The DOHC VTEC C30A is a 3.0 L version, producing 270 bhp (201.3 kW; 273.7 PS) and 210 lb·ft (285 N·m) of torque. The engine was the first to utilize Honda's proprietary VTEC variable-valve timing system in an automotive application, which adjusts cam lift and duration depending on engine RPM and throttle position. VTEC allows the C30A to produce a high maximum power level while maintaining a relatively flat torque curve.
The C30A also made use of titanium connecting rods, which was another first in a mass-production vehicle. The lightweight rods allowed a higher RPM to be achieved while maintaining the strength of traditional steel rods. The C30A block is an open-deck design made from an aluminum alloy with cylinders sleeved in ductile iron. The heads are a twenty-four valve, dual-overhead cam (DOHC) design and contain the VTEC mechanism, which is actuated by oil pressure. For maximum performance, the C30A uses a direct ignition system, with individual coils positioned directly over each cylinder spark plug.
Due to its DOHC layout and its lightweight rotating assembly, the C30A is capable of reliable high RPM operation. Factory redline is 8000 rpm and balanced/blueprinted versions of the engine can easily reach 9000 rpm with little to no reliability issues.
Due to its complexity, cost and use of exotic materials, the C30A was used exclusively on Honda's NSX car. For NSX's equipped with a 4-speed automatic transmission, Honda used a slightly less powerful version of the C30A, which utilized less aggressive cam timing and produced 252 bhp (188 kW; 255 PS).
An advanced version of this engine exists (though not in a production form) that campaigned briefly in the 2004 Japanese SuperGT racing series (see All Japan Grand Touring Car Championship) by the factory-supported Team Honda Racing group in highly modified GT-spec NSXs. This engine has various upgrades and modifications by Mugen and is the first turbo-charged Honda engine used in the series (prior to 2003, the GT-spec NSXs used a highly advanced, naturally aspirated variant of the C32B engine). Though the exact performance figures are kept secret, it is rumored to output more than 500 bhp.
- 1991-1996 Honda NSX 5-Speed Manual Transmission
- 1991-2005 Honda NSX 4-Speed Automatic Transmission
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