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Carbon-Tipped Titanium Sound for the 991 Turbo: Akrapovic S-PO991TSO-HT Slip-On Line
The Akrapovic S-PO991TSO-HT Slip-On Line exhaust in titanium with carbon titanium tips delivers the signature Akrapovic sound character to the 2014 and 2015 Porsche 911 Turbo and 911 Turbo S (991 generation) without touching the headers or secondary pipes. By replacing only the rear muffler section, the S-PO991TSO-HT achieves a substantial weight reduction while transforming the 3.8L twin-turbocharged flat-six soundtrack into a deeper, sportier exhaust note with zero highway drone. The carbon titanium oval tips provide a race-inspired visual finish that complements the 991 Turbo's aggressive rear end design.
Key Features
- Slip-On design replaces the OEM muffler section only for a straightforward bolt-on installation
- Grade-1 titanium construction for maximum weight savings over the factory exhaust
- Carbon titanium oval exhaust tips included for a premium race-inspired appearance
- Engineered to retain the Porsche PDCC and PSM exhaust valve compatibility
- Compatible with the Akrapovic Sound Kit for electronically controlled valve operation
- Deep, sporty, higher-frequency exhaust note without drone at highway cruise
- Street-legal design maintaining factory catalyst and emissions equipment
- Precision TIG-welded titanium joints built to Akrapovic aerospace tolerances
- Fits both 911 Turbo and 911 Turbo S variants of the 991 generation
- Developed and validated through Akrapovic's engineering test program on the 991 platform
Fitment
| Year Range | Make | Model | Trim |
|---|---|---|---|
| 2014-2015 | Porsche | 911 | Turbo |
| 2014-2015 | Porsche | 911 | Turbo S |
Specifications
| Detail | Value |
|---|---|
| Part Number (MPN) | S-PO991TSO-HT |
| System Type | Slip-On Line (Muffler Replacement) |
| Material | Grade-1 Titanium |
| Tip Style | Carbon Titanium Oval |
| Compatible Engine | 3.8L Twin-Turbo Flat-Six |
| Generation | 991 (2012-2015) |
| Sound Kit Compatible | Yes (Akrapovic Sound Kit sold separately) |
| Emissions | Catalyst and emissions equipment retained |
| Brand | Akrapovic |
| Country of Manufacture | Slovenia |
| UPC | 3831113527163 |
What's Included
- Akrapovic S-PO991TSO-HT titanium slip-on muffler assembly
- Carbon titanium oval exhaust tips
- All required mounting hardware and clamps
- Akrapovic installation instructions
Frequently Asked Questions
What Porsche 911 models does the Akrapovic S-PO991TSO-HT fit?The S-PO991TSO-HT fits the 2014 and 2015 Porsche 911 Turbo and 911 Turbo S in the 991 generation body style. It does not fit the 991.2 (2016 and later) Turbo or Turbo S, nor does it fit naturally aspirated 911 Carrera variants.
What is the difference between a Slip-On and a full cat-back exhaust?A Slip-On system replaces only the rear muffler section of the exhaust while leaving the mid-pipes and catalytic converters in place. Installation is typically faster and the modification is more reversible than a full cat-back. You still gain significant weight savings and a dramatic sound improvement, but a full cat-back system would yield additional power gains through reduced backpressure across the entire exhaust path.
Does the S-PO991TSO-HT work with the Porsche PASM active exhaust system?Yes. The Akrapovic S-PO991TSO-HT is designed to integrate with the Porsche 911 Turbo's factory active exhaust valve control system. The electronic valve operation and its associated drive modes continue to function normally with the Akrapovic slip-on installed.
What is the Akrapovic Sound Kit and do I need it?The Akrapovic Sound Kit is an optional add-on that allows you to control the exhaust valves independently of the Porsche drive modes, giving you the ability to open or close the valves to your preference at any time. It is not required for the S-PO991TSO-HT to function; the exhaust works fully with the factory valve system without the Sound Kit.
Will there be any drone at highway speeds with the S-PO991TSO-HT?Akrapovic's engineering team specifically tuned the S-PO991TSO-HT to eliminate drone at highway cruise speeds. The system is designed to produce its deep, sporty character under acceleration and throttle input while remaining civilized during steady-state highway driving.
Does the S-PO991TSO-HT affect the Porsche factory warranty?Aftermarket exhaust components can potentially affect warranty coverage on related powertrain systems. Porsche dealers vary in their interpretation of warranty claims involving modified exhaust systems. We recommend consulting your dealer before installation if powertrain warranty coverage is a concern.
Are there any power gains with a Slip-On exhaust on the 991 Turbo?A slip-on system primarily improves sound character and reduces weight. Measurable power gains from a muffler-only replacement on a turbocharged engine are typically modest compared to a full cat-back or headers-back system. The primary benefits of the S-PO991TSO-HT are the weight reduction and improved exhaust note rather than outright peak power gains.
How difficult is installation for the Akrapovic S-PO991TSO-HT?The S-PO991TSO-HT is a bolt-on replacement for the OEM muffler section and does not require cutting or welding. However, the 911 Turbo's rear-engine layout requires careful access to the exhaust connections, and professional installation is recommended to ensure correct gasket seating, proper hanger alignment, and elimination of any contact with surrounding components.
What makes the carbon titanium tips unique on this system?Carbon titanium tips combine a carbon fiber outer shell with titanium inner construction, providing extreme heat resistance at the exhaust outlet while offering the visual prestige of exposed carbon fiber weave. This combination is lighter than all-stainless tips and adds a race-inspired aesthetic that pairs naturally with the 991 Turbo's performance character.
Installation Overview
- Allow the factory exhaust system to cool completely before beginning any work.
- Raise and safely support the vehicle on a lift or jack stands, chocking the wheels and engaging the parking brake.
- Apply penetrating lubricant to all OEM muffler fasteners and hangers and allow to soak for 15 minutes.
- Disconnect the OEM muffler at the mid-pipe connection flange, carefully noting the gasket condition and flange mating surfaces.
- Release all factory rubber exhaust hangers and lower the OEM muffler section from the vehicle.
- Clean the flange mating surfaces and install the supplied gasket.
- Position the Akrapovic S-PO991TSO-HT slip-on assembly and connect it to the mid-pipe flange, hand-tightening the clamp only at this stage.
- Attach all rubber hangers to their mounting pegs and verify the system hangs without contact with any chassis, suspension, or body components.
- Torque the flange hardware to the specification in the included Akrapovic installation sheet, working progressively and evenly.
- Start the engine and check all connection points for exhaust leaks. Re-torque after the first full heat cycle once the system has cooled.
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