Abstract: An exhaust chamber system having a rotatable propeller type blade assembly at the entry to an expansion chamber which creates a vortex that swirls exhaust gas towards the outlet. The resultant action within the exhaust chamber aids in scavenging internal combustion engine exhaust gases, and in reducing system back pressure. The exhaust chamber maintains the sound level of the exhaust within acceptable limits while delivering improved horsepower, torque, and/or fuel efficiency over other known conventional mufflers.

Abstract: Tamper-resistant features are provided for a vehicle hood-locking and ignition disabling apparatus which functions as an automotive anti-theft device. These tamper resistant features are responsive to efforts to defeat or by-pass the anti-theft device and comprise: 1. a magnetically-operated alarm; 2. a lock "breakaway" portion responsive to efforts to break or pull the lock portion of anti-theft device; and 3. an underhood dead latch assembly adapted to dead-bolt the hood of the vehicle in a closed position, and to latch the ignition-disabling circuitry in a closed position.