Bought a 2004 rx8 that won't start. thinking about putting a ls2 in it.
10-31-2014, 02:11 PM
#4
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No flaming allowed in the new member forum.
That being said, you won't find people that are just going to give you a thumbs up.
Basically, the RX-8 is a terrible platform from an ease-of-swap perspective. Not only is the factory engine in a spot that other engines can't be in (which means you are custom rebuilding most of the front of the car's subframe, suspension, steering, etc...), but EVERY electronic component in the RX-8 is run through the factory ECU. In order to have a seemless swap that isn't like driving a pile of electronic spaghetti or a christmas tree of warning lights, you will need to design/develop/write custom electronics modules to communicate with everything OR find aftermarket replacements for everything. This is where most builds end up bogging down and either stalling completely or their owner claiming it's "done" as long as you don't get within 50 feet of the car.
This is all on top of custom everything else: exhaust, cooling, oil cooling, ppf, mounts, wiring harness, driveshaft, etc...
There has been ONE LS swap that actually reached the full "completed" stage, done by TougeFactory as a "cost no object" swap, and it was up for sale a month later for $69k, and it still hasn't been sold to my knowledge, several years later.
So if you have LOTS of cash laying around, you have a fair shot at getting it done if you spend all of that plus however much you can scrape together. Every single person that shows up on the forum posting about it and thinking it's a simple/cheap/easy swap has proven how misguided they were (Even if they still don't realize it).
The easiest engine swap available, if you want more power, is to swap to an REW. That is ~$12k, and can be ingrated with the electronics fairly easily.
Alternatively, the easiest, and cheapest, swap possible is to swap the chassis, and just trade the car for something closer to what you want. Seriously.
Feel free to try to prove us wrong. We keep waiting for someone to do so...11 years after release, and no one has yet.
That being said, you won't find people that are just going to give you a thumbs up.
Basically, the RX-8 is a terrible platform from an ease-of-swap perspective. Not only is the factory engine in a spot that other engines can't be in (which means you are custom rebuilding most of the front of the car's subframe, suspension, steering, etc...), but EVERY electronic component in the RX-8 is run through the factory ECU. In order to have a seemless swap that isn't like driving a pile of electronic spaghetti or a christmas tree of warning lights, you will need to design/develop/write custom electronics modules to communicate with everything OR find aftermarket replacements for everything. This is where most builds end up bogging down and either stalling completely or their owner claiming it's "done" as long as you don't get within 50 feet of the car.
This is all on top of custom everything else: exhaust, cooling, oil cooling, ppf, mounts, wiring harness, driveshaft, etc...
There has been ONE LS swap that actually reached the full "completed" stage, done by TougeFactory as a "cost no object" swap, and it was up for sale a month later for $69k, and it still hasn't been sold to my knowledge, several years later.
So if you have LOTS of cash laying around, you have a fair shot at getting it done if you spend all of that plus however much you can scrape together. Every single person that shows up on the forum posting about it and thinking it's a simple/cheap/easy swap has proven how misguided they were (Even if they still don't realize it).
The easiest engine swap available, if you want more power, is to swap to an REW. That is ~$12k, and can be ingrated with the electronics fairly easily.
Alternatively, the easiest, and cheapest, swap possible is to swap the chassis, and just trade the car for something closer to what you want. Seriously.
Feel free to try to prove us wrong. We keep waiting for someone to do so...11 years after release, and no one has yet.
11-01-2014, 02:19 PM
#7
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Well, at least the seats are the right color to hide the result when the bills start becoming overwhelming. 
J K. Hope you have the patience, knowledge, perseverance, time, facilities, equipment and capital to pull it off and a sufficient sense of humor if it doesn't work out as planned.
J K. Hope you have the patience, knowledge, perseverance, time, facilities, equipment and capital to pull it off and a sufficient sense of humor if it doesn't work out as planned.
11-01-2014, 03:15 PM
#9
I have to do one last push to convince you to not attempt it.
Have a look at the Frankenstein RX-8s Subforum
You'll notice quite a few build threads that just go silent at some point through the build. Most that attempt a swap with a non-rotary never get anywhere near a completely functional product. If you intend to only run this car as a full race car, going with zero factory equipment it becomes a much more reasonable project. If you do that then it's no different than any custom race car build.
If you intend for this car to be streetable, let alone completely legal there are massive hurdles to jump over that RWWIP went into a little bit. Quite a few of them have to do with the fact that most of the factory diagnostic components would need to be functional to be legal in most of the US.
I'd really like to know what your goals and expectations for the car are. Allot of the people that attempted it started out looking for completely unreasonable things (400hp LS1+Rx8 handling, daily driveable+400hp, Rx8 handling+torque, etc...)
Good luck, be sure to let us know how it goes.
Have a look at the Frankenstein RX-8s Subforum
You'll notice quite a few build threads that just go silent at some point through the build. Most that attempt a swap with a non-rotary never get anywhere near a completely functional product. If you intend to only run this car as a full race car, going with zero factory equipment it becomes a much more reasonable project. If you do that then it's no different than any custom race car build.
If you intend for this car to be streetable, let alone completely legal there are massive hurdles to jump over that RWWIP went into a little bit. Quite a few of them have to do with the fact that most of the factory diagnostic components would need to be functional to be legal in most of the US.
I'd really like to know what your goals and expectations for the car are. Allot of the people that attempted it started out looking for completely unreasonable things (400hp LS1+Rx8 handling, daily driveable+400hp, Rx8 handling+torque, etc...)
Good luck, be sure to let us know how it goes.
11-01-2014, 03:35 PM
#12
There seems to be a surge of new LS Swap RX8 projects. It seems like the best place for information so far is the LS Powered RX8 group on facebook.
I'm working on swapping an LS3 with the V8 Roadsters kit.
Are you using a kit or are you making all of your own components?
Interested to see your progress, best of luck.
I'm working on swapping an LS3 with the V8 Roadsters kit.
Are you using a kit or are you making all of your own components?
Interested to see your progress, best of luck.
11-01-2014, 04:21 PM
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If you have the money and skill to build that, then you might have a fair shot at this. Not the typical 16yo kid that doesn't even know what a proper 250whp is and only has access to an iPhone.
Good luck. If you want to start a build thread, feel free to start it in New Member subforum and I'll move it over to the right subforum for you.
Good luck. If you want to start a build thread, feel free to start it in New Member subforum and I'll move it over to the right subforum for you.
11-01-2014, 04:32 PM
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No one believes anything posted on the internet. Or everyone believes everything. 
Trying to convince people of what you might be able to do is largely pointless, it's best to just go do it.
Trying to convince people of what you might be able to do is largely pointless, it's best to just go do it.
11-01-2014, 11:21 PM
#23
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It just occurred to me: why a LS2? Why not wait a bit and install the modified hemi from the new Hellcat? At roughly 700 horsepower, it would get you closer to your 900 HP goal in the first stage.
11-02-2014, 12:11 AM
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11-02-2014, 01:26 AM
#25
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Let me get this straight....the motor from a discontinued product line of a company teetering on the verge of bankruptcy has more going for it than one of the best selling and most coveted engines on the market today. Is that what you are saying?
Last edited by Mysterion; 11-02-2014 at 01:30 AM.