Hey everybody. I'm looking for advice on buying a RX8. I want one with a bad engine so I can rebuild it. About all I'm seeing around here are 04s and 05s. Should I wait until I find something newer?
TIA

 

If you dont have experience building rotary engines, leave the rebuilding to a rotary specific professional. Depending on your location, we (the forum) can make recommendations to you on who to have do the work. If you are dead set on going this route, budget at least $4,000 or more to a solid replacement engine while also expecting to have to replace other parts like the radiator, coolant overflow tank, clutch, all with quality replacements and thats not factoring in a few hundred dollars in consumables, oil, and coolant. You will have a solid car when you are done, with a total out of pocket around $7,000-$8,000 when you are done depending on labor rates and what you might be able to complete yourself.

 

I'm looking for a project. I rebuilt a RX7 rotary back in the mid 80s.

 

There's nothing wrong with an early build RX-8, especially because you're already planning to go the rebuild route. Check the recall history though, air bags and the lower control arms are the big items.

The biggest model year changes came with the S2, you can find pages on the forums that outline that. The change that always stands out to me is how they modified the "logic" within the PCM and relays that control the radiator fans. The center OMP injectors that they added with the S2 are only a big deal if you're not premixing, premix on an S1 takes care of that issue.

 

Nothing wrong with an 04-05 as long as it's a manual and you don't care about the engine. Don't buy an auto thinking you'll swap it, it's a deep rabbit hole few found their way out of.

 

If you're capable of pulling your own engine/trans, half of the work for a MT swap is already done. I'm not going to outright recommend it. But if you can find a wrecked MT to use as a donor car, it isn't too bad. Especially because with a full donor you can swap over the locks and ignition switch and just use the donor cars keys without any immobiliser issues.

IMO, it becomes a rabbit hole when you have to cobble all of the parts together from a variety of sources. Mazda really built the AT as a "manual transmission car w/ an automatic" - what I mean by that is, the automatic transmission system is treated mostly like an add-on to the base car.

 

I have read one thread on the AT to MT conversion. Like you said, if you had a complete parts car it seems doable.
Probably more than I want on my first try.

 

Good advice from folks here. Also the starters in 04-05 were crap. Be sure to get an updated starter, it makes a huge difference. Series one fuel pumps also were crap after years of use. . Swap in a Series two fuel pump if you can. And be sure all Mazda recalls were performed. Recalls dont expire and if you can find a dealer whose mechanics still know how to work on RX8, Mazda dealers are still required to do all Mazda recalls for free. Your car would need to be running.

STUFF TO REPLACE, CLEAN, CHECK:

RX8 Club’s recommended maintenance schedule, more comprehensive and proactive than Mazda’s schedule.

30,000 miles:- Replace Ignition coils
- Replace Plug wires
- Replace Spark plugs
- Clean MAF (mass air flow sensor)
- Clean ESS (e-shaft sensor)
- Reset ESS profile
- Clean power steering connections
- Clean battery terminals and clamps
- Replace transmission fluid
- Replace coolant (Mazda FL-22 is highly recommended)
- Replace air filter
- Replace brake fluid (fluid in the brake lines AND the clutch line)
~$300 USD in parts if you shop smartly.


every 60,000:
...all 30,000, plus...
- Clean all chassis electrical grounding points
- Replace accessory belts
- Clean OMP lines
- Replace rear differential fluid
- Replace thermostat
- Clean / Straighten AC condenser fins
- Clean / Straighten oil cooler fins
- Inspect catalytic converter
- Clean / Inspect intake valving
- Consider / inspect all points in 90,000+ as well, many items fail early
~$130 USD in parts if you shop smartly.

90,000:
...all 30,000, plus any 60,000 not yet done, plus...
- Replace coolant bottle
- Replace radiator hoses
- Replace radiator
- Replace front O2 sensor
- Replace motor mounts
- Inspect clutch pedal assembly for flex / weld breaks
~$900 USD in parts if you shop smartly.

At 100k, anything original in the cooling system is really suspect and failure prone. It represents the biggest threat to your engine. Also no original 04-05 Cat would be safe to keep, and that could quickly kill your rebuilt engine.
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Great info. Thanks.

 

You are most welcome, Cheers

 

Another question. Will a MT engine from a Series II car work in a MT Series I car? In other words could I put a 2010 engine in a 2007 car?
Would you need all of the electronics from the Series II car?
Same with the 6 spd MT. Will the late models work in the earlier cars?

 

Not easily if at all. The oil injection setup is completely different and electronically controlled, so if the ECU isn't matched with the engine, it will freak out and you'll never get out of limp mode. The actual oil routing is different too. And if you do swap the ECU it will still freak oit because the rest of the car is different... And there's nothing to be gained by doing this, just get the same series engine.

 

That's what I needed to know. Thanks

 

Series 2 cars brought a LOT of changes, almost all for reliability, a few for performance, and the rest were to make it look more "mature". Better car IMHO (I own one). One major downside is parts availability. There were more Series 1 cars sold (in the US) in one month of the 04 model year than all Series 2s combined. Add to that, the Series 1 guys like to use Series 2 parts as upgrades (as mentioned above), and the Miata guys like our stuff too... A lot of the things are so different, they won't play (engine, rear suspension, electrical, etc.). It took me 9 months to find my car, and I had to ship it from 1500 miles away or something once I did find it. Since then, I've been more or less constantly on the lookout for parts (anyone selling a complete set of clean S2 GT seats, btw?). If you want a cheap and not too difficult project where you don't need a donor car and aren't spending all your time hunting parts, a Series 1 is probably the way to go.

 

That looks like good advice.
I think for this project. I'll look for a 2006-2008 MT car with a bad motor.
Thanks

 

Unfortunately, everything I'm seeing locally is 2004 and 2005. And most of those are automatics.
Who puts an automatic in a rotary sports car?