The following Stock/Super Stock horsepower changes were released December 21, 2018 produced by the Automatic Horsepower Factoring System (AHFS). This is the second of two scheduled horsepower adjustments for this year. All changes are effective January 1, 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 national 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, AHFS@nhra.com or pcvengros@nhra.com

 

 

Stock Horsepower Changes

Complete for 2^nd half rating period of 2018

 

 

 

Engine                     OEM           NHRA       New

Make           CID      HP             HP            HP            Years Affected

 

Chev            327       275             274           278           1966 Nova

 

Chev            346       350             345           350           00-04 Corvette

 

Chev            350       530             602           610           14-15 COPO

 

Chev            350       590             616           630           17-18 COPO

 

Chev            376       365             365           370           2015 Camaro

 

Chev            396       325             320           324           66-68 Chevelle

 

Chev            402       375             405           415           1970 Nova

 

Chev            427       470             470           481           16-18 COPO

 

Mopar           135       146             155           157           1988 Sundance

 

Mopar           383       325-330      281           285           65-67 Belvedere

 

Ford             302       133             155           159           1978 Mustang

 

Ford             302       139             146           150           1978 Fairmont

 

Ford             302       150             197           200           1986 Thunderbird

 

Ford             302       350             388           393           2013 Cobra Jet

 

Pont             400       330             325           330           1968 Firebird

 

 

 

 

 

 

Super Stock Horsepower Changes

Complete for 2^nd half rating period of 2018

 

 

Engine                     OEM           NHRA      

Make           CID      HP             HP            New HP   Years Affected

 

Chev            327       250             250           254           1962 GT FWD

 

GM               350       210-225      285           289           1987 GT FWD

 

Ford             140       145             165           168           1984 Mustang

 

Ford             331       510             510           517           2012 GT RWD

 

Ford             429       455             455           461           2014 Cobra Jet

 

Super Stock Index Changes

Class           Old Index             New Index

 

SS/TB        9.95                   9.90