Product Overview
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Brand: HMD
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Fitment: Alfa Romeo Stelvio Quadrifoglio 2.9T
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Product Type: Variable-Valve Exhaust System (Catback)
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Product Name: Racing-Grade Catback Performance Exhaust
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Vehicle Fitment: After placing your order, please send your vehicle details to customer service.
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Model Years: Please confirm the exact model year before ordering.
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Material: 304 Stainless Steel
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Surface Finish: Polished / Brushed / Sandblasted Stainless Steel (depending on version)
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Valve Control: This system comes standard with a precision bracket designed to accommodate your vehicle's original OEM valve motor. No aftermarket remote control is needed — the valve operates directly through your car's factory ECU logic, automatically opening and closing based on RPM, throttle position, and drive mode.
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Welding Method: TIG Hand-Welded
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Installation Type: Direct OEM replacement — plug-and-play, no cutting, no welding required.
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Performance Improvement: Optimized exhaust flow with reduced backpressure
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Modification Results: Enhanced turbo response and improved exhaust efficiency
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Installation Note: Professional installation is strongly recommended.
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Logo Customization: Free laser logo engraving available
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Warranty: 2 Years
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Place of Origin: Made in China
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Contact (WeChat / WhatsApp / Kakao Talk): +86 18924479531
Stainless Steel Valved Exhaust System — The Smart Choice for Performance & Sound
I. Product Overview
What is an OEM-Integrated Valved Exhaust System?
In simple terms, this is a high-performance exhaust system equipped with a valve mechanism that is directly driven by your vehicle's factory original motor. Instead of relying on an external remote control or aftermarket vacuum lines, the system uses a precision-engineered bracket to mount your OEM valve motor, allowing the exhaust valve to follow your car's original ECU programming seamlessly.
It Solves the Dilemma of Traditional Exhausts:
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Chambered / Closed-Loop Design — Good low-end torque, but restricted airflow at high RPM limits peak power.
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Straight-Through Design — Strong top-end horsepower, but noticeable low-end torque loss with excessive noise.
Our Valved System Combines the Best of Both Worlds:
When the valve is closed, exhaust gases travel through a smaller-diameter or single pipe, maintaining adequate backpressure to preserve low-end torque for city driving. When the valve opens (automatically triggered by the factory ECU based on engine load and RPM), gases flow through a larger-diameter or dual-path design, dramatically reducing backpressure to unlock full high-RPM horsepower.
II. Key Product Advantages
Premium Stainless Steel Construction
Crafted from high-grade 304 stainless steel, our exhaust systems offer outstanding heat resistance (withstanding up to 1050°C) and superior corrosion protection, ensuring long-term durability under extreme exhaust temperatures. Precise wall-thickness control also contributes to effective weight reduction.
Seamless OEM-Level Control
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Plug-and-Play with Factory Motor — No remote controls, no extra wiring. The system uses your car's original valve motor mounted on our custom bracket, making installation clean and completely reversible.
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ECU-Driven Logic — The valve operates automatically according to your vehicle's factory engine management system, responding in real time to throttle position, RPM, and selected drive mode (e.g., Comfort vs. Sport). No manual intervention is needed — the system simply works as the manufacturer intended.
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Full Retention of Factory Functions — All original electronic features remain intact. The exhaust behaves like a factory performance option, giving you intelligent, adaptive sound and power delivery.
Dual Enhancement – Performance & Sound
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Valve Closed (Daily / Comfort Mode) — A deep, mellow tone (~80–85 dB), near-stock sound levels, making it perfect for daily commuting, residential areas, and highway cruising with zero drone.
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Valve Open (Sport / Performance Mode) — Unleashes an aggressive, high-pitched roar accompanied by sharper throttle response and noticeably smoother high-RPM power delivery — giving you the full performance experience whenever the engine demands it.
Bolt-On / Direct-Fit Installation
Designed for a true direct-fit replacement of your factory catback section. No cutting, no welding, and 100% reversible. Installation is straightforward and hassle-free with basic hand tools.
III. Application Scenarios
Daily Commute & Highway Cruising
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Valve State: Closed (automatically controlled by OEM ECU)
Quiet and comfortable with near-stock exhaust volume — perfect for stop-and-go traffic and long-distance drives without driver fatigue.
Weekend Canyon Runs & Track Days
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Valve State: Open (automatically engaged by OEM ECU under load)
Unleash your engine's full potential with aggressive high-RPM response and a roaring exhaust note — making every spirited drive truly exhilarating.
Late-Night Returns
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Valve State: Closed (via factory comfort mode)
One-touch (drive-mode select) quiet operation — no more worrying about disturbing neighbors when coming home late.
Car Shows & Enthusiast Meetups
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Valve State: Open (triggered by sport-mode activation)
Turn heads with a commanding exhaust presence that showcases your unique taste in high-performance modification.
IV. Product List
Compatible Models: Alfa Romeo Stelvio Quadrifoglio 2.9T
(If you are unsure whether this product fits your vehicle, please contact customer service for confirmation.)
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High-performance catback exhaust system (with OEM motor mounting bracket) — 1 set
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Mounting hardware and screw kit
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Installation manual
V. Why Choose Us?
● In-house factory production — direct quality control and competitive pricing
● Broad vehicle coverage with customization options available
● Premium 304 stainless steel — durable, rust-proof, and built to last
● Comprehensive after-sales technical support
● OEM / ODM orders are welcome
VI. Contact Us
Interested in learning more or requesting a custom quote? Reach out to us:
Email: OUCHIEXHAUST009@gmail.com
WhatsApp / Kakao Talk: +86 18924479531