Quote:
Originally Posted by upflying
Why does the generation 5 Chevrolet Camaro SS equipped with a 426 hp LS3 have more horsepower than a 1970 Chevelle SS454 equipped with a 450 hp LS6?
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Because the rating of horsepower changed..ie:
SAE Gross Power
Prior to the 1972 model year, American automakers rated and advertised their engines in brake horsepower (bhp). SAE gross hp was measured using a stock test engine, generally running with few belt-driven accessories, under an ideal environment.
SAE Certified Power
In 2005, the SAE introduced "SAE Certified Power". To attain certification the test must follow the SAE standard in question, take place in a certified facility and be witnessed by an SAE approved third party.
The first engine certified under the new program was the 7.0 L LS7 used in the 2006 Chevrolet Corvette Z06. Certified power rose slightly from 500 to 505 hp. This certification reflects a more accurate rating,as built and as used.
This would explain the HP increase in the 6 cyl. when it was Cetified, gained horsepower rating in 11 vs 10.