Hi all, I have a first gen 12a. I've been ready to buy and build a 13b but waiting till I come across one locally, which can take a while. The plan is to turbo the 13b, but since I've been waiting for about 6 months, I'm wondering if it's possible to get a turbo for the 12a for now, and then put it on the 13b once I get one and build it? A stand alone is being added now for immediate use and future 13b swap.

If possible, is this a bad or expensive idea? I'll only consider it if doesn't cost that much more in the long run.

Thanks!

 

u lost me after ..if it doesn't cost that much ...

 

cost that much more, than just waiting till I build the 13b. Haven't had any luck finding one.

 

I've only had two turbo cars and neither is a rotary. But the 12a and 13b take different intake and exhaust manifolds that can't be mounted on the other motor (12a manifolds won't fit on 13b motors). So while the turbo itself could be moved to the new motor when you find it, you will need a new intake and turbo exhaust manifold for the swap. If the new exhaust mani connects to the rest of the 12a exhaust then that might be it. Just new manifolds, so maybe $500-800 for those when you put the 13b in..

 

What he said^

you really need to decide which way you are going to go at the start.
A built 12a turbo is pretty much as potent as any 13b.
but a full 13b (t2) swap might make more sense since it will be cheaper and easier and the path of least resistance with parts both oem and aftermarket.
im not sure if it translates to your neck of the woods but where i am a 12a engine in servicable condition will command a pretty penny due to NLA parts and demand among purists and/or specific racing divisions that want 12a only, so financially it might work out better to sell the 12a on once you have the other engine ready.

 

My bro-n-law drag races rotaries in the import scene and ALL the Puerto Rican guys want 12a's. They're held in higher regard, maybe because they're getting so rare. I don't know.

I'm getting ready to swap a 13b into my '85 and I went with an early style 4-port 13b, because I wanted it to be period correct (the S4 13b's weren't out yet). Not sure if I'll be selling the 12a or sitting on it to watch the prices go up. Or put it in my riding mower

 

^ i think its because the shorter e shaft and apex seals flex less and can be pushed harder in big boost, big rpm drag racing applications.
not that that is really a concern for most of us running less than insane power levels.

 

Thanks for the inputs. $500 "extra" might be the most I'm comfortable spending to swap the turbo from the 12a to the 13b. With that said, I love the 12a, only want a bit more power and think a turbo will make it more fun to drive. I'm not interested in building a ton of power. I drive It around town, taking the routes with a lot of turns when I can. It just seemed it'd cost more to build a custom turbo set-up on the 12 vs swapping a turbo ii. I also try to "be different" when I can.

As for the 12a, I promised I'd give to my brother for his wife's first gen that needs a motor. I might need to back out of that promise if I can get 1k+ for it lol.

 

My brother and his friends, including the mechanic, are RX7 enthusiasts. You should see the monster rx7s they all have. When I discuss turbo 12a, I'm met with "no, just go turbo ii" because they're all about power. I come here to get input so that I can get unbiased opinions.

 

Not entirely accurate.

You can re-drill 12A and 13B exhaust manifolds and flip flop them from one engine to another. When I bought my red car I didn't want to go turbo immediately so I used the 12A headers it came with. I did cut and weld the plates farther apart but If I had wanted to I coulda just drilled some holes in the exhaust plates. A few guys on here have re-drilled 13B headers for turbos to fit a 12A.

Intake's are almost the same situation. I run a Nikki manifold on my FC engines. You just need an adaptor plate to make the intake match.



I do agree with the "why 13B?" question. The difference between 12A and 13B is insignificant once you start boosting on them.