BMW N55 Downpipe For 2010-2013 E8x 135i, E9x 335i - ARM Motorsports

The ARM E-Series N55 Downpipe is engineered to increase power and performance for BMW vehicles equipped with the N55 engine. By optimizing exhaust flow and reducing back pressure, this upgrade allows your turbocharged engine to perform more efficiently.

Upgrading the downpipe on your N55 improves turbo response, increases horsepower and torque, and enables Stage 2+ tuning. It also enhances the overall exhaust sound of your 135i or 335i, making it deeper and more aggressive.

The ARM N55 Downpipe is designed for direct fitment and is compatible with both OEM and aftermarket midpipes. It features an 80mm V-Band flange, allowing it to work with both standard factory turbochargers and upgraded turbo setups.

For N55 owners seeking more power, a downpipe upgrade is one of the first and most effective hardware modifications.

Highlights

• Gain up to 21 WHP / 27 WTQ
• Faster turbo spool
• Improved exhaust sound
• Supports Stage 2+ tuning
• Constructed from SS304 stainless steel

Improved Exhaust Sound

Beyond performance gains, the ARM N55 Downpipe significantly enhances exhaust sound.

Thanks to its 4.5-inch middle section, the downpipe produces a deeper and more aggressive exhaust note, especially during cold starts and full-throttle acceleration. This design creates a more pronounced and sporty sound compared to standard 3-inch downpipe upgrades.

Construction

The ARM N55 Downpipe is built using high-quality TIG-welded SS304 stainless steel for durability and long-lasting performance.

Key construction features include:

• Precision CNC-machined 80mm V-Band flange compatible with OEM and upgraded N55 turbos

• Integrated flex section welded directly after the flange to reduce stress on the turbo during aggressive driving

• Large 4.5-inch middle section to improve exhaust flow and enhance sound

The downpipe transitions from the 4.5-inch center section into dual 2.5-inch flanges at the midpipe connection. This allows seamless integration with both OEM and aftermarket midpipes designed for the factory N55 layout.

Additionally, the downpipe includes two O2 sensor bungs, allowing you to reinstall the OEM oxygen sensors. These bungs are positioned higher on the pipe to prevent stretching the sensor wiring during installation.

In the Box

• ARM N55 Downpipe

• 2 × Midpipe gaskets

• 4 × Bolts, washers, and nuts

Fitment Guide

The ARM E-Series N55 Downpipe is designed for the following BMW vehicles equipped with the N55 3.0L engine:

ARM Motorsports Lifetime Warranty

Every ARM Motorsports product is backed by a lifetime warranty, automatically issued at the time of purchase.

This warranty protects against defects in craftsmanship or fitment and entitles you to a replacement unit if a manufacturing defect occurs.

Handling

Orders shipped directly from our warehouse are usually processed the same business day if placed before 12 PM MST, and tracking details are provided within 1 business day.

For drop-shipped items, processing times may vary depending on the manufacturer, typically 3–5 business days. Tracking updates may take longer in such cases.

Expedited shipping applies only once the item is ready to ship.

Return

You have 30 days after receiving your order to request a return. Items must be unused, in original packaging, and include proof of purchase. Customers are responsible for covering the return shipping costs.

To start a return, email us at sales@palenonperformance.com. Returns sent without approval will not be accepted.

You can request a return directly from your account by selecting the return option on your order page. Here is the URL: https://shopify.com/55092379855/account/orders

Non-returnable items:

• Burger Motorsports (BMS) products
• Used items
  
• Air Intakes
• Hazardous materials, flammable liquids, or gases
• Discounted items and gift cards other than "PALENON PERFORMANCE" brand 

Exchanges

Return the item and place a new order once approved.

Refunds

Approved refunds are issued to the original payment method. A restocking fee is 20% will be applied. Processing time depends on your bank or payment provider. The original shipping cost will not be refunded.

Cancellations

Canceled orders are subject to a 5% merchant fee (8% for Shop Pay installments). Custom, specialized items or pre-order items canceled within their lead time are also subject to this fee. Will also incur a 10% restocking fee.

Damaged or incorrect items

Inspect your order upon arrival and contact us immediately for assistance. If the wrong part was ordered, customer covers return shipping.

Disputes / Chargebacks

Our legal team is fully prepared to take stringent action against you for filing a baseless claim and initiating a fraudulent chargeback. This will lead to civil or criminal proceedings, which would require you to engage with our attorneys in our jurisdiction.

It is crucial to understand that filing a false chargeback is a serious offense, punishable by substantial fines or imprisonment. Potential penalties for fraudulent chargebacks can include one to three years in prison and fines ranging from $1,000 to $10,000. We treat all chargebacks with the utmost seriousness, regardless of the amount, as this is classified as a felony.

We will compose all necessary information to send your account to a collections agency and request that you be served once our lawyers organize the evidence and file a case against you.