i was just wondering what people would think about this. i want to put a 3rd gen motor in my 81 gsl. if i got the engine with everything on it, should i get something like a haltech or wolf 3d management system to plug into the engine wiring, then match wires on the management system to my 81 wiring harness coming out of the firewall. will this work? or do i need a parts 3rd gen for wiring and the ecu.

 

nope

you arent even close

aint nothing gonna match trust me... You have to run all new wires. And your easier and cheaper swap would be a cosmo 13b. Even tho still your swap would be around $8,000

BTW: the motor will fit in the engine bay in stock form

 

[hijack]
And how much modification do you think would be required to get a renesis in there? I'd imagine it would take a lot of inginuity, and a bunch of custom-fab stuff, but I can't wait to see someone do it!
[/hijack]

 

You'll have to wait a while to get a factory Renesis and I 'd hate to see someone total their 8 so soon.

 

still waiting for Mazda to issue part numbers for their Renisi...

 

Where do you find a cosmo 13B? and were is the engine from? a cosmo?

 

Hence the name cosmo 13b.

 

allright thanks, wasnt sure if that was the only source for theese engines. Also (sorry to hijack the thread but) what is the difference between the cosmo 13b and the 13b from the rx7's ?

 

You want an easy 255-280 HP? Don't go twin turbo, do a single turbo setup minus everything that makes the 13B in the 3rd gens notorious for self destructing. A 13B is a 13B once it's stripped of everything. The older the motor the more bulletproof it is. The Cosmo 13B is an EXCELLENT choice.

 

The cosmo 13b is a 4 port and obviously carbed, whereas the rx-7 engines are 6 port (excluding the turbo engines).

 

There's a shitload of differences between the various 13B's. Port size, number of ports, type of apex seals used, compression, location of water seals, epitrochoid shape, oiling system, the list goes on. As for older motor's being more bulletproof, what exactly do you base that on?

 

No, they're talking about the JC Cosmo 13B-RE. It comes from the Jap only Eunos Cosmo's that also came out with the 20B.

 

The main difference between the cosmo 13B (JC Cosmo that is!) is in the fact that the Cosmo engine is more of a torque machine, while the FD engine was more of a rev-happy HP engine. Obviously, I'm putting things way simpler then they are here. But it's just to make clear that there's a difference in how the engine's were originally built. Even if I think there must be way more FD's then Cosmo JC's (13B ones) the Cosmo engine tends to be a whole lot cheaper. For a swap to first gen, it would be the obvious choice.
Nevertheless, as stated before, it will still cost a lot of money! The engine itself will be only the start. Basicly, any rotary from Mazda will fit rather easy under the hood of a first gen. You either modify the subframe or (easier) get some custom engine bracket (RB, or selfbuild). If you already start with a GSL-SE front subframe, it's really simple.
So fitting the engine in is the easy part. However, a modern engine is slightly more then an engine.
Assuming you use an FD engine, it'd be a wise choice to get an FD ECU, and as much wiring as possible. Then go ahead, and have some sleepless nights...
If you go with a Cosmo, I believe a aftermarket ECU would be best. The stock ECU has (as far as I know) a lot of different inputs from various things as A/C, P/S... Once you cut them off, it'll go to limp mode, as it can't reconize these "vital" organs. Obviously, Mike will know more about this, as he has some hands on experience
I you go aftermarket ECU, you'll have to convert the twin turbo's to non-sequential (if you don't go single turbo anyway). So there's a lot of work, and money involved, to get that thing running.
As for the Renesis... It will fit, as it's smaller then the last gen 13B's. But just imagine the work on the electronics. This engine has variable intake etc, it'll need a serious ECU. Unless of course, you throw that all off, and use a custom intake, with injectors ran by an aftermarket ECU. One question remains the endhousing. Up to now Mazda always used the same basic bolt pattern to attach the box to the engine, making swaps rather easy. I doubt they continue like that. All engines up to now where evolutions of the last one before, but the Renesis really is a new engine...

 

Once mazda releases the part numbers, you'll be able to buy one straight from them right? For an arm, a leg, and a couple internal organs I'd assume...

Jon

 

thank you so much, rotary emotions, for your answer. is there anywher ei oculd fin dout more info on the cosmo engine. more about the differences between it and the 13b-re used in the 3rd gens. and why is it cheaper?

 

The most inefficient, strongest rotary engine is one that runs without any emissions related components. A good cooling and oiling system will benefit it's longevity. Having a turbo(s) and having to pass stringent emissions regulations just don't mix. Imagine a single turbo emissions-less 13B in a 3rd gen. So much easier to work on and maintain. But it'll never happen. Maybe that's why the Renesis is N/A'ed. Mazda hopes to overcome the reliability issues of having a turbo'ed model.

 

where do i go about gettin a cosmo engine? o anywehre to get any mroe info on them??

 

dude check ebay and some of the engine importers sites... PedX

 

Well, basicly they are simular. Main difference is the intake runner length, and the port size. Maybe some other minor things, but the ports and runners are the main things.
I never really understood why they are cheaper. I mean: they all come from wrecks, and I can't imagine those Cosmo's being much more common then FD's in Japan... But they are cheaper, so you just aswell might get one of those instead of an Fd engine.
They are less powerfull, yet have more torque. Since installing a Cosmo or Fd engine in a first gen is a serious project anyway, you'll most likely end up with some extra HP anyway. After all: if you have to build a custom intake and exhaust, you might aswell do it correctly, don't you?
I'm not sure what the law would be like, but since you put it into an old car, you might be able to delete most of the emission control ****, and thus making the proces less complex.