July 18, 2025

The Tech Department has issued a list of frequently asked questions and answers on the subject of modifications in SS/AH. As with any category, racers in SS/AH are constantly looking at smaller and smaller details in their quest for performance, necessitating periodic clarifications or interpretations of the text contained in the NHRA Rulebook. Input from NHRA Technical Inspectors, engine builders, competitors and manufacturers was used to determine the correct and current answers to these frequently asked questions, and to better clarify NHRA’s position on what is and what is not acceptable. The following information pertains to SS/AH ONLY. For questions and answers on other classes or categories, consult the 2025 NHRA Rulebook or contact NHRA Technical Services headquarters.

1. Can I have Removable or modified inner fenders? NO

 2. Can I use velocity stacks? NO

3.  Can I use oversized air pans with a ramp/diverter? NO

4.  Can the carburetor orientation be reversed? NO

5. Are titanium valves permitted? NO