3-Series |4-series| Supra - B58 Downpipes

Q: Do you offer financing or payment plans?

Yes. At checkout, you can use Shop Pay Installments or Affirm to split your purchase into easy monthly payments. Financing options, including potential 0% interest plans, are shown during checkout and are subject to approval.

$275.00 $400.00

🔥 BOGO DEAL: Buy 1, Get 30% OFF Your 2nd Item

Product variants

Pickup available at LAB X Premium

Usually ready in 24 hours

In Stock • Ships in 1–2 Business Days (from California Warehouse)

Fast fulfillment + tracking on every order

2-Year Warranty Included

Covers manufacturing defects

Fitment Guaranteed

Verified compatibility for listed BMW models

Questions? Call (424) 483-1280

Talk to a real product expert

Pairs well with

LAB B58 Downpipes – Track Use Only

Unleash the true performance of your B58 engine with our LAB B58 Downpipes. Designed for maximum power gains and faster turbo spool, these downpipes eliminate the restrictive stock catalytic converters, dramatically improving exhaust flow and throttle response.

Our precision-engineered flex section minimizes stress and vibration to protect both your turbo system and chassis under high-load conditions.

Important: These downpipes are for track use only. We cannot ship to Southern California unless you are a licensed performance shop. Contact your local shop to order them from us.

Performance Benefits:

Reduces turbo lag and increases spool efficiency
Optimized for maximum horsepower and torque gains
Designed to handle extreme temperatures and boost levels
Up to 25–30HP gains on a tuned B58 with stock turbo

Features:

CNC-machined flanges for OEM-like fitment
Smooth, mandrel-bent 4" piping for unrestricted flow
Integrated flex section to reduce vibration and drivetrain stress
TIG-welded stainless steel construction for durability
Drone-free aggressive exhaust note under load

Fitment:

🟢 Gen 2 B58 Downpipes (B58B30O1 / B58TU)

Non-hybrid B58 found in G-chassis and A90/A91 Supra — 2019 to ~2024

BMW (Non-Hybrid G-Chassis):

2020–2024 BMW M340i (G20)
2021–2024 BMW M440i (G22/G23/G26)
2019–2024 BMW X3 M40i (G01)
2019–2024 BMW X4 M40i (G02)
2021–2024 BMW 540i (G30)
2021–2024 BMW 740i (G11/G12)
2020–2024 BMW Z4 M40i (G29)

Toyota:

2020–2024 Toyota GR Supra 3.0 / 3.0 Premium / A91 (MKV)

🟣 Gen 3 B58 Downpipes (B58B30M2 / B58TU2)

Hybridized “mild-hybrid” B58 (with 48V system) starting ~late 2024 into 2025+

BMW (Hybrid G-Chassis – LCI or G2 models):

2025+ BMW M340i (G20 LCI w/ 48V MHEV)
2025+ BMW M440i (G22/G23/G26 LCI w/ MHEV)
2025+ BMW X3 M40i (G45, new-gen chassis)
2025+ BMW X4 M40i (G46, new-gen chassis)
2025+ BMW Z4 M40i (G29, MHEV updated version)
2025+ BMW 540i (G60 hybridized)
2025+ BMW 740i (G70)

Toyota:

✅ Not Applicable. Toyota has not released a hybrid B58 Supra (yet). All Supra B58s remain Gen 2.

3-Series |4-series| Supra - B58 Downpipes

Gen 2

$275.00 $400.00

FreshhKiicks Install

When it comes to proper builds, FreshhKiicks knows what is takes to stand out. That's why he chose to go with LAB parts for his LCI X3M.

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Split your purchase into easy payments at checkout. No hidden fees.

Easy Monthly Payments

Split your total into flexible installments

Affirm Financing Available

0% interest options may be available*

*Payment plans shown at checkout. Subject to eligibility and approval.

FAQs

Do you offer financing or payment plans?

Yes. At checkout, you can use Shop Pay Installments or Affirm to split your purchase into easy monthly payments. Financing options, including potential 0% interest plans, are shown during checkout and are subject to approval.

Will this part fit my BMW?

Yes. Every product we sell is verified for specific BMW models and chassis. If you want extra peace of mind, you can send us your model, year, or VIN and our team will personally confirm fitment before you order. BMW fitment accuracy is a priority at Legendary Auto Builders.

Are your parts OEM-quality or aftermarket replicas?

We only carry high-quality aftermarket parts that meet or exceed OEM standards. Each product page clearly outlines materials, construction, and finish so you know exactly what you’re getting. We do not sell low-grade replicas or poorly made components.

Where do you ship from and how long does shipping take?

Most in-stock orders ship from our California warehouse within 1–2 business days. Standard U.S. delivery typically takes 3–7 business days depending on location. Made-to-order or specialty items may require additional production time, which is always noted on the product page.

Can I install this myself, or do I need a professional?

Many of our products are designed for direct bolt-on installation and can be installed at home with basic tools. For more complex parts—such as aero components or performance upgrades—we recommend professional installation for best results. If you have questions about install difficulty, just reach out.

What happens if the part doesn’t fit my vehicle?

If there’s a fitment issue due to an error on our end, we’ll make it right. Our team will help resolve the issue quickly, whether that means an exchange or another solution. Fitment accuracy matters to us, and we stand behind the products we sell.

Are your products tested for quality and durability?

Yes. All products go through quality checks and are sourced from trusted manufacturers. We work closely with suppliers and installers to ensure every part meets our performance and durability standards before it ever reaches your car.

Do your products come with a warranty?

Most items include a warranty covering manufacturing defects. Warranty length and coverage details vary by product and are listed on the product page. If you ever have a concern, our support team is here to help.