jaz24

Hi,
I’m new to the forum, and I do not own a RX8 I joined this forum to decide if I should go for one.
I’m looking for a new project and have been thinking about swaps for awhile i owned a NC Miata and was considering doing it, but after 8 years of ownership I was offered almost what I paid for it new, and it was just too nice of a car to cut up so I sold it.

I’m in my 50’s and have been a mechanic my entire adult life, I have not done a swap since the 90’S, but I’m feeling the itch again, but technology has changed a bit….lol.
after some looking the RX8 looks to be a great candidate, because they are easy to find in good shape with shot motors, I’m not looking to build a track machine just a reliable driver, I think that an LS may be a bit much for it (am I wrong?) so I was thinking about a LFX.

I have not had alot of experience with the ECM stuff but I’ve done a fair share of making stuff work with factory electronics, so I’m confident I can figure it out (with help), and the challenge of it and learning are the main reasons to do it in my opinion.

The fab work doesn’t worry me just the electronics, if I do it I’d like everything to work as it should right down to the warning lights and such.

the questions I have are;

1 what is needed to keep everything in the car working normally gauges etc.(do I/ can I keep the factory ECM to run a bigger engine or to run the rest of the car) can the car work without the factory ECM and a standalone engine ECM?

2 is it possible to keep the transmission and rear end and use a different engine, if so what engine? (I suspect even the LFX may be too much for them)

3. how much HP can the OEM stuff handle?

4 am I crazy for not considering a professionally built Renesis engine or building one myself (never touched a rotary, I understand the theory but I’ve never worked on one, confident I could do it though), I've read they are not reliable and require special care, not very efficient on fuel etc.

any help is appreciated, Thanks.

Left4Dead

Well welcome to the forum. There is a sub section here for engine swaps both rotary and non rotary.
The LFX is a very popular swap and made even more so by Keisler Automation look them up if you have not already they make a plug and play kit that would surely give you all the answers you need for electronics.

Now the question of can a rotary be reliable. Yes it can. They do need some added care. More frequent oil changes and the engine is designed to consume oil to properly luibricate its rotor housings, You being a machanic for years I would think would have no issues with things like that.

Read the new members section must read post
https://www.rx8club.com/new-member-f...t-here-202454/

jaz24

thanks for the quick response, i have been looking trough the other sections and would have posted it there but I’m limited to here for now being a new member, but good info. Thanks for the info about Keisler, gives me more to look at.

is the increased oil consumption and oil change frequency the only thing? If so I may give it a go, I can see how people without knowing the quirks of the engine would lend it to getting a bad rep, and have seen enough to know that’s probably the case, honestly thats what is peeking my interest, its a good looking car and they can be had cheap because of the bad rep and the fact that most of them are probably trashed by people not asking questions and just driving to destruction.
I was reading people talking about adding oil to the gas to keep the motor good but I think that could lead to clogged cat and muffler, o2 sensors etc.
that would make it a much simpler project, but it means less challenge too….
Thanks again.

Left4Dead

So the reason the engine uses oil is to lubricate the rotor housings. There is an oil metering pump that dispenses the oil but under light load it is not functioning anywhere near as much as needed hence the premix as a prevantative measure.

these cars do not like gramma drivers. They need to be revved out regularly to clean the carbon deposits.
Most people will remove the cats in a rotary to prevent clogging because yes that can be an issue otherwise.

last year I bought an rx8 with a blown motor with the jntention of doing an LFX swap but ended up reading learning and loving the sound of the rotary.
I also have a friend who did the swap and gained himself between 2 and 3 seconds at our local race track so for me that was a huge investment for in my eyes minimal return.

My vote would be to keep the rotary and at least give it a shot , if you dont like it the motor can be easily sold later on

jaz24

Thanks for the info, I was always curious about the rotary motors but never looked into them, looks like now may be the time to learn, I spent hours yesterday reading trough this forum and now I’m more curious about the engine than ever……