Hello, fellow Wankelers! (notice I did NOT say *******)

My old SA is running fine with its 12A, but I'm looking ahead to the need for speed.

In my area, there are a few JDM engine supply shops to choose from, so I can get pretty well anything easily enough.

I would like to know what the community thinks as far as which turbo engine is best (strongest, can make the most power, most reliable, most cost effective, etc etc)

12a T, 13b TII, 13b REW?

Not interested in 20B.

Please add some info to support your opinions.

Thank y'all kindly!

 

The only good option in my opinion is the 13b TII engine for your application.
The 12A would be like a needle in the haystack find.

and the 13b REW would require a shitload of modification to get into the car.

NOTE: JDM dealers like YOUR MONEY so they will say anything to get it.
Be prepared and ask to compression test the engine on the floor of their facility.If they do not allow that then Walk away OR expect that the engine you are getting will require a Rebuild.

Again it is rare to find an actually GOOD mechanically sound JDM rotary engine.

 

best ... has to be the last. it is my opinion that the REW is the best of the ones you put on your list. i will assume the "FC Turbo" is your way of referring to the S4 engines and "FC Turbo II" is your way of saying the S5s. is that accurate?

anyway, i really don't have anything bad to say about the others. they are what they are and ALL can be potent if you know what you're doing. putting it in a Gen I car, i would go with the S5 though. i think it's best suited for most people looking to do what you are.

oh, and listen to the advice on those JDM vendors.

 

Correct! Sorry for the noob terms, and thank you for the opinion.

If you don't mind, what in your opinion makes the REW better than the S4 or S5?

 

well, as i said, it's the last of the breed. if you figure about 6 years between the S4 13B-T and the REW, then whatever Mazda learned over the years and felt was okay for a car available for public consumption, was put in the REW.

if you're looking for bullet points, then as far as the engine itself is concerned, they made tweaks to the oiling, cooling (compression/ignition area), and port runners. on the subject of cooling, there is a great thread by Barry Bordes that discusses some of it.

the dowel area improvement carried over from the S5 13B-T. also, i remember the FD brochures also mentioned a coating on the rotors as well, but at this point, my guess is that's no longer relevant in the real world - only for discussion like these.

however, it has always been my opinion as well that half the guys that insisted on getting the Cosmo RE(W)s and the FD REWs a few years ago (before prices went back up) could have done just fine with Gen II engines, especially the S5s.