POWERTRAIN
The cool air intake is incorporated into the styling
Mid-mounted engines present a
greater NVH challenge than front engines because their intakes are much closer to the vehicle occupants’ ears. The audible soundtrack can become a plus point for a sportscar but would be considered intrusive on a more mundane vehicle. Greater driver skill is necessary to
extract the most from a mid-engine chassis because the low inertia that makes the vehicle so responsive can, at the limit of adhesion, make the car rotate more quickly. This makes control and recovery more challenging and could lead to a spin. Though electronic aids can eliminate this issue nowadays, the manufacturer must calibrate the system carefully to avoid overly intrusive intervention that would blunt the inherent driving appeal of the mid-engine layout. One of the biggest challenges
is engineering the exhaust system. Compared to a front engine installation, the available length is much reduced yet the same level of aftertreatment and silencing is required to meet exhaust emissions legislation and drive-by noise requirements. This must be packaged without impairing the engine performance or generating excessive heat in the engine compartment. At the same time, a sportscar exhaust
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The optional performance exhaust
must also produce an appealing and distinctive sound; quite a tall order.
THE 2020 CORVETTE SYSTEMS Today’s high-performance exhaust systems use active valves to vary the system back pressure, producing the optimum balance of performance, sound characteristics and regulatory compliance. Tenneco Clean Air supplies two systems for the 2020 Corvette featuring either two or four electronic exhaust valves. The small block V8 LT2 engine with the standard exhaust develops 490bhp and 465lb-ft of torque; with the performance exhaust these figures increase to 495bhp and 470lb-ft,
enough to propel the car from 0-60 in under three seconds, according to GM. The standard exhaust has
two newly developed valves with enhanced heat resistance that work with the vehicle’s Active Fuel Management system, supporting the engine’s cylinder deactivation function for optimum efficiency and lower emissions. The optional performance exhaust uses two additional electronically controlled valves at the rear of exhaust system, where temperatures are lower, to deliver acoustic differentiation. The driver can select ‘stealth mode’ for cruising, ‘sport mode’ for more dynamic driving or ‘track mode’ for the full Corvette experience.
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