Power and torque certification provide a means for a manufacturer to assure a customer that the engine they purchase delivers the advertised performance. This SAE Standard has been written to provide manufacturers with a method of certifying the power of engines to SAE J1349® or SAE J1995®. Document SAE J2723 specifies the procedure to be used for a manufacturer to certify the net power and torque rating of a production engine according to SAE J1349® or the gross engine power of a production engine according to SAE J1995®. Manufacturers who advertise their engine power and torque ratings as Certified to SAE J1349® or SAE J1995® shall follow this procedure. Certification of engine power and torque to SAE J1349® or SAE J1995® is voluntary, however, this power certification process is mandatory for those advertising power ratings as "Certified to SAE J1349®".
SAE Engine Rating Standard Prevents Numbers Fudging (an article on how GM will use SAE J1349® Certified Power, AEI May 2005, Vol 113 No.5, p 59 )
General Motors has become the first manufacturer to certify an engine's power and torque ratings using a newly adopted SAE standard (J2723), James Queen, GM Vice President, Global Engineering, announced during his keynote address at the SAE World Congress and Exhibition in April 2005. The world's largest automaker plans to certify all of its engines to the voluntary standard, and is encouraging its competitors to do the same. The LS7 engine for the 2006 Chevrolet Corvette Z06 was certified under the new standard this month. The 7.0-L V8 unit produces 505 hp (377 kW) at 6300 rpm and 470 lboft (637 Nom) at 4800 rpm. "The new voluntary SAE power and torque certification procedure ensures fair, accurate ratings for horsepower and torque as it uses third-party certification," said Queen. "SAE technical standards level the playing field, and this certification procedure is just the latest example of the value SAE has offered over the past century." To tout power and torque ratings as "SAE-certified," engine manufacturers must have an SAE qualified witness watch over the entire testing procedure to ensure that it is conducted in conformity to SAE standard J1349®. Third-party witnessing is the main provision of J2723. An existing SAE standard, J1349®, spells out how the actual testing is to be done. J1349® was updated last year to eliminate some ambiguities that allowed engine makers to cite power and torque ratings higher than the engine's actual capabilities. Engine makers are free to cite power and torque figures drived from testing conducted outside the scope of the SAE standards, but they may not claim the figures are SAE-certifed. "We feel that both the consumer and industry are well served by having accurate, consistent ratings from all manufacturers," said David Lancaster, a Technical Fellow in GM Powertrain and Chairman of the SAE Engine Power Test Code Committee that updated J1349® and wrote J2723. Data from a wide array of parameters (e.g., air:fuel ratio) will be collected during testing conducted to the SAE standards. SAE will create a database and offer it to industry in different packages and at different price points.
By Patrick Ponticel