Engine family average for the specific engine combination being reviewed. All cars, regardless of class, running the particular engine combination being reviewed are included in this screening.

Class average in the class utilizing the specific engine being analyzed. The class/engine average of the specific combination in the class that triggered the review is studied.

Body style of the engine combination being reviewed. Adjustments are only in effect for the specific car model being evaluated. However, in many instances the body style is classified by the OEM auto manufacturers' definition of "platform;" i.e., the Camaro and Firebird body are both based on the same platform and therefore considered the same with regard to body-style classification. In some instances, more than one body style will trigger a review.

The screening phase of the horsepower review is a rather laborious operation and must be done manually because no program exists that can differentiate and/or recognize a specific combination from the varying possible classes, engines, and body styles. As one Stock racer noted, it took six hours to gather the data required for him to personally review his specific combination.

To more clearly illustrate how the AHFS program affects a given combination, the following is an evaluation in Stock for the 305-cubic-inch, 215/241-horsepower, fuel-injected Camaro during races 16 through 23 in 2002:

Two K/SA Camaros running this combination ran 1.214- and 1.187- second under the index, triggering a review by the committee. As per the procedure outlined above, the overall engine family average is analyzed first. Upon reviewing the engine family average made by the 305/215/241 FI combination, 10 runs had been recorded by Camaros (2 in K/SA and 8 in L/SA) with a total engine average of .945-second under. Because the overall engine average did not hit the required 1.00 under, the combination did not warrant a horsepower adjustment.

The next step, per the procedure outlined above, is a class/engine review. The class of the car that actually triggered the review was K/SA. The class review revealed that K/SA had a class/engine average for the combination in question of 1.201-second under, therefore surpassing the 1.00-second-under requirement and signaling a horsepower adjustment for all 305/215/241 FI Camaros.

An important element to note and one most often misunderstood by racers is that although a K/SA Camaro affected the change, the L/SA 305/215/241 FI Camaros that run this combination also received a horsepower adjustment. The reason is that a specific combination can run in more than one class based on NHRA rules; therefore, all cars with the specific engine combination and body style will be affected.

Once the need for an adjustment is determined, the Stock/Super Stock Horsepower Committee must determine how much horsepower needs to be implemented. The committee has devised a sliding-scale formula based on a percentage of horsepower rather than a set amount.

As noted by NHRA Stock/Super Stock horsepower analyst Curt LaShure, "If you take an H/FS car with a horsepower weight break of 27.5 pounds per horsepower versus A/SA at 8 pounds per horsepower and gave each only five horsepower, A/SA would get a bargain."

Horsepower percentage adjustments or index changes are as follows:

Under Index	Increase	Index Change
1.150-1.299	1.25%	-.05
1.300-1.399	2.25%	-.10
1.400-1.499	3.25%	-.15
1.500 or greater	3.25%	-.15 (immediate change)

Adjustments are rounded up to the nearest full horsepower even if the fraction is below 0.5 horsepower. As an example, 2.15 horsepower is rounded to 3 horsepower. The quickest run for the combination being reviewed is used to determine the adjustment percentage.

In 2002, the Stock/Super Stock Horsepower Committee began reviewing runs of 1.50-second or more under the index as soon as such runs were made. Runs at divisional events and National Opens are included in the 1.50-second-or-more-under analysis. This was done to better react to any out-of-line indexes or under-horsepower combinations. Therefore, at all such events, a 3.25 percent horsepower adjustment or index reduction will be initiated immediately. The decision to adjust horsepower or to reduce the index will be at the discretion of the Stock/Super Stock Horsepower Committee.