can i put racing fule in my 1996 volvo 850 na

Hello, You can safely use up to the highest recommended octane of fuel as is prescribed in the owners manual. Aside from that, the fuel may not destroy the engine, but know that the engine was designed for a less volatile fuel at the compression ratio it uses. Adding a higher octane of fuel will increase cylinder pressures, and can be detrimental.

Considering the additional cost of "racing" fuel ... Why do you desire to do so?