ECU Tune
(will void the warranty if found)
There is no known ECU tuning method for Series 2 (2009 - 2012) RX-8s. The ECU changed in critical ways and no company has yet been willing to spend the time to hack the ECU to determine how to flash it. These ECU points all relate only to the Series 1 RX-8 (2004 - 2008)

ECU tuning is often recommended, as it can improve a wide range of dynamics about our car, including throttle response, overall power, ECU triggered safety items such as OMP injection rate and fan trigger temp, etc... Power gains are limited to about 10hp maximum, though your gains are largely dependent on how bad the OEM tune is for your particular combination of engine and sensors.

Other debatable items such as increasing the rev limit are possible, though should be thoroughly understood before pursuing.

As for HOW to modify the ECU, there isn't much for options. There are some aftermarket full ECU replacements out there, but they are expensive and quite a bit of work. ECU tuning has some options, with the best option being through the COBB AccessPORT. A few companies put the effort into hacking the Series 1 ECU and were successful, though only COBB actively marketed a product for it full scale. They did not hack the Series 2 ECU however, and Mazda changed it enough that a full hack was needed. Too few cars were sold, too small of a possible customer base, for COBB to see the pay off in doing the work. The AccessPORT was also discontinued for all naturally aspirated cars (not factory T/C or S/C) in 2010(?). Mazdamaniac was able to negociate a deal with them where he would become the sole dealer for the RX-8's AccessPORT, COBB just needed to supply the hardware and he handled everything else. Unfortunately, even this route has come under trouble, as Mazdamaniac was banned from RX8Club.com in March of 2012 due to vendor related complaints. Whether or not he will leave the community entirely and shut down his sales/tuning of the RX-8 is still unknown. The tuning through the AccessPORT does not require his tuning services however, as there are other tuners that are successful at producing viable tunes for our car, and the AccessPORT is just a tool. The only exclusivity he had was his remote tuning service (no one else decided to offer it), and after the discontinue, the dealer sales of the AccessPORT itself. Be very wary of tuners that claim to be able to tune "because they can tune piston engines" or "because they can tune RX-7s". There are differences between older MAP based and MAF based tuning, as well as dramatic differences between piston and rotary engine tunes. Make sure that they know MAF based tuning AND rotary tuning.

The Racing Beat reflash is also a viable option, and follows a similar concept as the AcccessPORT, only you send your ECU to them, no hardware to purchase (but you don't get the benefit of the extra hardware either).

Piggyback ECUs are problematic and unreliable, but possible as alternatives.

Every single "ECU chip" is a complete scam for our car. At best it's the same as taping a couple $100 dollar bills to your ECU, at worst it can fry your $1,800 ECU. Our ECU is too smart to be fooled into doing anything more than a few miles, and the OEM tune is already close enough to perfect that the ham-fisted approach of trying to fool it in a narrow set of circumstances while crippling it in the rest is a recipe for engine destruction.

Engine Tuning subforum: Engine Tuning Forum - RX8Club.com

COBB AccessPORT, or any other kind of flashing device for tuning
(will void the warranty if found)
This is more of a sub-topic of the ECU tune, but it seems that it needs it's own section, as it really isn't clearly spelled out anywhere.

The COBB AccessPORT is a tool, much like a wrench. To us, you are asking: "Can I remove my engine with this wrench?" Well, kinda. It's part of what is involved. You won't be able to make any progress without it, but even if you have that wrench, if all you do is hit yourself in the face with it, you won't get anywhere toward your goal. It has to be used appropriately, and it is simply one of many pieces that you will need to get there.

In more practical terms, the AP is nothing more than a communication device, a phone if you will. It can communicate with the OEM ECU. What it tells the ECU is entirely dependant on what information you are pushing through. If all you are pushing through is requests to clear codes, then that is all it's going to do. In order to increase the rev limit, you need to have the AP "flash" a map to the ECU.

But you have to get this map first.

Well, what is a map? A map is basically a digital copy of the ECU's parameters and tables that it uses to manage the car. Much like if you right click on a picture on the web and click "save-as" and save it to your computer. Just like that. You can upload that picture to the web if you want, and everything is exactly like it was.

But, you want a change. Lets say that the picture was of a girl with a big mole on her face. You wanted to touch that up and remove it. Well, you will use some other software to make those edits. Then you have to upload the new picture to replace the original. That's all the AP is doing when you flash a map. It's uploading the digital copy of the ECU's data files.

What tuners do, is they make edits to the data files to adjust fueling, timing, CEL blocks, rev limit changes, etc... as needed. Then they load them into the AP via USB and use the AP via ODB2 to load the flash to the ECU, applying the changes.

So you can get the AP to help you toward your goal, but you will also either need the software to make the edits AND the knowledge of what you are doing (because it's not a simple process of point and click), or you will also need the services of someone that does have the software and does know what they are doing. If you pick the 2nd option you will also need to pay them a fee of some sort, and probably work within their scheduling.