Fabspeed's Performance Package for the Porsche 964 Carrera offers significant power increases in horsepower and torque by 35 whp and 34 ft-lbs. This dyno result DOES NOT include Fabspeed's DME software upgrade. For Fabspeed's Performance Package including the DME tune expect to see a greater increase in power.
Product Details:
Complete high-performance exhaust & intake solution for the 964 Carrera; includes Maxflo Performance Dual Outlet Muffler, European Pre-Muffler Catbypass Pipe, CUP High Performance Airbox, and a optional DME Chip.
 Experience a serious increase in horsepower and torque with this Porsche performance package designed for the 964 Carrera.  This kit will open up airflow, reduce weight, and optimize your machine’s systems for a smooth but aggressive delivery of power. With this package installed, we gained 35 horsepower and 34 ft/lbs of torque compared to the stock components.  Select whether you’d like the DME chip to be upgraded from the drop down above as well as which outlet type you would prefer - single or dual outlet. 
Each piece of this package is designed to be a direct replacement for the original part it replaces. The CUP Airbox Cover is a simple replacement for the front cover of the OEM part, and will drastically improve airflow to the engine. The Maxflo Muffler and Pre-Muffler Catbypass Pipe are all simple bolt-on upgrades that require no adapters, welding, or cutting. 
Includes:
964 Carrera Maxflo Dual-Outlet Muffler
964 Carrera European Pre-Muffler Catbypass Pipe
964 Carrera CUP High Performance Airbox
964 Carrera DME Chip
Features:
Fits all Porsche 964 C2, C4, RS America, Euro RS and Speedster vehicles 1989-1994
Increases horsepower and torque by 35 whp and 34 ft-lbs without use of DME, expect a greater increase with addition of DME Chip.
Constructed from high-quality, 14-16 gauge T304 stainless steel C.N.C. mandrel bent tubing.
Single or Dual Outlet muffler in one innovative system. Single outlet variant includes block-off for driver side outlet.
Euro pre-muffler catbypass pipe includes all the hardware and gaskets to bolt to the OEM heat exchangers.
Direct replacement for the restrictive OEM muffler and catalytic converter.
02 sensor bung so your 964 fuel injection system can automatically adjust mixture/idle/part throttle for maximum performance.
CUP airbox is a direct replacement for the front cover of the OEM airbox and will improve airflow into the engine.
Works with factory filter element or any performance filters designed to use the stock airbox
Simple bolt-on installation
Dramatically improved throttle response and overall increase in power throughout the RPM range
All Fabspeed performance products are backed by the Fabspeed Lifetime Limited Warranty
NOTE: Requires slight modification to the factory rear bumper for proper fitment of the second outlet