Well race gas is generaly just leaded high octane petrol, running it in any engine won't harm it at all. Infact you may get a bit of extra power depending on the engine and fuel mix.
But what it can harm is the catylitic converters. The Lead in the fuel will rapidly clog the fine honey combe structure on the converter which of course is a bad thing.
If you dont have cats and its legal to run race gas and you can afford it then go for it.
But here in NZ its illegal to run race or aviation fuel in your car on the road because its leaded. (race gas is often made from old expired av gas, which as far as I know is still leaded, and will remain so for sometime as most planes require it)