Performance Exhausts & Accessories
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About Us
ECU Tune
ECU Tune
987.1 Exhaust
987.2 Exhaust
987.1 & 997.2 ECU Tune
ECU Tune
GT40 Exhaust
2011+ Mustang GT 5.0 Exhaust
Ford GT
ECU Tunes/Flashes
About SpeedTech
02 Bung Extenders
Porsche Logo Carpet
Clamps / fasteners
Parts / Accessories
997.1 Exhaust
997.2 Exhaust
997 GT3 Exhaust
ECU Tune / Flash
Porsche 991.1 & 991.2 Twin Turbo X-cellerator X-Pipe
Exhaust System (2013+)
The SpeedTech X-cellerator X-Pipe or X-Flow exhaust is designed to offer the discerning Porsche enthusiast the ultimate exhaust system with a number of performance, sound and fitment options in one complete plug and play package.

X-FLOW DESIGN - By combining the exhaust pulses from both sides of the Porsche boxer motor with our proprietary "X" or "cross-flow" at the center of the exhaust, we have developed a unique, exotic sound that has to be heard to be appreciated. Our engineered trademark sound is well known and highly respected throughout the industry.

OPTIONS - The SpeedTech X-cellerator system offers a choice of German HJS catalytic converters, re-using the OEM catalytic converters or cat bypass pipes for track use, resulting in several possible exhaust configurations. Furthermore, there is a choice of re-using the OEM tips or utilizing our 3" dual tips and opting for the new VARI-CAT (variable technology, so the same Hi-Flow cat can be used for either the OEM muffler or any full x-cellerator system). The VARI-CAT lets the customer grow from a high flow cat with the OEM muffler to any other system we offer, utilizing the same cats.

Want to keep the OEM catalytic converters? This system is available as a center muffler replacement only with our OEM cat adapters, using the OEM catalytic converters for factory emissions compliance.

The modular design incorporates accuseal clamps for quick
and easy installation and component swaps.

PERFORMANCE - Our free flowing X-Design design, along with Hi-Flow German HJS catalytic converters or cat bypass pipes will improve the performance of your Porsche 991TT by enabling extremely quick turbo spool, along with increased torque, higher horsepower and much crisper throttle response! Faster track and ¼ mile times, better everyday performance and the pronounced engine note will provide an enhanced driving experience for all types of uses. Additionally, the SpeedTech X-cellerator system eliminates approximately 20 pounds of weight compared to the Porsche OEM exhaust. Additional weight savings can be realized with use of the off road RACE configurations.

IMPORTANT NOTE: If you start with our X-Pipe for OEM cats and/or OEM tips and you later decide to upgrade to the full 3" system, HJS cats or both, there is no need to buy an additional system. All upgrades are plug and play compatible, allowing planned economical upgrading.

Complete T304 stainless steel construction. This is a very well built, top of the line exhaust system for the discriminating enthusiast and very fitting for the top of the line Porsche turbo.

SOUND - The SpeedTech X-cellerator X-Flow exhaust emits a fantastic GT3 type note. We offer several distinct sound levels to suit a variety of tastes and uses:

We offer a lifetime warranty of manufacturing defects for the
original owner. The SpeedTech X-cellerator is designed, tested and manufactured in the USA .


991.1 & 991.2 Turbo Competition X-Pipe Exhaust Systems
Add a Softronic Tune!
991TT L6 3.0 X-Pipe Exhaust
991TT L5 3.0 X-Pipe w/ OEM Cats From Rear
991TT L5 3.0 X-Pipe w/ OEM Cats & OEM Tips
991TT L6 Launch Control Airstrip
981 Exhaust
ECU Tune / Flash

 It is one of the best exhausts I've ever heard. Speedtech nailed it with this one. It's very exotic sounding and plenty of snap, crackle and pop! Steve B.

HJS 130mm x100 or 200cpi Variable Technology Catalytic Converters for OEM Center Muffler or and SpeedTech System
HJS 130mm x 200cpi FULL 3"
Directional Catalytic Converters
FULL 3" RACE Cat Bypass Pipes
Tel: (603) 225-4600
Fax: (603) 228-4604
991.1 Exhaust
991.2 Exhaust
991.2 GT3/GT3 RS
ECU Tune / Flash
3.0 Titanium XP
ECU Tune / Flash
Turbo Inlet Pipes
3.0 Titanium XP
ECU Tune / Flash
3.0 Titainium XP
ECU Tune
Mesh Grills
Fresh Air Intake Plenum & Turbo Inlet Pipes
Clutch Upgrades
GT2 Clutch Conversion
75mm Throttle Body / IPD Plenum Upgrades
Fuel Injectors
Titanium 3.0
ECU Tune / Flash
Our 991TT X-Pipe replaces the OEM center muffler and provides a fantastic exotic sound - very fitting and tasteful for the 991TT. Available in both 2.5" Quiet, 2.5" Moderate and 3.0" Loud versions, our X-Pipe can mount directly to the OEM catalytic converters or can be used with SpeedTech 3" Hi Flow converters or bypass pipes. We include mounting straps, all hardware and installation instructions for a direct bolt on application. Our modular design enables ease of use for component swaps, adjustability and a quick, simple installation.

 SOUND LEVEL 1 (2.5 X-Pipe WITH Mufflers, re-use OEM Tips)

SOUND LEVEL 2 (2.5 X-Pipe WITH Mufflers and Full 3" Dual Tips)

 SOUND LEVEL 3 (2.5 X-Pipe/OEM Tips)

SOUND LEVEL 4 (2.5 X-Pipe w/Full 3" Dual Tips)

SOUND LEVEL 5 (3.0 X-Pipe/OEM Tips)

SOUND LEVEL 6 - MAX PERFORMANCE (3.0 X-Pipe w Full 3" Dual Tips)


“X-Flow” or “X-Pipe” designs vary and as a result, so does the sound characteristics. We tested several variations of the "X" design, with and without various mufflers, during the development of our SpeedTech Exhaust and at the conclusion of our testing, we determined the best parameters to achieve our signature sound - a refined, tuned, exotic tone with outstanding, highly desirable sound characteristics. All of our SpeedTech engineered X-Pipe exhaust systems provide a phenomenal exterior note combined with exceptional interior comfort /feedback and a substantial performance increase.

The extensive R&D we conduct to achieve our goals is reflected in the final product.

When you purchase a SpeedTech exhaust system, you are purchasing a one of a kind, superior sounding and performing exhaust designed and manufactured by long time Porsche enthusiasts and users of our fine products.

We strongly feel there is no better choice and we back it up with a sound guarantee (see our sound guarantee on this page).
As an entry level option for the 991TT or for those that wish to retain the OEM sound characteristics, we offer the modular designed Variable Catalytic Converter or VARI-CAT option, which allows the use of high performance HJS catalytic converters (either 100 cell or 200 cell) with the OEM muffler or with any other SpeedTech X-Pipe. By simply changing the V-Flanged outlet, the cat can be configured from the 65mm OEM outlet to a full 3" outlet for use with any SpeedTech X-Pipe. This allows the user to grow with the system or as taste changes, simply upgrade to the X-Pipe platform, while retaining existing cats.
OEM Muffler / Hi-Flow HJS Cat Option
VARI-CAT shown w/ both OEM & Full 3" Outlets
VARI-CAT w/ OEM Muffler
Alternatively, we also provide for the ability to use the OEM cats with any of our center muffler delete X-Pipes for those that may prefer to retain the factory emissions. This is accomplished by the use of our OEM cat adapters. X-Pipe systems that use the OEM adapter can be upgraded to any SpeedTech catalytic converter at any time should the desire arise. Our 991TT suite is fully plug and play for unlimited options with all SpeedTech cats, tips and X-Pipe sound levels!
OEM Cat Adapter for fit to any SpeedTech X-Pipe - Transitions from OEM cat to X-Pipe inlet
OEM Cat Adapter shown connected
from OEM cat to X-Pipe
SpeedTech R&D
Sound Guarantee
If you purchase any of our 996TT exhaust systems and wish to change the sound level, we will replace the center section with another one of your choice (i.e. 2.5 to 3.0, vice versa, muffler to X-Pipe, etc.) within 30 days of installation at no charge. Due to our modular design, all components on this are page plug & play with one another. On muffler delete to muffler XP swaps the delta is charged.

This is our way to help inusre that you are completely satisfied with your SpeedTech purchase!
OEM Tips installed on X-Pipe
Dual Tips
YouTube Video
991TT L3 2.5 X-Pipe w/ HJS Cats & OEM Tips
Download Video
991TT L1 2.5 X-Pipe w/ Mufflers, HJS Cats & OEM Tips
YouTube Video
991TT L1 2.5 X-Pipe w/ Mufflers, HJS Cats & OEM Tips
Download Video
991TT L3 2.5 X-Pipe w/ HJS Cats & OEM Tips