Normally aspirated Pro Modified cars commonly use what power adder?

Normally aspirated Pro Modified cars commonly use nitrous oxide as their power adder.

Nitrous oxide is injected into the engine along with additional fuel. It supplies extra oxygen during combustion, allowing the engine to burn more fuel and produce substantially more power without using a turbocharger or supercharger. In this context, “normally aspirated” describes the engine’s intake method before the nitrous system is activated; nitrous injection is still a power-adder system.

Pro Modified rules have historically permitted several combinations, including turbochargers, Roots-type superchargers, centrifugal superchargers, and nitrous systems. That means nitrous oxide is not the answer for every Pro Mod car, but it is the defining choice for the nitrous combination. Some sanctioning bodies even separate nitrous-powered cars into dedicated Pro Nitrous classes.

A common mix-up is calling nitrous “nitro.” Nitro usually refers to nitromethane, the fuel associated with Top Fuel dragsters and Funny Cars. Nitrous oxide is often shortened to “nitrous” or informally called NOS, after the Nitrous Oxide Systems brand.