Hi, im nw here, but have a question, I want to keep my (not really mine, but my dads) '91 RX-7 Convertible Rotary, but also want to upgrade to a newer engine while keeping it NA, is there any particular engine that would meet my criteria? it is 100% stock right now, and the old engine is toast, and its been sitting for a few years, i cant remember what year the engine went, I was thinking about doing a Renesis swap, but if theres an engine that would be better suited for what im looking for.

 

The only newer NA rotary is the Renesis.

While not straightforward, it is much like any other engine swap in the sense that you just have to fabricate mounts, use the appropriate flywheel and clutch, then figure out a way to control it. Swapping the EFI system from the RX-8 is going to be a no-go, so you'll be looking at a standalone. Off hand I don't know which one will control the 3 stages of injection as well as the 3 port actuators needed. An entry level Motec would be the first thing I'd look at.

 

You could get the engine thats in the car rebuilt and get the intake and exahust ports ported to your choice, street port to p-ports, I cant spell the actual word for p-ports lol.

 

Thanks for the advice, another question tho, if I were to rebuild the engine what would be the best way for me to squeeze a little more juice out of the engine? maybe a 30-50HP increase

 

If you ported the exhaust and intake ports it would increase the horsepower decently, also once its rebuilt put a racing beat header and presilencer on it and youll have a pretty quick rx7

 

thank you for the help now i have a better idea of what im going to do to my RX-7

 

No problem, but definitely research about what I mentioned on this site because there are tons of things you can do to your engine during rebuild and simple bolt ons once its built that will add a good amount of power.

 

Without a lot of work, 50HP isn't really an option. 20-30HP is, with a decent port job, good exhaust and good tune (the stock tune is rich, pull out some fuel). The problem is, when you start opening up the exhaust on an NA rotary, it becomes very loud. It's rather obnoxious to be driving around a sub 200HP car that is louder than a 20,000HP jet dragster.

What you have to ask yourself, is it worth it? You'll be into $2000 to rebuild and port the engine, then another $1000 - $ 1300 for a nice exhaust. Then $500 for a way to control fuel (S-AFC) and a wideband. In my mind, 30HP isn't worth it.

 

Yeah thats true. That is the reason why I am considering selling everything thats N/A I own and starting a Turbo2 swap.