The Nuclear Propulsion Package (NPP) option is a vacuum controlled valve on the factory exhaust which is controlled by the ECU. It will open and close based on RPM and throttle position.
The valves will be open for the first two seconds that the car is started. It requires time for the vacuum pressure to build to close the valves. After that The operation of the NPP is normally closed, open on demand. Have someone stand behind the car and bring up the RPM to 3,500 and you should see the valves open. The butterfly operation is tied to the throttle position sensor and the RPM. It uses the throttle position to determine driver intent. Under normal operation the valves work as follows:
Below 30% throttle and 3,500 rpm the valves are closed. Above 30% throttle and 3,500 rpm the valves will open. Between 30% throttle and 80% throttle and above 3,500 rpm the valves are open. Above 80% throttle and above 2,800 rpm the valves are open.
Dual Mode Exhaust is a feature that allows your Camaro to stay within 'driveby noise' compliance. At 3500 RPM the valves auto bypass the factory mufflers to form a temporary straight back system which allows increased airflow at higher speeds.
The Borla "Cat Back™" name implies the exhaust system is located behind the factory catalytic converter where there factory emissions remain untouched and vehicle stays emissions compliant. This remains distinct from theAxle Back exhaust systemthat is located behind the rear axle. Alex Borla coined the phrase 'Cat Back' and introduced the Cat Back performance exhaust in 1978, a bolt-onreplacement performance exhaust systemrequiring no welding, thus being secured using the factory hanger locations.
Borla Cat Back exhaust systems use engine-specific (not universal) mufflers that are designed, tested, and optimized specifically for a particular year/make/model vehicle. Borla Cat Back systems increase the overall sound level & performance.
Vehicles that don't have a factory service-point require "cutting" the factory exhaust system before installing a Borla Cat Back performance exhaust system. Borla includes instructions where to make this cut and includes the hardware to complete the installation.
Many of today's modern vehicles have a factory service-point in the exhaust system (flange or slip-fit) located in the exhaust tubing behind the catalytic converter. A Borla Cat Back performance exhaust system replaces the factory exhaust system (behind this service-point) following the same exhaust path and secured using the original vehicle hangars and rubber isolators.
Borla pioneered the automotive exhaust aftermarket in exhausts constructed in aircraft grade 304 stainless steel tubing, a material with higher content of carbon & nickel that won't rust or corrode.