Ok, I think I really suck at this searching game because I can not seem to find anything I am looking for. I was told that I should use the 84-85 GSL-SE rotor housings and crossmembers to put a 13B into my '80 RX-7. Since I have gotten onto this site I notice a lot of just straight swaps. Now do you have customize your mounts for that or does it just bolt straight up?? Also, I hear all this stuff about the different series trannies, what do they come from??

 

Mazdatrix/Racing Beat sell a motor mount plate that allows you to bolt a 13B in to the 12A crossmember.

Alternatively you could slot the holes.

The only size difference between a 12A and a 13B is that the 13B is 20mm longer due to the 10mm wider rotors. Either the front has to go forward, or the back has to go rearward. Going back is harder because then the driveshaft might bottom out etc. so we go forward just like the factory did.

You'll also need a GSL-SE oil pan.

"series" is the series of car. you can only easily use '79-80 ("Series 1") trannies in your car. all the other ones have a different shifter placement that would require cutting the floor.

 

Would it be better to stick with the 12a then?? I want it to be a pretty quick car, not sure if I am going to turbo it. It will be mostly a daily driver and auto-xer. Also, how strong is the series one tranny?? Just trying to decide what to do. Thanks for the help.

 

I blew a diff before I blew my tranny. Don't put a super strong clutch on it and you'll be OK.

Whether you want to to 12A or 13B is up to you. Personally I'm against putting 13Bs in 1st-gens because it just seems wrong to have an engine that isn't so zingy. (Strangely I have no problems with boinger swaps, but the idea of a 13B in an SA just HURTS!) 12As can make the same power, they just have less torque so the RPM range has to be shifted higher.

 

What do you mean by zingy?? Also, what kind of money and bolts on's could I look at before going to the internals of a 12A.

 

The only thing that you actually NEED is the SE oil pan, and you can mount "almost" any 13B into your car. It all comes down to how much patience you have and how much hard work you're willing to do.

Like peejay said, the decision of 12A vs. 13B is totally yours and from what it sounds like you want from your car, I really don't think it matters which you choose, and therefore ... you may be happy just keeping the 12A. 13B's generally run roughly 30 HP more than 12A's for identical mods, but they are not that much of an advantage in "most" street applications if you know what to do with your 12A.

With that said, the oil pan is all you NEED to change, but if you can't or won't do the mods yourself, then the SE front cover (you can use the 12A front cover just have to modify the OMP lines) and mounting bracket are the other two things that will aid the swap. Then it's just choosing your intake and exhaust.

1

 

Act 1, Scene 5
[the diabolical one dons his black cape, picks up his bible, and slowly walks down the aisle where he rebukes the evils spoken by peejay ...]

bad peejay, bad! i rebuke your evil words ...

sorry, i couldn't resist ...

 

lol

i'm an all or nothing kinda guy. either build up a 12A which can make the same power as a 13B (just has to rev higher but it can do that because airflow through the ports is the same) and enjoy the 12A's freer-revving feel, or just go all the way and build up a nasty 289 or 302.

I'm the same way with "other cars"... I won't stand for a small-block in an older Ford when I know damn well that a 429 will fit in there