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rx8 heart in 91 rx7 na

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Old 12-08-11, 08:02 PM
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rx8 heart in 91 rx7 na

i own a 91 rx7 non turbo and i was thinkin of swapping in the engine of and rx8 and wanted to know if i needed to get different mounts,tranny, or just anythin? any advice will be greatly appreciated thank u
Old 12-08-11, 08:49 PM
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Yes. The mounts in the RX-7 and RX-8 are different. Your looking at some custom fabrication.
Old 12-08-11, 08:59 PM
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so i couldnt just buy different mounts i'd have to get them made? srry im a newbie
Old 12-08-11, 09:04 PM
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Quoted from the 2nd gen FAQ.

Can I put the RX-8 engine (Renesis) in the 2nd gen?
Well, technically yes. But it is not a simple bolt-in swap. The Renesis uses different mounts, and an entirely different ECU and wiring harness. Anything can be done, but this is much more complicated then swapping any 2nd gen engine into the car. Lots of fabrication, wiring and other things must be done to support this engine. It is generally easier (and probably cheaper) to swap in the 20B three rotor, or the 13B turbo from the Turbo II.

So pretty much, no.
Old 12-08-11, 09:09 PM
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oh ok thank u vary much tht was helpful i dont want to get into somethin to complicated so maybe ill go with the 20b now would i have to get mounts for tht too or anything
Old 12-08-11, 09:10 PM
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Originally Posted by RXSpeed16
So pretty much, no.
Your pretty much wrong.

Engine mounts would have to be fabricated. You need the Renesis, and the wiring harness, and the ECU. I am not sure if the transmission bell-housing was changed or not. But it is still basically a 13b so it could bolt to the T-II tranny if you used a T-II clutch and flywheel. You will probably have to fabricate your own mounts, I doubt anyone sells them.

Can it be done? Yes. It could. Is it worth it? No not really. How easy is it? Not easy. If you want more power go with a T-II, or some other engine swap that is easier and more documented.

To the Original Poster, your not gonna complete an engine swap unless you've got someone to hold your hand, or you learn to use google.

http://fc3spro.com/TECH/SWAP/COSMO/20b.html

These are not hondas, or even mitsus where engine swaps are somewhat common. Sure if your N/A its honda swap easy to go turbo. And yes there are bolt-in v-8 kits. Motor swaps are only common in the honda world because you can take a 2.2 and bolt in the engine bay of a 1.6 eg hatch gut it from the driver's seat back, and run 11s with good tires.

Last edited by Rotank; 12-08-11 at 09:23 PM.
Old 12-08-11, 11:15 PM
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I was paraphrasing the question about the swap in general. The OP's last question was answered in the text I posted. As for the 20b swap, it is definitely not a 'mount it where it fits, throw a carb on it, and take it to the dragstrip' operation. It is complicated and/or very expensive for someone new to rotaries. You can get a solid 13bt setup for 5k and save yourself 10k.
Old 12-09-11, 09:53 AM
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Originally Posted by Fcanchez
oh ok thank u vary much tht was helpful i dont want to get into somethin to complicated so maybe ill go with the 20b now would i have to get mounts for tht too or anything
As with the Renesis, a 20B swap means that everything must be fabricated.

The only engine that bolts directly in is from another 2nd gen.
Old 12-12-11, 06:22 PM
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I would definately not do that swap. If you are going to go through the trouble of swapping the motor, you should just put in a TII in it. It would be an easier swap, more power, and everything would pretty much bolt right in. Good luck with whatever you decide to do!
Old 12-14-11, 07:50 PM
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Originally Posted by Tri me
It would be an easier swap, more power, and everything would pretty much bolt right in. Good luck with whatever you decide to do!
Bolded the incorrect part. The Renesis makes 247 whp and 212 whp and it gets a good bit better mpg. If I were to stay rotary I would grab a Renesis.

There was a budget version that made like 189.
Old 12-24-11, 12:43 AM
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thats gonna be alot of work tho... good luck
Old 12-25-11, 07:07 AM
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I think that the renisis idea would be great to see! If anyone does this I hope to see pics!
Old 12-25-11, 08:50 PM
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a renesis would be alot of work to swap into an FC but it would be cool to do. you could buy an HKS turbo kit for it and go boosted. it would be easier to go with a turbo2 swap though just like what everyone else is saying. it can make more power easier then the renesis is what he should have said. goodluck man
Old 07-05-12, 12:04 PM
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Can someone please link a more current article on the subject of Renesis drivetrain swaps in the FC?

For a NA daily driver I think it would make an interesting project.
Old 07-05-12, 12:19 PM
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Originally Posted by RXSpeed16
Quoted from the 2nd gen FAQ.

Can I put the RX-8 engine (Renesis) in the 2nd gen?
Well, technically yes. But it is not a simple bolt-in swap. The Renesis uses different mounts, and an entirely different ECU and wiring harness. Anything can be done, but this is much more complicated then swapping any 2nd gen engine into the car. Lots of fabrication, wiring and other things must be done to support this engine. It is generally easier (and probably cheaper) to swap in the 20B three rotor, or the 13B turbo from the Turbo II.
Even though this thread is 6 months old, it still isn't a feasible swap cost/benefit-wise.
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