Theoretically, if horsepower was not a key factor, what would be the easiest non rotary engine to swap into an RX8? Lets say you didn't care all that much about power, speed etc. Your only desire was to turn your RX8 into a mid nineties carolla...what would you do?

 

A Renesis.

 

Nothing is going to be "easy" any engine will require custom mounting points, transmission mounting points, Power plant frame modifications or delete. Boat loads of wiring and the like.
Also being an OBDII car with a canbus system you'll have your work cut out with emissions and getting all the OEM equipment to work like the electronic steering, gauge cluster, abs etc...

 

LS was a pretty simple swap for me. That word is relative though. Some people in here will tell you that if it doesn't exactly function like stock then it's a piece of crap swap. Well if that's the case swap in a motor that commits suicide at an early age. Maybe a motor from Seattle or Alaska. But on a serious note there isn't a best option. Just the one you are most familiar with physically works.

 

not to thread jack, but I really want to do this swap myself. Mind telling us what you got into the swap? $$

 

I would think any engine that fits would be about equal, in cost, time, and trouble. Granted some engines are cheaper and have parts more available. A gm 4.3 might be a little easier to fit. I'm not sure but i would guess its a bit shorter than the ls. And that might save some fab work.

 

Not gonna reveal that number bc I may sell it soon. The 4.3 is lb for lb the worst engine produced. Only reason it beats the rotary is bc that V6 is HEAVY. Plus it's 2 bolt main and not a very good platform to make a lot of hp. They are notoriously long lived though

 

The 4cyl engine out of a NC Miata would be the closest of anything to fit a RX8.

 

But then you are left with the same amount of power. Much more reliable though

 

Basically the same suspension/chassis setup, wouldnt surprised if basic engine mounts and it would otherwise bolt in. Of course there is much more in regards to wiring, and other supporting parts.

 

That would basically just get you a piston engine lol, I wouldnt bother but I would say that would be the simplest non rotary engine swap for OP

 

LOL, yeah a Miata ND Chassis and the RX-8 are very similar. Jesus Christ, why don't you guys go to the norotors site.

 

Getting back on track, likely the NC MX5 engine since the NC subframe bolts right it. Mating it with an S2 RX8 trans puts the PPF mount on the correct side. I suspect the PPF and driveshaft length may need to be modified, but how much if any would have to be determined after fitting the new engine/trans combo.


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Take it to the "fun" thread....and tone down the personal crap or there will be some moderator induced cooling off periods

LSXREX...you have been banned already for similar behavior...the next one will be longer

 

thanks for the interesting replies bros. Curious because I'm looking for snow tires and to fix a few things on my 8 and everytime I do I just have the horrible feeling of "this car's engine can literally explode/fail at any minute and every dollar you put into it can be lost TOMORROW. So for that reason I've always felt a terrible guilt about putting any kind of money into this car. While no car is an "investment" (all cars depreciate), no car has seemed like more of a liability then this one, which is such a shame, because its a great car that happens to have a time bomb ticking inside it.

Miata is an interesting response because it is so easy to turbo a miata. Theoretically couldn't you turbo it and get more or close to same HP as the rotary?

Also, what about the engine in a mini coop? Its small, high compresion,think its mounted in a weird way though.

 

miatas are not really easy or cheap to t/c. im sure riwwp will stop by here shortly. he has a msm

 

It's incredibly easy to turbocharge a 1990-2005 Miata. But swapping in that engine is the same level of complexity as an LS.

The NC's engine (2006-2015) uses the same subframe mounting points and transmission as the RX-8, exhaust exists on the correct side, etc... When Mazmart swapped in a Renesis to an NC, they just remove the NC's front and rear subframes and bolted on RX-8 subframes.



The high ride height is because of the RX-8 suspension that expects there to be 3,000lbs sitting on it instead of 2,400lbs, this is before they addressed any of that.

From there, it's a matter of the exhaust and coolant system custom design, plus the wiring and some electronics module integration, but even that is simplier than any other piston swap because it's all Mazda modules. For example the NC's immobilizer can actually be reprogrammed by a dealer to recognize an RX-8 ECU.

The reverse is essentially the same, just with the NC's engine in an RX-8. Of course, you would lose power and torque, not pick up much gas mileage, although the engine is generally more reliable.

Turbocharging the MZR has been met with limited success. Only a few companies make kits, and they all have quality problems (sound familiar?). On the other hand, $5,200 gets you a 100% complete the Mazda-backed supercharger kit that fits and functions like OEM (because it was designed for OEM until Mazda backed out). Puts you up to about 230whp.

So adding that gets you to a bit more than you can get from a Renesis, with easily more torque, and your gas mileage drops down to about what the RX-8 makes anyway.

It's a swap that has no gain unless you boost it, and if you boost it, you will have to essentially make a custom turbo kit in order to actually exceed what the RX-8 gets from a Renesis already.

So yeah, people don't bother.

 

my point was even the oem msm have issues (cooling for the most part) and most of us know your issues with miatas. if you could quit messing with **** you might have a reliable turbo miata lol

 

Yes, virtually all of my problems are self inflicted

The "ease of turbocharging" is really high simply because there are established reputable companies that sell literally complete kits (down to tubes of locktite and other consumables needed) that you can bolt on and it will last forever if you don't touch anything. There was recently a customer 'report' to FlyinMiata from one of their early customers. They added an FM turbo kit to their 1990 (1.6L) at 60,000 miles on the car. The car just crossed 250,000 without a single drivetrain or turbo failure. Only basic maintenance.

All of the problems end up coming from pushing up the limits and demands, tracking it, and messing with stuff But that's true of any car/mod

 

that SC kit would make a nice street ride ... would probably need the FD3 RX7 3.90 R&P though

 

As many mentioned, nothing is easy, it just boils down to what your specs are and what is the purpose for your car.

 

I tend to agree with most replies here. There is no perfect swap, there is certainly no cheap swap. If this is more about the journey than the destination, knock yourself out. However, beware, you might end up at an expensive and crappy place at the end
If you factor the money required for a proper clean swap, even if you do the work yourself, you will never get it back upon resale. If you are worried about reliability, and indeed you engine blows up, it would always be cheaper to throw in another Renesis and flip the car.
Having said all that, I do not take my own advice very well...
Now that I finished my V8 car, I am already planning a proper 13B REW track build
Speaking of swaps though... A friend of mine who is well respected rotary engine builder and accomplished racer, recently built himself an RX8 commuter using a VW 1.9TDI engine. Just food for thought.

 

Is there any potential for GM LFX engines as an alternative motor choice?

V8 Roadsters already offers a kit for the miata and I reckon they're a bit more accessible than parts in the LS powertrain. IIRC they're decently lightweight as well. While a V8 swap has obvious potential I'm wondering if there's more than "LS swap, bro" as an answer.

Is there any glaring reason that wouldn't work? (ECU communication issues aside.) I've always thought that if the RX8 hadn't had a rotary a 6cyl would be appropriate.

 

I'm thinking to buy an old rx8 and swap an auris 1NR-FE Toyota engine. I'm looking for the Toyota's reliability and rx8's good looking. What's your opinion?

 

I think that is one of the dumbest ideas I have ever heard of.