6 Inch B58 Downpipe for Supra 3.0T & BMW M240i/ 340i/ 440i/ 540i/ 640i/ 740i/ 840i/ X5/ Z4

The ARM 6" B58 Downpipe is one of the foundational upgrades for giving your B58-powered BMW more power, torque, and sound. The stock B58 downpipe comes from the factory with a catalyst that severely restricts exhaust flow, causing excessive backpressure with increased boost. Upgrading to the ARM 6" B58 Downpipe unlocks power, improves turbo spool, allows you to safely run stage 2+ tuning, all while improving the sound of your B58-powered BMW.

The ARM 6" B58 Catted Downpipe is perfect if you're looking for all of the performance of a Catless B58 Downpipe without the odor associated with increased emissions. Our B58 Catted Downpipe design incorporates a 6" high-flow 200 cell ceramic catalytic converter, making it a standout choice for those seeking power without while reducing emissions. The increased volume and improved turbo spool that from the catless variations are still present in our 6" B58 Catted Downpipe.

The ARM 6" Catted B58 Downpipe replaces the restrictive factory downpipe with a 200 cell catalyst with a 6" diameter that significantly improves exhaust flow. This upgrade unlocks additional power and torque while reducing emissions compared to a full catless B58 downpipe, allowing you to safely run Stage 2+ tunes and enjoy a more vibrant sound from your B58-powered BMW.

Highlights

• 6" 200 Cell High-Flow Catalyst
•  Improved Exhaust Sound
• Faster Turbo Spool
• Stage 2+ Tune Compatibility

ENHANCE THE SOUND OF YOUR B58

The ARM 6" B58 Catted Downpipe amplifies the overall volume of your B58's exhaust, bringing out the burbles and enhancing the audible presence of the turbo spool, even on the OEM tune.  Below is a sound clip of the ARM 6" Catless Downpipe, paired with our B58 Midpipe, and Single Exit Exhaust. 

CONSTRUCTION

The ARM 6" B58 Catted Downpipe starts with a 4.5" diameter precision CNC machined turbo V-band flange which matches up perfectly to the OEM turbo or upgraded turbo with an OEM flange.  It then rapidly transitions to the 6" OD high-flow catted section. 

The ARM 6" B58 Catted Downpipe features two O2 sensor bungs to allow for reinstallation of the OEM oxygen sensors.  The pre-catalyst O2 sensor bung is located closer to the turbo on the ARM 6" B58 Downpipe to avoid stretching the O2 sensor wires during installation.  The post-catalyst O2 sensor bung comes with a built-in extension to allow the sensor to reach around the 6" section of the downpipe.  

The ARM 6" B58 Downpipe then reduces to the OEM size to allow it to connect to the OEM midpipe or the ARM B58 Midpipe Upgrade.  The flex section is incorporated into the ARM 6" B58 Downpipe to relieve stress on the turbo during aggressive driving.

The ARM 6" B58 Downpipe is further secured by the 2-bolt bracket which utilizes the OEM downpipe mounting points.

Fitment

• 2019+ G20, G22 & G26 BMW M340i & M440i & xDrive
• 2019+ F22 BMW M240i & xDrive
• 2021+ G42 BMW M240i & xDrive
• 2019+ G05 BMW X5 40i & xDrive
• 2019+ G29 BMW Z4 M40i
• 2019+ G14/G15/G16 840i & xDrive
• 2019+ G14/G15/G16 840i & xDrive
• 2016+ F22/F23 BMW M240i & M240i xDrive
• 2016+ F30/F31 BMW 340i & 340i xDrive
• 2016+ F32/F33/F36 BMW 440i & 440i xDrive
• 2016+ G30 BMW 540i & 540i xDrive
• 2016+ G32 GT BMW 640i & 640i xDrive
• 2016+ G11/G12 BMW 740i & 740i xDrive
• 2020+ Supra A90/A91 3.0T

Every ARM Motorsports product is backed by a lifetime warranty which is automatically issued at the time of purchase. Your warranty protects you against any defects in craftsmanship or fitment. The warranty entitles you to a replacement unit.

We have a 30-day return policy, which means you have 30 days after receiving your item to request a return.

To be eligible for a return, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging. You’ll also need proof of purchase.

To start a return, you can contact us at palenonracing@gmail.com. If your return is accepted, we’ll send you instructions on how and where to send your package. Items sent back to us without first requesting a return will not be accepted.

You can always contact us for any return question at palenonracing@gmail.com.

Damages and issues
Please inspect your order upon reception and contact us immediately if the item is defective, damaged or if you receive the wrong item, so that we can evaluate the issue and make it right.

Exceptions / non-returnable items
Certain types of items cannot be returned, Burger Motorsports does not allow returns, custom products (such as special orders or personalized items), JB4 Tuners and air filters can not be returned. We also do not accept returns for hazardous materials, flammable liquids, or gases. Please get in touch if you have questions or concerns about your specific item.

Unfortunately, we cannot accept returns on sale items or gift cards.

Exchanges
The fastest way to ensure you get what you want is to return the item you have, and once the return is accepted, make a separate purchase for the new item.

Refunds
We will notify you once we’ve received and inspected your return, and let you know if the refund was approved or not. Certain circumstances will require a restocking fee of up to 25% at the discretion of Palenon Performance. (Examples of these circumstances include but are not limited to multiple failed delivery attempts, modified or damaged products and packaging, etc.) If approved, you’ll be automatically refunded on your original payment method. Please remember it can take some time for your bank or credit card company to process and post the refund too.

Handling

If the item is shipping from us direct, you will receive a tracking number within 1 business day. Most orders fulfilled at our warehouse will ship the same business day if ordered by 12pm MST. If the item is being drop shipped from the manufacturer, we cannot guarantee a tracking number within 1 business day. If an item is being drop shipped, we cannot guarantee the 24 hour (1 business day) processing time. A purchase of expedited shipping at checkout means that once item is ready to ship, it will ship using the upgraded shipping method. Some manufacturers require 3-5 days to process orders. Purchasing expedited shipping may speed up the processing time of your order, but we cannot make any guarantees in relation to faster processing time on the manufacturer’s end.

Cancellations

If you used a credit/debit card or PayPal to place an order and decide to cancel or return your order for any reason, a 5% merchant fee will be passed along to you (8% for Shop Pay installments). Some manufacturers can take up to 7 business days to ship out orders. If an item is out of stock we will reach out to you within 48 hours to confirm you would like to proceed with a preorder. If the item is listed as custom-built/ built to order within the description, or if the ETA or average lead time is visible on the product page at the time of ordering and you are cancelling inside of that ETA/lead time you will be charged the merchant fee. If the cancellation is outside of the time frame the merchant fee will not be charged to you for canceling.