Description
Bmw B58 Exhaust 4.5in W/ Heatshied M340I B58 G20 G29 Downpipe is an application-led listing for buyers comparing this downpipe. The known vehicle context is BMW B58 Exhaust 4.5in w/ Heatshied M340i B58 G20 G29; confirm the exact model year, trim and body style before ordering.
This listing is part of our Exhaust Systems & Tips catalog.
Product overview
Unlock the full potential of your B58 engine with our High-Performance Exhaust Downpipe with Integrated Heat Shield, engineered to deliver massive gains in power, sound, and turbo efficiency. Designed as a direct bolt-on upgrade for B58-equipped vehicles, this downpipe significantly reduces backpressure, allowing your turbocharger to spool faster and breathe freely.
Precision-built for enthusiasts who demand performance without compromise, this downpipe features a high-flow design and a custom-fitted heat shield to protect surrounding components from radiant heat.
Key Features:
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High-Flow Design
Increases exhaust gas flow by reducing restrictions, resulting in improved turbo spool, throttle response, and horsepower gains. -
304 Stainless Steel Construction
Built from premium T304 stainless steel for long-term durability and corrosion resistance under high temperatures and harsh conditions. -
Integrated Heat Shield
Professionally fabricated heat shield protects engine bay components and reduces heat soak, ideal for daily drivers and track builds alike. -
CNC Machined Flanges
Ensures a perfect, leak-free fit with factory or aftermarket turbochargers and midpipes. -
Mandrel-Bent Tubing
Smooth, precision bends eliminate flow disruptions and turbulence for optimal performance. -
Factory Fitment & Easy Installation
Direct bolt-on replacement with no cutting or welding required. Retains use of OEM mounting points and O2 sensor locations. -
Optional 200 Cell High-Flow Catalytic Converter or Catless Configuration
Choose between catted (emissions-friendly) or catless (track use) options based on your performance goals. -
TIG-Welded for Strength & Aesthetics
Clean, strong welds ensure durability while giving a race-ready appearance.
Performance Gains:
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+15–25 HP (stock tune)
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+40+ HP (with tune)
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Noticeable reduction in turbo lag
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Enhanced exhaust sound and turbo spool
Vehicle Compatibility:
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2018–2023 BMW M340i (G20) – B58 3.0L Turbo I6
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2019–2023 BMW Z4 M40i (G29) – B58 3.0L Turbo I6
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2020–2023 Toyota GR Supra 3.0 (A90/A91) – B58 3.0L Turbo I6
B58 Exhaust 4.5in DownPipe w/ Heatshied – BMW M340i B58 G20 G29 Supra A90 B58 2018-2023 specifications
| Product | B58 Exhaust 4.5in DownPipe w/ Heatshied – BMW M340i B58 G20 G29 Supra A90 B58 2018-2023 |
|---|---|
| Vehicle application | BMW B58 Exhaust 4.5in w/ Heatshied M340i B58 G20 G29 |
| Part type | Downpipe |
| Material | Confirm available construction with our product team |
| Finish options | Confirm available finish options |
| SKU | -351031858 |
Fitment and buying notes for this downpipe
- Confirm inlet diameter, outlet shape, side, quantity and available clearance.
- Check compatibility with the factory or modified exhaust configuration.
- Heat, alignment and secure clamping should be reviewed by a qualified installer.
Product photos and titles are useful references, but they do not replace a fitment check. Send the make, model, model year, trim or chassis code, clear vehicle photos, required quantity and destination country before ordering.
Installation and order preparation
Mounting methods can vary by vehicle and product version. Do not assume a direct bolt-on installation unless it is confirmed for your exact application. Test fitting and professional installation are recommended, especially for structural, safety-related, electrical or large exterior parts.
For a faster quotation, specify the product SKU -351031858, the exact vehicle application, preferred material or finish, quantity and delivery location.
Frequently asked questions
How do I confirm whether this downpipe fits?
Share the exact vehicle year, trim, body style and any relevant chassis, engine or factory-option details. Our team can compare that information with the listing before quotation.
Can I choose a different finish or specification?
Available options depend on the part, construction and order quantity. Include the preferred weave, gloss or matte finish, color and any reference photos in your inquiry.
What should a wholesale inquiry include?
Include your company name, target quantity, destination country, required timeline and whether you need samples, repeat supply or custom packaging.











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