The following Stock/Super Stock horsepower changes were released June 26, 2019 produced by the Automatic Horsepower Factoring System (AHFS). This is the first of two scheduled horsepower adjustments for this year. All changes are effective June 26, 2019. 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.
Stock Horsepower Changes
Complete for 1st half rating period of 2019
Engine OEM NHRA New
Make CID HP HP HP Years Affected Transmission
AMC 258 110 150 152 1979 Pacer A/T
Dodge 360 210 271 275 1980 D-150 A/T
Dodge 370 340 360 369 2009 Challenger A/T
Dodge 370 340 360 369 2010 Challenger A/T
Dodge 135 146 160 164 1986 Omni M/T
Ford 302 140 143 145 1979 Fairmont M/T
Ford 302 350 385 390 2014 Cobra Jet A/T
Ford 330 510 510 522 2012 Cobra Jet A/T
Pont 400 185 275 282 1975 Firebird A/T
M/T – Manual Transmission
A/T – Automatic Transmission
Super Stock Horsepower Changes
Complete for 1st half rating period of 2019
Engine OEM NHRA
Make CID HP HP New HP Years Affected Transmission
Chev 350 230 270 277 1988 GT FWD A/T
Pont 350 225 270 277 1988 GT FWD A/T
Chev 350 230 270 277 1989 GT FWD A/T
Pont 350 230 270 277 1989 GT FWD A/T
Chev 350 247 289 293 1990 GT RWD A/T
Chev 350 250 289 293 1990 GT RWD A/T
Chev 350 247 289 293 1991 GT RWD A/T
Chev 454 425 435 445 1971 GT FWD A/T
Chev 350 590 590 598 2017 COPO A/T
Chev 350 590 590 598 2018 COPO A/T
Dodge 512 450 478 489 2011 Drag Pak A/T
Ford 302 575 583 597 2016 Cobra Jet A/T
A/T – Automatic Transmission