NHRA News: Stock, Super Stock Horsepower and Index Adjustments Released (12/11/2000)

Stock, Super Stock Horsepower and Index Adjustments Released

12/11/2000

As announced last week, and after extensive racer input, the Automatic Horsepower Factoring System (AHFS) has been finalized for the 2001 NHRA Drag Racing season. The primary suggestion made by racers was to change the proposed 1.25 under the index allowance factor to 1.15 under. Therefore, effective Jan. 1, 2001, runs of 1.15 or more under the index will now trigger an evaluation rather than the proposed 1.25 number.

To recap the system as described in Issue 47 of National DRAGSTER: Only national event final qualifying data is included in the database. Any run of 1.15 seconds or more under index, or .25-second or less under index, automatically triggers a flag for analysis. Engine combination averages and class averages are then computed and analyzed to determine if any change is warranted. If the engine family or class average is 1.00-second or more under index an increase is initiated. If the engine family or class average is .50-second or less under index a decrease is initiated. The amount of change is calculated on a stepped percentage basis. Adjustments will be effective for the specific car model or body style being evaluated.

As a first step in implementing the new system, NHRA Tech officials reviewed the past year's data base and produced the horsepower and index adjustments as listed below. Although several of the adjustments are significant, the 1.25-under number was used as a base line in analyzing the 2000 data to phase in the new system.

"This has been a project that will prove well worth the effort," said Len Imbrogno, director of sportsman racing and member tracks. "Once everyone gets comfortable with how the data is anayzed and automatic changes are calculated, the racers will pretty much control their own destiny in terms of horsepower and index changes."

Two examples of how the system works can be found in the index change for T/SA, and the hp decrease for a 273 Chrysler engine in Stock Eliminator. Database analysis indicated an average of 1.17 seconds under for the 220hp/283 in T/SA, but only .36-second under in R/SA. A lowering of the index in T/SA, rather than an increase in hp is initiated, but at the same time, the Chrysler 180hp/273 is carrying an average of only .14 seconds under in T/SA already. So in conjunction with a lowering of the T/SA index, a decrease of 10hp for the 273 is applied at the same time.

"All of these changes are the result of data base analysis," said Imbrogno. "Although every letter and request from racers was reviewed, the new system should hopefully eliminate the need for racers to request adjustments. Interestingly, many of the combinations that received a horsepower decrease do have letters on file, which points out how effective the system will be." With regards to combinations that are not currently being used in competition, the Tech Department will still analyze engine blueprint specs and make subjective decisions.

"The entire NHRA tech department, as well as NHRA President Tom Compton, would like to thank all the contributing racers for their input. We welcome continued racer input regarding the new system, or any other thoughts and ideas racers may have about Stock, Super Stock racing. These categories play a very important role in the continued growth of NHRA Sportsman Drag Racing," said Imbrogno.

The changes take effect Jan. 1, 2001. The next schedule changes will be effective May 21, 2001.

Super Stock Index changes

Current Index New Index

SS/D 10.45 10.50

SS/G 10.70 10.75

SS/H 10.75 10.80

SS/I 10.75 10.85

SS/BX 10.70 10.85

SS/DX 9.60 9.50

SS/CC 13.10 13.25

SS/EM 10.40 10.50

SS/TA 10.00 10.15

SS/TB 10.10 10.20

Horsepower changes

1980 to 92- Dodge Truck Engines- 360ci- add 25hp

Factory Ratings 170,175,180,190,205,210 change to 285 HP

1974,75,76 Chevrolet- 400ci- 175,280 in GT- add 20hp

change to 300 HP GT only

1983,84,85 Olds- 307ci- 140 in GT- add 7hp

change to 227 HP GT only

Stock Index changes

Current Index New Index

AT/S 13.00 12.70

BT/S 13.15 13.05

CT/S 13.15 12.70

DT/S 13.35 13.05

ET/S 13.55 13.35

FT/S 13.70 13.60

AT/SA 13.05 12.80

BT/SA 13.20 13.15

CT/SA 13.35 13.05

DT/SA 13.50 13.15

ET/SA 13.55 13.35

FT/SA 13.75 13.65

AF/S 14.85 14.65

GF/S 17.00 16.75

AF/SA 15.05 14.65

BF/SA 15.25 14.95

FF/SA 16.25 16.00

GF/SA 17.45 17.20

T/SA 14.80 14.70

Horsepower changes (Increases)

1977,78 Pont- 400ci- add 7hp

Factory rating 180 change to 272 HP

1974 Pont- 350ci- add 9hp

Factory ratings 170, 200 change to 269 HP

1979,80,81 Chev-305ci- Add 10hp

Factory ratings 155, 160, 180
Malibu coupe 2dr only change to 245 HP

1973 Ford- 351ci- add 15hp

Factory rating 266
Mustang only change to 300 HP

1985 Chev- 262ci- add 10hp

Factory rating 130
Monte Carlo only change to 160 HP

1993,94 Ford- 302ci- add 5hp

Factory rating 235
Mustang only change to 245 HP

1995 Ford-302ci- add 5hp

Factory rating 240
Mustang only change to 245 HP

Horsepower changes (Decreases)

1970 Olds- 455ci- remove 10hp

Factory ratings 365, 370 change to 365 HP

1964,65,66,67 Chry, Dodge, Ply- 273ci- remove 10hp

Factory rating 180 change to 165 HP

1978 Chry, Dodge, Ply- 360ci- remove 10hp

Factory rating 150 change to 230 HP

1972 Pont- 455ci- remove 10hp

Factory rating 300- change to 335 HP

1971 Olds-455ci- remove 10hp

Factory rating 340- change to 335 HP

1982 Ford- 97ci- remove 3hp

Factory rating 70- change to 77 HP

1981 Ford- 97ci- remove 3hp

Factory rating 65- change to 77 HP

1979 AMC- 304ci- remove 5hp

Factory rating 125 - change to 190 HP

1969 Chev- 350ci- remove 5hp

Factory rating 250- change to 245 HP

1965 Dodge, Ply- 426ci- remove 10hp

Factory rating 365- change to 320 HP

1984 Ford- 140ci- remove 3hp

Factory rating 84- change to 87 HP

1989 Chev- 173ci- remove 5hp

Factory rating 125- change to 145 HP

1986 Chev- 173ci- remove 5hp

Factory rating 120- change to 145 HP

1988 Ford- 140ci- remove 3hp

Factory rating 90- change to 97 HP

1976 Ford- 140ci- remove 2hp

Factory rating 92- change to 113 HP

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