- Description
- Fitment
- Refund Policy
HIGHLIGHTS
• Improved Exhaust Sound
• Faster Turbo Spool
PROFILE
The ARM 6" B58 Downpipe takes the title of being the largest catless downpipe available for the B58 platform! The sound coming from your B58 with the 6" section of the ARM B58 Downpipe will astonish you. Even deeper tones, even better sound, and improved turbo spool.

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.
ENHANCE THE SOUND OF YOUR B58
CONSTRUCTION
The ARM 6" B58 Downpipe is built with SS304 stainless steel and is TIG welded. The ARM 6" B58 Downpipe starts with a 4.5" diameter precision CNC machined turbo V-band flange which rapidly transitions to the 6" OD high-flow section.

The ARM 6" B58 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 3.1" diameter 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.

IN THE BOX
FITMENT GUIDE
| Make | Model | Submodel | Engine |
|---|---|---|---|
| BMW | F22 | M240i | B58 3.0L |
| BMW | F22 | M240i xDrive | B58 3.0L |
| BMW | F23 | M240i | B58 3.0L |
| BMW | F23 | M240i xDrive | B58 3.0L |
| BMW | F30 | 340i | B58 3.0L |
| BMW | F30 | 340i xDrive | B58 3.0L |
| BMW | F32 | 440i | B58 3.0L |
| BMW | F32 | 440i xDrive | B58 3.0L |
| BMW | F33 | 440i | B58 3.0L |
| BMW | F33 | 440i xDrive | B58 3.0L |
| BMW | F34 | 340i xDrive | B58 3.0L |
| BMW | F36 | 440i | B58 3.0L |
| BMW | F36 | 440i xDrive | B58 3.0L |
| BMW | G30 | 540i | B58 3.0L |
| BMW | G30 | 540i xDrive | B58 3.0L |
| BMW | G32 | 640i | B58 3.0L |
| BMW | G32 | 640i xDrive | B58 3.0L |
| BMW | G12 | 740i | B58 3.0L |
| BMW | G12 | 740i xDrive | B58 3.0L |
| BMW | G15 | 840i | B58 3.0L |
| BMW | G15 | 840i xDrive | B58 3.0L |
| BMW | G05 | X5 40i | B58 3.0L |
| TOYOTA | A90 | Supra | B58 3.0L |
| TOYOTA | A91 | Supra | B58 3.0L |
This product is for Off-Road Use Only. Items sold for off-road use only are illegal to use on public roads in most states and provinces. This product is intended for racing vehicles which may never be used on a public road.
Returns
Our policy lasts 14 days. If 14 days have gone by since your purchase, unfortunately we can’t offer you a refund or exchange. All items are subject to 15% restocking fee from the manufacturer.
To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.
Additional non-returnable items:
Gift cards
Downloadable software products
To complete your return, we require a receipt or proof of purchase.
Please do not send your purchase back to the manufacturer.
There are certain situations where only partial refunds are granted (if applicable)
You will be responsible for paying for your own shipping costs for returning your item. Shipping costs are non-refundable. If you receive a refund, the cost of shipping to you will be deducted from your refund. If your original order qualified for free shipping, the actual cost of shipping the item to you will still be deducted from your refund.
If you would like to start a return please click here
Refunds (if applicable)
Once your return is received and inspected, we will send you an email to notify you that we have received your returned item. We will also notify you of the approval or rejection of your refund.
If you are approved, then your refund will be processed, and a credit will automatically be applied to your credit card or original method of payment, within a certain amount of days.
You will be responsible for paying for your own shipping costs for returning your item. Shipping costs are non-refundable. If you receive a refund, the cost of shipping to you will be deducted from your refund. If your original order qualified for free shipping, the actual cost of shipping the item to you will still be deducted from your refund.
Late or missing refunds (if applicable)
If you haven’t received a refund yet, first check your bank account again. Then contact your credit card company, it may take some time before your refund is officially posted. Next contact your bank. There is often some processing time before a refund is posted. If you’ve done all of this and you still have not received your refund yet, please contact us at info@amtuning.ca.
Sale items (if applicable)
Only regular priced items may be refunded, unfortunately sale items cannot be refunded.
Labor Fees (if applicable)
AM Tuning Canada is not responsible for, and shall not be liable for, any labor fees, installation charges, removal charges, diagnostic fees, or other service-related costs incurred by the customer or any third party in connection with the installation, removal, modification, servicing, or use of any products purchased from AM Tuning Canada. Unless expressly agreed to in writing by AM Tuning Canada, all such labor and service costs are the sole responsibility of the customer.
Exchanges (if applicable)
To start an exchange, click here
Non-refundable items
The following items are non-refundable and non-returnable once purchased: oils, fuel or oil additives, filters, tuning cables, OBDeleven products, Braum seats, spark plugs, coil packs, and similar consumable, wheel spacers, wheels bolts, license plate brackets, electronic tuning components and any other product subject to discretion of AM Tuning Canada.
Other products from brands such as MHD, Bootmod3, Ecutek, Braum racing, Novitec are also non-refundable and non-returnable.
All sales of these items are final and are subject to the policies and discretion of AM Tuning. By completing a purchase, the customer acknowledges and agrees to these terms.
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