the european team running supercharged RX8's has reflashed their own ecu's and have posted about it on here. I believe they even have the software to do it on thier website.

All I'm saying is that I do not think Mazda will lock us out from the ECU. Generally, on systems like these, there is always a way to re-flash them even if the memory is corrupted. Otherwise you'd have to toss it. Now maybe they would require a eprom swap in the case of a corrupted unit, but it probably makes more sense to have some hard-load and a fixed-key to decrypt the code. But I really don't know.

I agree the RB tuning will not sacrifice cat life. However, if cat life is the only real issue in the ECU tune, the aftermarket will (hopefully) produce products to reduce cat temps (ie locate the cat farther aft, change exhaust diameter, maybe even a cut-out). I would not be surprised if Mazda is also looking into this issue. I'd expect a new type of cat and/or exhaust on the next round of production (07).

What I really want to know is WHY does the ECU stay in closed-loop up until 6k? I don't see any advantages unless the o2 sensor reacts quick enough to provide timely feedback at these RPMs. If that's the case, then why not make a slightly better sensor and do closed-loop all the time?

Hello Gentleman
The CEL light came on due to the free flow exhaust.When we did the software we had forgot to reboot the ECU...oops...we are installing the silencer tommorow and retuning and rebooting the entire system.
What we have done in the project was the following.
We sent the cars reg numbers to Germany to check what version software we have on the ECU. Since my 8 is a 2005 model they software was fairly updated...I am refering to Flashes here..if your car is before 2003 then it will not work beacuse the software is not up to spec...U have to get it to that level before we can apply the follwoing....
We merely 'Tuned a free flow exhaust system" to the car...we have tuned the car to burn 5% rich as to the preset 15% set by the factory...They do this to preserve the CAT life...think about it with the Warranty they offer it will cost them alot of money to replace the CATs....We have done this in the ROM of the ECU so that when the ECU starts to trim the car out when driving on a long distmace trip , it would calculate from the 5%, and we have tuned the car to a 12.1 on the AFRs , in South Africa we normaly run the cars at 12.8AFR...We have not rewrote the MAPS at all...we just tuned the car...and added a free flow exhaust system...if you remove the CAT and tune the car then this is possible....You have to take into consideration that our Climate pressure on the coasr is 1 bar here at South Africa.If i were to travel inland then the WHP would drop dramaticaly...
We have an M3 that does the quarter mile in 12.1 seconds.With only a free flow exhaust and tuning...Its been done three day ago...we have closed circuit racing here held by the city to prevent street racing...
We hope this helps....
Cheers....

I'm sorry, but can you please elaborate on this statement. This does not make sense in my mind at all. How would you tune the A/F ratios without partially modifying the duty cycle at various rpms? Thanks.

Andy

Could you please be more specific. This info is too interesting not to be developped further.

F

Inquiring minds want to know MORE! Keep us updated. I would like to second the request for more info on the 8 tuners in Europe making their own maps.

look here...

https://www.rx8club.com/showthread.p...ighlight=Astra

We did not rewrite a new mapping system...we just went into the ROM and altered the AFR figures from MAzda's original settings to what we thought were optimum levels for our climate.Mazda runs the engines very rich...u just need to trim the engine out...

That's what I call re-calibrating or re-mapping the PCM!!!

What else can you guy do into the original calibration?

Thanks,

F

I think that when we think about these claims that are being made from one mod or another, we instantly think that they are bogus because they seems so high. We have to take into account that our 8's are not at the original starting point in regards to tuning. If we actually had 247hp from the start, then we could say that...but like "tuj" said, we are try to play catchup just to get back to the hp we should have had.

Consider this, if there had not been an issue of EPA2/Cat Life, the the 8 would have been released with a MAO claimed 247hp. At that point, are we saying that there would be no way to get more power out of the engine without turbo or S/C? Of course not. I do not think that gains of 20-45 hp are out of the question....N/A. Add 10 to what you have now, then think about the gains thereafter. I gained 12 HP in my 1990 Miata by adjusting the timing, and raising the rev limit by 300rpm...I think that there is a great deal of power to be had from this engine, and I think its great that so many companies and people are interested in finding it...you all included. I am sure that Mazda, and Ford are feeling the burn from this EPA2/Cat issue....and it has hurt sales as well. They want to fix it.

Anyone actually think that is they can't fix our stock 8's that they can produce a turbo or S/C that will generate substanially more HP without affecting CAT life? Mazda had a system that they thought they were ready to sell as it was....they didn't plan on making this change. Now trying to address the problem from an economical point of view, they can only re-flash to get the best performance they can. And I do agree that they may make a mechanical production change to handle the CAT life issue, and come back to the original flash(something close) that they started with...

I suspect it would take Mazda claiming 247HP, revised number, just to get the 238 we are supposed to have now. Mazda seems to like to rate 10-15hp higher than actual. ;)

Verified on a dyno? I've been around miatas for 5 years - I had a 1.6L too. Stock? 90hp. I/H/E + timing bump - 110rwhp. Or was yours boosted? If it was, I could see a 10hp gain. If not...it's hard to believe.

I may have erred. I may have had a K&N drop in filter as well...but remember that that 1.6 engine makes it's peak hp at redline. If you were to habitually shift at 5500, you would be missing out on almost 10% of the engines hp. By raising the rev limit by 300, I see these gains at peak...around 7350rpm. I will try and dig up the dyno sheet.

what did you use to raise the fuel cut? I shifted my car at redline all the time....Note attached dyno of my old car, with GReddy Cat back, hot-air intake, and timing bump. It's quite obvious the power drops off well before redline.

https://www.rx8club.com/attachment.p...id=49637&stc=1

These guys at http://www.hfalex.it/ developed a Mazda RX8 Supercharged with a derived R18 Abarth unit: 365hp@8700rpm SAE

WHat a beast!

Kevinb - I can't find anything on their site about it? more info??? :)

I could only find the small link on the home page in the bottom right corner. If you scroll through where that takes you, there is a photo of the 8 in there. Did you read the thread posted earlier about these guys?

https://www.rx8club.com/showthread.p...ighlight=Astra

So, you have not posted for awhile - did you get your questions answered? I'm still curious as to how all of this was accomplished. Let us know - :D

You all are aware that the JDM tuners have been reflashing their ECU's since the beginning... Rmagic, Knight Sports, RE Amemiya, FEED...

So the question is how do WE get into this unit?

I am also curious about RB's approach and test bench. Looking at this as a computer and not a car... why the hell is a test bench needed? That is a "black box" situation by they way they describe it. You shouldn't need to test it to find out how it "reacts"... it's a freaking computer running a program... if they got their software/hardware to reflash from Mazda, then it shouldn't have been a big deal to find out what the algorithm that runs it is either. Especially if you consider that it looks like they've been testing FI solutions for Mazda...

As far as cryptoography goes...I doubt Mazda's swapping keys just like that. What happens when you have to take your never reflashed 2004 RX-8 to the shop in 2008? Their WDS is set running the latest flash and key pair, but your car isn't. Sure you can have it save copies of all the old key pairs two, but how will it know which to use? Does the system lock you out if you fail too many times? What happens in the case of a "bad flash" (i.e. a buggy flash)? DO they replace the ECU? Sounds expensive. What about all the security stuff like car alarm and immobilizer that is built into the ECU and keys (care keys not encryption)? I wouldn't say that rotatin or changing keys is impossible... it just seems improbable.


Maybe our problem here is all in approach.

Having been to RB and seen Jim's ECU development bench and watch and listen while he explains what it does, I can tell you he has the right approach. The ECU in the RX8 is a full-blown computer that does a LOT. Watching the stream of data on his screen it's almost like seeing an artificial intelligence unit in action. The ECU is making changes to the engine's performance on the fly and it varies for each gear, varies for acceleration and deceleration, and for all kinds of factors.

I'm going to wait for RB's mod...it will be worth it.

Heh, the real question is: if the JDM tuners have a solution, why aren't they selling it to the US market?

Because they hate us, of course :)

Nah. That's a great question though!

Really, this makes no sense to me. I want my 8 tuned leaner so that it does not pollute as much as it does now, I have replaced the crappy OEM cat with a bullet proof cat. Why can I not tune this car perfect and help the enviorment?

Language barrier most probably. Translators were always needed in Mazda-Ford meetings I attended in the past.

F

That's right... it IS a computer. The computer on my desk is very complex... it isn't an embedded device like a car ECU, purpose built for real-time performance. The computers (servers, network appliances, security software, etc.) and their underlying technology that I deal with in my line of work is even moreso complex. My point is if the RX-8 ECU is a computer, why not treat it like one?

I have no doubt that Jim will get the job done and do it well. So let's not get on that topic, ok?

That being said... Mazda didn't use a test bench to build and program that ECU. Using a test bench is what you do to reverse-engineer something... when you don't have the source code or schematics. It's done all the time, even in the software industry, but anyone can tell you that nothing is better than having access to the source code.

Maybe working with the code would take longer than a test bench... although one would expect to also have design specifications documents explaining the code and overal functionality. Maybe Mazda wouldn't give it them.... which seems odd if they're gotten the equipment, etc. to re-flash the ECU. We'll probably never know the answer. All I was saying is that... from a purely computer perspective... it's not really the best way to go about things.