I have a 1980 280zx (10th anniversary) automatic l28. I want to swap the engine with something much faster. I'm new to the Z world so don't trash me for not knowing, I'm here to gather information as I try to research. But to keep it in perspective I would like to race this car as fast, if not faster than a rx8 Mazda or be able to easily challenge mustangs camaros and even 370zs. Any ideas? I'd like to keep it automatic because my younger sister needs to drive it as well and she refuses to learn manual

*EDIT*: I intend to keep the original engine as well. It's a rebuilt with no more than 3,00 miles on it so it's a no-brain-er to keep that.

Define "race". An S130 is not going to keep up with an RX8 on an autocross or road course even with a good lsd. On a drag strip yes it can be done, the cheapest route is the L28ET, the turbo motor that came with the 81-83 280ZX Turbo. An intercooler, bigger injectors, megasquirt, headstuds and MLS headgasket and you should be able to get low 13's. You can do crazy stuff like an Rb swap, LS swap and make more power, or even build the L28ET but getting it to bite and go is not easy with that rear suspension even with a good diff. Auto trans, well if you do the L28ET it bolts to your current trans, I'm not sure how long it will last when you put any power to it, most anyone who does any sort of racing with these does so with a manual trans. Plenty of guys with SBC swaps running auto.