Sigh, looks like I have to do the air pump test before getting anywhere on the actual issue of the stage 1 map.... I needed to move the car anyway to change my spark plugs...

thewird

 

 

I honestly wouldn't worry so much about the cobb stage 1 map...it's not that great anyway.

Do your own tune, sounds like you have quite a bit of rotary experience.

 

Sorry, I can't stand misinformation. If I'm wrong I'd like to get that sorted as well.
I plan too but I'm worried about the stage 1 map. I'm sure a lot of owners out there run on the stage 1. And if there is nothing wrong with the map, then I can only conclude there is something wrong with my car. Either way I'd like to find out.

thewird

 

Read this again .................

 

Airpump is only on for a very short period of time after startup.....it's electric..not like the old RX-7's that had a belt driven pump that was on all the time

The Renesis idles at close to stoich due to the altered ignition timing that the stock ECU uses at idle..it fire the trailing plug first.....

 

Thewird, I saw similar things when I tried the stage 1, so I stopped using it. I saw others on the forum mentioning the same thing, so I don't think it is anything wrong with your car.

Sidenote - 146 kph... With certain laws in effect in Ontario, an awful lot of my logs peak at just about the same place!

 

I stand corrected on the air pump. It does not function once warmed up as mentioned. Interesting the idle timing is -5 leading, 10 trailing. I did not realize the RX-8 ran negative split at idle. But there must be something more to it then just the split to be able to run 15 AFR's. Learning as I go along I guess.

I don't see that is how Cobb intended it to run though. That lean of an AFR would surely do engine damage with prolonged use. I don't see how Cobb could release something like that as a "Stage 1". Even if its not the greatest map in the world for power/smoothness, I would expect it to be at least marginally better then stock with a slightly leaner AFR, not an overly unsafe lean AFR.

As for the speed, meh. I've done worse, pegged my speedo in the RX-7 before testing the shorter JDM 5th gear (290+ km/h).

thewird

 

huh?

are you talking about before or after open loop? i wouldn't expect afrs that high with cobb 1 after open loop.

 

Obviously open loop during a WOT pull. Maybe its model year specific since there are different maps for different years. Mine is a 2005.

Well, it was a semi-warm day yesterday so I changed my spark plugs. But look what I found on the rear trailing side... I thought this might be a possible reason for the leanness since if its not burning the fuel, it will register lean. But loading the stage 1 map again and driving for about an hour, trying to do a pull again and it did the exact same thing, 14-16 AFR. I left the stage 1 map on there just to see if it changes over a longer period of time but I doubt it.



thewird

 

Seriously, anybody who thinks that their engine not burning fuel causes a lean condition has no business doing their own tuning. Based on everything posted here you have no idea what you're doing. I held off saying it earlier, but that last one is a real doozy

 

An o2 sensor reads oxygen, if that oxygen isn't being used in the combustion, the o2 sensor will read more oxygen, therefore learner. Think before you post such a statement.

thewird

 

Do you mean think like how the air pump really works before you argue with people?

Or do you mean think like the leading plug should still be firing and putting out incomplete combustion in open loop (AFR = Air/Fuel Ratio)

Or perhaps you mean think like what was the AFR reading before the change and is the engine in proper operating condition; no defects in the ignition, fuel, and air systems?




.

 

Why are you posting? I don't get how either of your posts are helpful in any way? I can't even make out what your trying to say in your last 2 sentences.

thewird

 

I would suggest you take an autoshop class.

 

The Rx-8's can idle leaner than a peripheral exhaust port engine because of the lack of overlap and also a different firing order used on the Rx-8 PCM. The leading is NOT waste sparked on a Renesis, and negative split is utilized. The ignition system is actually much better on the Rx-8's despite the very weak coil design.

Can you email me the Rx-8 stock and stage one maps? I have Accessmanager and Accesstuner race for Subaru, I think I might be able to pull them up.

 

When you have a missfire, or improper ignition...your AFR is anyones guess.....depending on the location of the sensor it can read rich, lean..or all over the map...

You need to fix the underlying problems before you can tune....simple as that...I think that was what Team was trying to say in his ever gentle way

You need to try and look at the RX-8 as a much different system than the RX-7's. The PCM is much smarter..and much more intrusive

 

The Rx-8 PCM is just like the Evo's and the STi's. They're all Denso based and they all use a similar processor. Of course there is different hardware attached but's the same basic thing.

 

It's all in his first post

yes I'm a jerk, but since you came here asking for help and then proceded to argue with people more informed than yourself I felt like we could talk jerk to jerk


.

 

Misfires can 100% cause high oxygen readings, but you can't be sure what's going on without the proper equipment. There are 5 main gases produced by a car and they all need to be read to be sure. The five gases are HC, CO, NOx, CO2, and O2. A misfire can cause high O2 readings and high HC readings because there is insufficient combustion... you have more free oxygen but also other pollutants in the exhaust stream. The best way to ascertain what's really going on is to hook the car to a 5 gas analyzer that a shop would have.

This is from a Toyota emissions diagnosis training course:





Please, don't make an emissions diagnosis without the proper training or equipment.

 

There's definity a problem, but the proper analysis is needed before blaming the Cobb tune as was done. That means putting the OE tune back in and starting with the basics.

Otherwise, go pull the wire off a trailing plug and let us know what the before/after AFR is ....

 

I intend to examine the Cobb maps myself if I can get what I need to view an Rx-8 map on a Subaru installation of access tuner.

 

What's in my first post?

I already admitted to being mistaken about the air pump after testing it myself. I pulled the fuse, it read the same, I didn't believe it so I disconnected the air pump manually, and it read the same. I was never arguing with anyone? I had assumed it worked similar to the 3rd gen where its on until 3,000 RPM and when I tune them, I pull the connector until I get the drivability tuned.

Aside from arghx7's explanation, in my own experience tuning a 3rd gen I once tuned a car who had bad coils and would randomly go leaner at higher boost when I knew the fuel map was perfectly fine. After checking fuel pressure which was fine, noticed how the dyno graph wasn't as smooth as other cars are. We changed the coils and voila, car went richer.

Thank you for that explanation about how the RX-8 can run leaner at idle. I do know how the RX-8 ignition control system is improved.

I don't think you'll be able to open them but I'll send them to you when I get home nevertheless.

Now getting back on track, at this point in time I don't believe there is something wrong with the car but It's not ruled out of course. The car works perfectly fine with the stock map as you can see from the datalog.

Also, the rear trailing plug was firing since it was not fouled. I only loaded the stage 1 map on because there was always a possibility that at higher RPM or higher speeds, the vibration could loosen it and make it lose contact (the metal piece was still in there, just broken). So I took it for a drive to see if anything changed and it didn't.

I never blamed Cobb. As you see from the thread title it was possed as a question and not an accusation. What I find odd is that the stock map works fine but the Stage 1 does not. From my understanding, there not supposed to be much different.

thewird

 

Read this SAE paper on the Renesis: http://www.rotarydevelopment.net/Rot...790_Rotary.pdf

it explains that the air pump is not used AT ALL during normal driving on a Renesis. That is because using side exhaust ports gave Mazda the flexibility to eliminate the overlap between intake and exhaust as I'm sure you're aware. Without the overlap there was a 30% reduction in the internal EGR effect which that diluting the intake charge on the REW. That internal EGR effect was the reason why the REW required such a rich mixture and then an airpump on top of that to keep emissions down. There's also a redesigned injector air bleed/atomization port design... it's a lot of cool stuff in there, especially to people who are so familiar with the old designs.

The Renesis is so much better than the REW in so many areas. The only thing the REW has over the Renesis is the simple fact that it was designed to be turbo from the start. And that makes a huge difference in the end to the normal enthusiast.

Also, please email me what I requested in the PM.

 

i can post a screen shot of it for you next time i have my ap in the house. i doubt you can see it with your subaru racetuner. maybe you can i guess.

it's barely different from stock. seriously, there is no reason it should cause such lean conditions in a car that is functioning properly.