I was just wondering if there was a way to convert from 4-lug to 5-lug? Any ideas?

 

covered in the FQ i am sure. Easy swap, very straightforward.

 

Take the 5 lug, and put on the 4 lug car.

Done.

 

You simply swap everything all the way back to the hub and spindle. Bolt off, bolt on. A trip to the junkyard can get it cheap, although with a lot of rust to muscle through. People also sell swaps for $100-$200 ($200 I think unless you get a deal). Lucky 7 swapped mine for a little over $300, all parts except wheels included. Looks like they cleaned them up and resurfaced the rotors nicely too.

Search forums for more info, or it may be in the FAQ as said.

 

If all you want is the 4 piston calipers, this might be an option for you:
http://www.aaroncake.net/rx-7/4lug4potbrakes.htm