If you're looking for pc racing sims, check out
simraceway. The game itself is free, but they would love to sell you their super nifty F1-looking
steering wheel. All the buttons and switches actually do stuff, and they can all be custom assigned.
Tie that to some pedals, pick up a cheap racing seat, build a simple frame to hold it all, and you're good to go. Make sure you wear your nomex gloves and driving helmet for the full effect.