Ok, as title states, just wondering how hard it would be. Couple of us on my car club are looking at getting a 83 RX7 we found cheap in town, and a friend has a NA 13b from his 3rd gen (he swapped to a jdm motor), and just wondering how hard and how much it would run to swap them. We're not new to cars, swapping motors or wiring, just never messed with rotaries(the guy with the 13b isn't on the club). Any help's appreciated.

 

there is no such thing as an n/a third gen. I believe that you need the GSL-SE crossmember to put a 13b in a 12a chassis

 

Yea, it must be a 2nd gen. I've never seen the car itself of his, he hasn't gotten it running yet. But anyway, what about ecu, wiring harness and the like? Also, after looking at the aftermarket and relative cheap prices for 12a engine parts, should we just keep it in there for autocrossing?

 

12a's do fine for autocrossing. your time and money would be better spent on suspension, braking and steering. At least initially.
There is much information on here about swapping a 13b into a first gen, do a search and you'll learn at least the basics.

 

You do not need the crossmember to install the 13b. You need a Se front cover and oil pan. Then you can either just bend the front mound forward or modify mounts.

Xotic, welcome to the forum. Yes this question has been asked to death. At the top of the page is a Search function, It's alittle hard at times to find a direct link to this but limit the amount of words used to narrow it down.

If you are not in a emission testing area or are not going to drive the vehicle on the street then it would be quite straight forward putting in a 13B. Meaning that you just run a carb.

But as fas as installing the ECU and wiring harness. If you have done other swaps in other vehicles then it's no different. Being a Rotary has nothing to do with anything until you get into the rebuilding of the motor. A wiring diagram is a wiring diagram, A ecu is a , get the point.