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MAGNAFLOW 49791 Manifold Catalytic Converter OEM Grade for BMW 750Li 2006-2008 Photo-0
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MAGNAFLOW 49842 Manifold Catalytic Converter OEM Grade for FORD Focus 2005-2007 Photo-0
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MAGNAFLOW 49850 Manifold Catalytic Converter OEM Grade for FORD Focus 2008-2010 Photo-0
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MAGNAFLOW 49790 Manifold Catalytic Converter OEM Grade for BMW 745i 2004-2005 Photo-0
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MAGNAFLOW 49780 Catalytic Converter Direct-Fit OEM Grade for BMW 535i 2008-2010 Photo-0
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MAGNAFLOW 49784 Manifold Catalytic Converter OEM Grade for BMW 540i 1999-2003 Photo-0
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MAGNAFLOW 49834 Manifold Catalytic Converter OEM Grade for TOYOTA Sienna 2004-2006 Photo-0
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MAGNAFLOW 49839 Manifold Catalytic Converter OEM Grade for FORD Focus 2005-2007 Photo-0
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MAGNAFLOW 49783 Manifold Catalytic Converter OEM Grade for BMW 540i 1999-2003 Photo-0
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MAGNAFLOW 49772 Manifold Catalytic Converter OEM Grade for BMW 525i 2001-2003 Photo-0
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MAGNAFLOW 49779 Catalytic Converter Direct-Fit OEM Grade for BMW 535i 2008-2010 Photo-0
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MAGNAFLOW 49806 Catalytic Converter Direct-Fit OEM Grade for MERCEDES-BENZ C32 AMG 2002-2004 Photo-0
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MAGNAFLOW 49833 Manifold Catalytic Converter OEM Grade for LEXUS RX330 2004-2006 Photo-0
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MAGNAFLOW 49775 Manifold Catalytic Converter OEM Grade for BMW 525i 2006-2007 Photo-0
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MAGNAFLOW 49767 Catalytic Converter Direct-Fit OEM Grade for BMW 335i (90) Photo-0
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MAGNAFLOW 49796 Manifold Catalytic Converter OEM Grade for BMW M3 (E46) Photo-0
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MAGNAFLOW 49805 Catalytic Converter Direct-Fit OEM Grade for MERCEDES-BENZ C32 AMG 2002-2004 Photo-0
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MAGNAFLOW 49771 Manifold Catalytic Converter OEM Grade for BMW 525i 2004-2005 Photo-0
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MAGNAFLOW 49770 Manifold Catalytic Converter OEM Grade for BMW 525i 2004-2005 Photo-0
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MAGNAFLOW 49762 Manifold Catalytic Converter OEM Grade for BMW 325i / 328i / 330i (E90) Photo-0
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MAGNAFLOW 49795 Manifold Catalytic Converter OEM Grade for BMW M3 (E46) Photo-0
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MAGNAFLOW 49789 Manifold Catalytic Converter OEM Grade for BMW 745i 2004-2005 Photo-0
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MAGNAFLOW 49766 Catalytic Converter Direct-Fit OEM Grade for BMW 335i (90) Photo-0
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MAGNAFLOW 49765 Catalytic Converter Direct-Fit OEM Grade for BMW 325i / 328i / 330i (E90) Photo-0
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MAGNAFLOW 49753 Catalytic Converter Direct-Fit OEM Grade for NISSAN Micra 2015-2019 Photo-0
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MAGNAFLOW 49782 Catalytic Converter Direct-Fit OEM Grade for BMW 535i 2008-2010 Photo-0
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MAGNAFLOW 49786 Catalytic Converter Direct-Fit OEM Grade for BMW 540i 1999-2003 Photo-0
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MAGNAFLOW 49760 Catalytic Converter Direct-Fit OEM Grade for BMW 325Ci 2003-2003 Photo-0
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MAGNAFLOW 49759 Manifold Catalytic Converter OEM Grade for BMW 325Ci 2001-2006 Photo-0
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MAGNAFLOW 49781 Catalytic Converter Direct-Fit OEM Grade for BMW 535i 2008-2010 Photo-0
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MAGNAFLOW 49774 Manifold Catalytic Converter OEM Grade for BMW 525i 2006-2007 Photo-0
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MAGNAFLOW 49743 Catalytic Converter Direct-Fit OEM Grade for AUDI RS6 (C5) 2003-2004 Photo-0

Building a Stronger Engine: A Guide to Performance Internals

The quest for more horsepower inevitably leads to the heart of the car: the engine internals. Factory components are designed for stock power levels and can become a critical failure point under increased stress. Upgrading to high-performance internals is the only way to build a powerful and reliable engine. This guide explains the core component groups, which you can explore using our navigation above.

The Anatomy of a Built Engine

  • Pistons: The foundation of power. Upgrading from brittle cast factory pistons to strong, lightweight forged pistons is the first step in preparing an engine for serious boost or RPM.
  • Connecting Rods: The link between the pistons and the crankshaft. Forged steel H-beam or I-beam rods are exponentially stronger than stock and are essential for preventing catastrophic failure.
  • Camshafts & Valvetrain: The "lungs" of your engine. Performance camshafts have more aggressive profiles (lift and duration) to let more air in and out, while upgraded valve springs prevent valve float at high RPM.
  • Engine Hardware & Studs: The bolts that hold it all together. Factory head and main bolts can stretch under high cylinder pressures. Upgrading to high-strength studs from ARP is mandatory to prevent head gasket failure.

When Do You Need to Build Your Engine?

Power Level Typical Requirement
Stage 1-2 (Bolt-ons) Stock internals are generally safe.
Medium Build (Upgraded Turbo) Forged Pistons & Connecting Rods are highly recommended.
High-Horsepower Build A "fully built" engine is required: Pistons, Rods, Head/Main Studs, Bearings, Valvetrain.