It's common knowledge that the Corvette, going back to the mid 2000s has offered an exhaust valve option (RPO: NPP). In 2014, when the Chevrolet Corvette Stingray (C7) arrived, it included dual mode exhaust valves as standard equipment, as well as a set of "AFM exhaust valves" to help reduce the odd exhaust notes when the engine runs in 4 cylinder mode. When the 6th Gen Chevrolet Camaro came along, the dual mode exhaust valves became standard equipment on the SS and ZL1, and optional equipment on the V6.
These exhaust valves are designed to stay closed during normal driving operation to meet federal noise standards, and essentially bypass the mufflers under hard acceleration for maximum performance. In Track mode, on the C7, the valves are designed to stay open all the time.
The exhaust valves are controlled by the same ECU that controls the fuel pump pressure on the Chevrolet Cruze and Chevrolet Sonic. In fact, we found that the Camaro SS CCM is connector-compatible with the Cruze CCM! With a bit of wiring, and some software work in the CCM, retro-fitting exhaust valves on the Cruze / Sonic might be possible.
Of course, the question is, how would one set up the exhaust valve? One idea we have is to T the single exhaust near the rear of the car into two pipes, one going through a standard muffler, and the other, through an exhaust valve, to a straight pipe out the back (or a cut out).
Just one of the innovative projects TRIFECTA has on the horizon for 2018!