“The most advanced K04 hybrid upgrade ever for the Porsche 718 2.0L — full porting, extrude-honed housings, 500+ HP capable.”

Maximum Flow. Relentless Power. Race-Level Engineering.

*This listing is for a RaggDoll series turbo build using a brand new and complete Borg Warner turbocharger as a core.

The RaggDoll Rennen HF turbocharger is the next evolution of performance for the Porsche 718 2.0L platform — a weaponized version of our already class-leading Rennen turbo. Building on the proven architecture that outperforms every other K04 hybrid available for the 2.0L Porsche 718, the Rennen HF takes things even further with extensive race-style housing porting and full extrude honing for the ultimate in airflow and response.

Paired with our upgraded fuel system and RaggDoll supporting mods, the Rennen HF delivers 500+ crank horsepower on pump gas — with faster spool, even bigger midrange torque, and stronger top-end power than any other bolt-on solution for the Porsche Cayman Boxster and T 982 2.0L platform.

RaggDoll Rennen HF Features

• True Plug-and-Play: Direct bolt-on, no modifications required.
• Exclusive Race-Ported Housings: Extensive compressor and turbine port work to maximize flow.
• Extrude Honed for Ultimate Flow: Deep polishing and smoothing of all critical internal pathways and wastgate.
• Advanced Compressor Design: Maximum efficiency and broader torque powerband.
• High-Flow Turbine Wheel: Fast spool with unbeatable top-end breathing.
• Genuine BorgWarner Cartridge: Built from OEM-quality internals and housings.
• Inconel Turbine Wheel: Handles extreme 1050°C (1922°F) exhaust temperatures reliably.
• Cooler IATs Under Boost: Increased airflow at lower boost pressure means lower intake temps and more stable performance.
• Track-Tested, Dyno-Proven: Real-world performance you can count on.

What Porting and Extrude Honing Does for a Turbocharger

Housing Porting:

Careful, race-style porting of the compressor and turbine housings improves turbocharger performance by:

• Reducing airflow restrictions through the housing passages.
• Smoothing abrupt transitions and sharp edges that cause turbulence and backpressure.
• Allowing higher volume and velocity of air to move through the turbo, helping the turbo spool faster and produce more power with less effort.
• Minimizing unwanted pressure drops across the housings for a more efficient pressure ratio.

In the Rennen HF, the turbine inlet, volute passages, and compressor cover transitions have all been aggressively optimized for maximum gas and air flow while preserving velocity.

Extrude Honing:

Extrude honing takes the porting process even further by using a high-pressure abrasive media that is forced through the turbo’s internal passages. This process:

• Perfectly smooths and enlarges all airflow paths beyond what hand or machine porting alone can achieve.
• Eliminates microscopic surface imperfections that cause boundary layer drag.
• Creates extremely uniform surface finishes for the absolute maximum airflow and gas evacuation.
• Ensures consistency across every unit — no two turbos are exactly alike without extrude honing.

Combined, porting and extrude honing allow the Rennen HF to move significantly more air and exhaust energy than any other small-frame K04-based hybrid — without needing oversized, lag-inducing housings.

Designed for Maximum Real-World Performance

The Rennen HF was born from extensive track and dyno testing across dozens of 718 builds, ensuring

• Faster Spool: Builds boost earlier and harder.
• Wider Powerband: Midrange torque hits harder, and top-end power carries further.
• Higher Efficiency: Less heat, lower backpressure, and more consistent output, lap after lap.
• OEM Reliability: Maintains factory-like driveability and reliability with dramatically upgraded performance.

Our Proprietary Compressor and Turbine Pairing

• Advanced, High-Flow Compressor Wheel: Designed to maximize efficiency and mass airflow without the surge or lag of older designs.
• High-Flow Turbine Wheel: Perfectly matched to the compressor to deliver superior turbine-to-compressor flow balance.
• Race-Ported and Extrude Honed Housings: Complements the wheel designs to unleash every ounce of power potential.

We strongly recommend pairing the Rennen HF with the RaggDoll High-Flow Turbo Inlet to allow the turbo to breathe to its full potential.

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