You want to have 99 horsepower in a 3000lb car? If you're going to spend the significant amount of work and money to swap an engine, there are much better and reliable engines. 1JZ's are plenty reliable..

 

I think its a fantastic idea!

 

Of course it's not a matter of power cause i could do a 2jz swap, but it's a matter of fuel economy, for a daily vehicle. So why is it so dumb?

 

There's a few things to consider: do you want air conditioning? Do you want the speedometer to work? What about the other gauges? Do you want the electric power steering to work? Do you want the ignition key to start the car, or make up some kind of solution?

Any swap into this car is pretty complicated, so suppose the whole venture costs you $10k in parts, custom work and troubleshooting, which is on the cheap side, you'll break even in about 110,000km (at my local gas price.. if you're in the US, it's probably closer to 200,000km. Do you plan to drive that much?

 

The RX8 is a rather complicated platform to work on for a "I could do this to be more fuel efficient"

The reality is, while it may be more fuel efficient, it will drop 70% of its functions, and be the only way to make an RX8 less reliable than it was to start with.

Too many RX8 swaps are hack jobs, with tons of **** over looked, and in the end the car is half as refined as it was to start with, which is sad for it having a wildly mediocre powertrain from the get go.


(Not to say my swap is anything close to perfect, but I have avoided "good enough" things, like reusing the POS factory fuel system)

 

So any other suggestions based on my standards (nearly 100hp 1.3-1.6cc)? Or i have to change platform?

 

You could by a Yaris and have a body shop do a custom fit rx8 body kit... It would be more reliable.

 

Anything is possible with enough money, but since your goal is economy, any swap into an RX8 is going to be a challenge. The choice of engine makes very little difference, the complication is in the interconnected and computerised systems that are all over the car.
More people have done V8 swaps than Yaris swaps, so there is some information available to help you, but with an econonbox engine, you're kinda on your own.

But again, it depends on what compromises you can accept.. A/C, steering, firewall cutting, various wiring hacks...

 

Anyway i'm gonna ask my engineer some questions but maybe i'm gonna buy a diesel yaris since economy is my goal nowadays. Thanks for the tips

 

haven't seen any ford/mustang engine v8 swaps ?

wondering why ?

motors are easy to come by ?

 

I have a 2005 and i want to take the rotary out of it and put something faster in but i dont want to have to do alot of modifications, What would be the best engine to turn it into a monster?

 

You’ll shoot your eye out kid.

an engine swap is a lot of mods, especially with a monster engine that also needs a new heavy duty drivetrain.

 

Like Team already said, these things are conflicting.

Even REW swaps need a lot of effort, any piston swaps are even more effort.

Cutting corners now will cost you more down the road.

My advice: sell it, buy an old Mustang/Camaro/Corvette and start there.

Also some of the older posts are hilarious. If you want Yaris economy, buy a Yaris, derp. Doing an engine swap to save money on gas is like ripping money apart and gluing it back together. Makes zero sense financially.