Sr20det is the engine that is in the japanese version of your car. It is intercooled, and turbo charged and makes 200hp bone stock. adjust hte boost a little higher and it makes 250hp. With some bolt on's can get up to around 400hp. Best of all it's cheap. Engine, trany and ecu can be bought for around 17-2200. Look on [ www.240sx.org ] for links on where to buy the engine. Alot of the members there have done this swap. On a light car like that you will blow away us NA z'ers and Run close with some tt's.
I use to have a 240, and my g-friend has had two. There great cars.