Can't really tell from the resolution on the graph...the uncorrected software on the CanScan says the car is running 13.6-13.9 at closed loop. WBO2 says it is more like 14.6ish. So using the raw data you are thinking that you are a lot richer than you really are...some people tuning with the non-corrected version were having trouble with pinging when they tuned too lean.

No...I'd like to see an Aussie version though. Send one to me or Nemisis....we want a look:D

 

The problem is you are trying to display AFR. That is a calculated value based on multiplying the Lambda value by the stoich value for the fuel. It is "roughly" 14.7 for "petrol" (gasoline).

Lambda is more specific. 1.0 means stoich no matter what the fuel. Even Nitromethane. It is a measure of the O2 in the exhaust, independant of fuel. That is why I like it so much.

The RX-8, according to my logging in "closed loop" runs very close to 1.000 Lambda - consistently. I am talking about values like 0.99 through 1.01. It does a very good job at it. So what I am saying??? ...

I scratch my head at some things certain vendors have tried to make people believe. Sorry for the -ve comments, but I try hard to bring the truth in my products. It might cost me some sales etc, but I can sleep at night.

 

SO why does your graph show it is limited to the lowest as 0.758? I get that value sometimes and seems it is the limit of the Wide02 range.

And the highest of course is when the throttlepct is lowest and the value is 1.375?

Could you explain to me why?

 

How about... Physical limits of the sensors?

 

oh really??? crap :o

 

The graph supplied by Hymee (with Snap-On as a participant) came from my RX-8 this past Sunday.

With the Racing Beat REVi intake installed, the VFAD has been removed. There are no other modifications that would / could affect the readings provided.

As stated earlier, for the true enthusiast, this tool will be invaluable.

 

I guess the only problem is that the "sensor" in this case reading Lambda..is being used to tune by people assuming that it relates mathematically to an A/F range that they want to tune to. This has to be watched...unless the differences are explained.

I'm very impressed with what I have seen...The interface looks great. And with the extended value PID access...this tool will rock

 

are there any plans for a windows PDA based program in the future?


Oh, and the graph you are seeing the secondary and tertiary ports opening. Also the stock O2 sensor is good for areas right around stoich but need a correction curve when you get away from stoich (no transmitter is completely linear so basically you always linearize the part of the transmitter you will be using - which for stock purposes is stoich for closed loop control).

 

heheh i just talked to that person on the phone a couple of days ago hehehehehehe
:D

 

you'll be able to see it in my car this weekend well the version i have that is

 

I disagree. A linear sensor, although not really linear in response, will give the correct lambda value. The PCM contains the sensor's transfer function, therefore taking account of the exact characteristic curve of the sensor's response.
The sCANalyser use PCM parameters and therefore, the signal coming from the lambda sensor is correct and can be trusted.

Fabrice

 

they are already assuming that when reading an afr- because they have not actually using the correct stoich value for their fuel. so using the afr reading is a "best guess" and not a true data point.

 

wait wait wait- Hymee your graph is saying that at the points where the s-dais operations take place the actcual airflow over the maf DROPS?

 

I'm not Hymee .... but, yes.... the airflow drops.

 

except the transfer function in the PCM is a linear interpretation of a sensor that is not linear, which is why CZ found that the stock lambda was not matching up to another WB02 sensor he installed at ranges other then stoich and he went through the process of contacting the manufacturer and getting their curves and comparing it with his own O2 sensor.

Mazda does not have the entire transfer function of the O2 sensor in the PCM because it is only used for their purposes around stoich for closed loop control.

 

That's a great description. Mazda has no need to tell us what they are doing with the Lamba data from the sensor once it's in the PCM..........That is the whole problem with this car....it's WAY too smart. All the things that used to work reasonably well to get power don't work so well when the car can compensate for them.

I guess what I was trying to say is................

" Be careful tuning using uncorrected Lamba Data "

Otherwise...why would we need expensive WBO2 sensor software...

 

Interesting and strange. But possible, as sCANalyser and SCANcan users have probably noticed the PCM only work in close loop in stocih conditions.
But then, why did they fit the RX8 with a wide band sensor whereas a switching HEGO would have done the job perfectly? Is it for monitoring / diagnostic purposes?

Fabrice

 

Forget all the arguments about linear / closed loop only etc.

I have done my own tests with Phil using TWO other wideband O2 sensors, one with a Motec display unit, and also another with its own display.

All three were tested together, at the sime time. All the readings "matched", so we were confident the Mazda RX-8 WB02 was up to the task we want to use it for.

My honest opinion on the "CZ" improvements / calibrations... Well, I shouldn't really post, but the term "FUD" does ring a bell. I have not motive to profit from an "adjuster".

And the device is a Lambda sensor. It doesn't matter what fuel is used. Lambda is Lambda. If you researched how one works you would understand. And even if was it not "linear" across the whole range, out tuning efforts are restricted to a very narrow area - max power.

Nuff said!

Cheers,
Hymee.

 

Sounds more like it.

What is FUD?

Fabrice

 

fine, i give up... everyone that ran into pinging problems tuning with uncorrected numbers had no idea what they were doing. If you wish to believe that its fine with me.

 

I'll let someone else answer

Cheers,
Hymee.

 

Well HUD is Heads up Display... so is FUD Foots up Display?

I Fear some Uncertainty and Doubt about that one?

 

But did they tune with Knock Retard?

Did they tune AFR's based on an estimate of the stoich value of the fuel?

Did they tune to the "correct" AFR / Lambda for a rotary engine?

Did they .....

Cheers,
Hymee.

 

Toe prints on the windshield means... You had a nice weekend

 

Someone could make big bucks writing the definitive "Tuning RX8s for Dummies" book. Unfortunately I'm in the customer category and not the author category!

Hymee, I’m looking forward to your product and starting the process of really understanding my motor. Like most, I’m convinced there is untapped potential to be unlocked by tuning.