The following Stock/Super Stock horsepower changes were released July 14, 2015 produced by the Automatic Horsepower Factoring System (AHFS). This is the first of two scheduled horsepower adjustments for this year. All changes are effective July 14, 2015. It should be noted that these changes include only results produced by the AHFS, and do not include written letters or requests. Those changes are listed separately.
The AHFS is a program based on actual run data compiled from all available runs at NHRA events. The data-based format provides the ability to calculate average performances for any class and/or engine combination in Stock and Super Stock. The trigger point for the system is 1.00-second or more under the respective index, and must be produced on two different occasions. Engine-combination averages and class averages are then computed and analyzed to determine if a change is warranted. The amount of change is calculated on a stepped percentage basis. Where applicable, adjustments will be effective for the specific car model or body style being evaluated. An automatic adjustment is instituted outside the two-time a year process when a 1.20 and under run is recorded during any NHRA event.
Any comments, thoughts, or requests must be sent in writing to: National Hot Rod Association; Technical Department; attn: AHFS; P.O. Box 5555, Glendora, CA 91740; or e-mail, http://www.nhraracer.com/ahfs.asp.
Stock Horsepower Changes
Complete for 1st half rating period of 2015
Engine OEM NHRA New
Make CID HP HP HP Years Affected
Buick 350 195 264 268 1972 Skylark
Cadi 350 180 186 189 1977 Deville
GM 231 200 200 203 95-02 Cam/Fire
GM 305 185-190 241 245 1987 Cam/Fire
GM 350 275-285 340 345 93-98 Cam/Fire
Chev 350 295-300 286 290 67-70 Cam/Nova
Chev 350 530 555 562 14-15 COPO
GM 350 245 268 272 90-92 Cam/Fire
Chev 396 325 325 330 67-69 Camaro
Chev 396 390 399 404 13-15 COPO
Ford 140 100 130 133 1980 Mustang
Ford 302 122 129 132 1975 Maverick
Ford 302 139 159 163 1978 Mustang
Ford 302 500 549 562 2013 Cobra Jet
Ford 302 525 550 563 2014 Cobra Jet
Ford 330 435 490 497 2010 Cobra Jet
Ford 330 425 512 519 2008 Cobra Jet
Ford 330 450 528 535 2012 Cobra Jet
Super Stock Horsepower Changes
Complete for 1st half rating period of 2015
Engine OEM NHRA
Make CID HP HP New HP Years Affected
Cadi 350 170 200 203 1978 SS/GT
Chev 265 180 197 202 1955 150
GM 305 145-155 256 260 82-84 GT FWD
Dodge 426 460 460 466 2015 Drag Pak
Ford 281 510 510 517 2008 Mustang
Ford 330 425 482 493 2008 Cobra Jet
Ford 330 450 527 539 2012 Cobra Jet
Ford 330 510 602 610 2012 Cobra Jet