning downpipe features a professionally integrated thermal heat shield, delivering key advantages:

• Keeps extreme exhaust heat contained inside the pipe rather than radiating into the engine bay

• Protects vital components like wiring harnesses, sensors, and intake parts from heat damage

• Helps maintain lower Exhaust Gas Temperatures (EGTs), safeguarding your turbocharger and engine internals, especially during spirited driving or track sessions

• Enhances performance consistency under demanding conditions

Without effective heat shielding, heat soak can rob your BMW of power and reliability. Our integrated solution ensures you stay cool — and fast.

✅ Aggressive Exhaust Note

• Adds a deep, sporty tone that truly lets the B48 engine’s character shine

• More presence without excessive cabin drone

✅ Lifetime Warranty for Confidence

At RPM Tuning, we back our craftsmanship with confidence. All our downpipes are covered by a Lifetime Warranty, underscoring our commitment to quality, performance, and durability.

✅ Compatibility For Following Models:

3 Series G20 Sedan (10/2017 — 06/2022)
3 Series G20 Sedan LCI (07/2021 — 04/2025)
3 Series G28 Sedan LCI (07/2021 — 04/2025)
3 Series G21 Touring LCI (07/2021 — 03/2025)
4 Series G22 Coupé (06/2019 — 02/2024)
4 Series G22 Coupé LCI (02/2023 — 03/2025)
4 Series G23 Convertible (10/2019 — 02/2024)
4 Series G23 Convertible LCI (02/2023 — 03/2025)
4 Series G26 Gran Coupé (09/2020 — 07/2024)
4 Series G26 Gran Coupé LCI (06/2023 — 03/2025)
5 Series G30 LCI (07/2019 — 06/2023)
5 Series G31 Touring LCI (07/2019 — 02/2024)
X3 G01 (05/2018 — 08/2021)
X3 G01 LCI  (08/2020 — 08/2024)
Z4 G29 (10/2017 — 03/2025)