- Description
- Fitment
- Refund Policy
G90 Signature Catback Exhaust System
Stainless Steel Valved Full Exhaust System – BMW G90 M5 (S68 Twin-Turbo V8-Hybrid)
Transform the performance and sound of your 2025+ BMW G90 M5 with our premium T304 stainless steel valved full exhaust system. Purpose-built for the S68 4.4L twin-turbo V8, this system is engineered to enhance exhaust flow, reduce backpressure, and deliver a deep, aggressive tone—without compromising daily drivability.
Designed using advanced techniques for a precise OEM-fit, this exhaust system integrates seamlessly with all factory mounting points and adds exhaust valve control which is missing from the OEM exhaust system. Whether cruising or pushing the limits, this system provides an immersive and exhilarating exhaust experience.
Key Highlights:
T304 Stainless Steel Construction: Built entirely from corrosion-resistant, mandrel-bent T304 stainless steel, this system offers long-term durability, heat resistance, and a consistent finish. Welded with precision using TIG methods to ensure structural integrity and leak-free performance under high-load conditions.
Remote control Exhaust Valves: Adds an electronic valve system controlled by a remote to replace the missing exhaust valves BMW did not provide with the stock exhaust. Provides a quiet, subdued tone in comfort modes and an aggressive, open-valve growl in dynamic settings—no tuning or coding required.
High-Flow X-Pipe Midsection: Centralized X-pipe balances exhaust pulses between banks, improving scavenging and enhancing the natural V8 rhythm. Reduces unwanted drone and enhances top-end acoustics under throttle.
Performance-Oriented Flow Path: Oversized and optimized 3.5” (89mm) piping diameter ensures efficient flow, minimizes turbulence, and maximizes power delivery throughout the rev range. Estimated gains of +18–22 hp and +20–25 lb-ft torque (with optional EPA catted downpipes).
Optional High-Flow Catted Downpipes: Available as an upgrade, our 400-cell GESI catalytic converters maintain emissions compliance (region-dependent) while increasing turbo efficiency and reducing spool time. CNC-machined flanges and heat shielding ensure fitment and thermal control.
Sound Engineering: Precision-tuned for a refined cold start, deep idle rumble, and aggressive throttle response. The system delivers a clean, motorsport-inspired tone without unwanted cabin drone—ideal for both spirited driving and long highway trips.
Quad 112mm Exhaust Tips (Multiple Finishes): Choose from brushed stainless, matte black or carbon fiber quad tips to match your M5’s styling. Dual-wall design resists heat discoloration and adds a premium finish to the rear profile.
Direct Bolt-On Installation: No cutting, welding, or modification required. Includes all clamps, gaskets, valve motor brackets, valve motors with remotes and hardware. Fully reversible for lease or resale.
Specifications:
•Material: T304 Stainless Steel
•Tubing Diameter: 3.5” (89mm) from downpipes to rear exhaust
•Valves: Electronic remote control plug-and-play
• Weight Reduction: ~10–12 lbs vs. OEM system
•Tip Diameter: 112mm (quad outlet)
•Fitment: BMW G90 M5 (2025+) / G99 M5 Touring
Why Choose This Exhaust System?
This full stainless system offers the perfect balance of durability, sound tuning, and performance gains—without sacrificing luxury or OEM integration. Ideal for enthusiasts looking for a visceral exhaust experience with the peace of mind of factory compatibility and high-quality materials.
Unlock the full potential of your G90 M5. Let it breathe, let it roar.
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.
