I was afraid my tuner had tuned in close loop and true enough he did. He even tuned it up to 5V(airflow). So right now, I have actually taken over the tuning. First thing I did was reset the ecu so that ltftwas zero. Then I drove it for a couple of days without any map. It build a ltft of -10%.

I also tested at which particular airflow voltage would 30% throttle be. I then only tune at 3V airflow which is about 30% throttle and 3000rpm and above. Do let me know if it is wrong?

 

hmmmmm - try not tuning below 4000 rpm - that will be safer .
Not sure if you can relate airflow back to % throttle . Don't you have a way to measure % throttle ?

 

Yes, under the emu airflow correction map. There is a choice of tuning using rpm against throttle position or rpm against airflow voltage. I was told that airflow voltage would be better and more accurate then throttle position as throttle position is more often use for racing where it is mostly at 100% throttle.

Can anyone tell me if it is true?

 

It is true.
Airflow voltage is an actual load measurement.
Can you send me a copy of your MAPs so I know what we are discussing here?
You can send it right to my e-mail.

jeff at mazdamaniac dot com. Change the "at" to "@", the "dot" to"." and ditch the spaces!
Take that SPAM-bots!

 

Sent!

 

MM - I have tried to figure out what determines the exact switch over point for open/closed loop . Is it directly related to airflow voltage ? If so do you know what voltage the switch point is ?

I'm pretty sure my scanalyser will only measure air flow in kg/s which must take in to account temp. as well as airflow . Perhaps a certain kg/s is the trigger ?

 

I've never attempted to find the exact switch-over point.
I'm not sure it would be obvious except to have access to that flag in the CANbus scan, which I don't have since the CanScan doesn't show that (at least not in the non-.NET versions).
That said, I haven't really needed to know that information since I'm only concerned with high load for tuning purposes and I can force open-loop by shutting off the WBO2S.

 

MM, how u scale up the injectors? did u receive the map i sent u?

 

Go to this window:



and change the injector values like this:

 

Thanks! Will try it and see if it decreases my ltft. So I just need to follow your input values? Cause I do not know the cc of the primary injectors and the secondary ones as well. IS it right to sae i need to retune once i scale up the injectors?

Another thing, there is a NVCS map. Is the boomslang harness wired to use it? I remb reading somewhere it can be used to forced open loop?

 

You will want to reset your PCM after changing these values to reset the LTFT.
The actual injector values on the RX-8 are 290cc, 380cc & 380cc.
By telling the EMU that you have slightly increased the size of the primaries, it will scale them down a bit which will trim the mix lean overall and reduce the LTFT subtraction.

To use the NVCS for forced open-loop, you need the dongle I was talking about earlier.

 

I happen to have 3 dongles with me but all uninstall. It came off a greddy turbo kit. Can I use those dongles or do I have to get emu specific dongles?

 

The O2 sensor dongle will work. It has two light-blue wires, a red wire and (I think) a yellow wire.

 

I still have not increased injector sizing on emu yet but i did a couple of runs to see my afr and also the LTFT.

I read in one of your post that under WOT it is suppose to go to 0 but idle is -12%. But for me it only drops to -10 to -12% under WOT.

To where do I wired the dongle to?

 

What afr should I be looking at from 3000rpm to 5000rpm? Above that I tune for 13.7 - 13.2afr. I tried to scale up the injectors but then at 6500rpm my car felt like there is a rope tugging it back. So I now retune it without scaling up the injectors. My ltft at WOT is -9.6% and -13.6% at idle.

 

Yeah, you have to re-tune if you scale the injectors.
That just fixes the LTFT.
I'd shoot for the same 13:1 or so across the board with 12.5:1 or so around 5500.

 

you'll save yourself alot of grief if you tune only over 6,000 rpms... below that (at least on my car) the afr is around 12.5 to 13 anyway so there is little point in putting yourself in a position to continually battle fuel trims

 

out of curiousity, can smt6 from perfect power be used for rx8?

 

In MM's 03_05_07.EM2 map the lag time is set at 0.02, yet in post #88 he states 0.20...

 

.2 is a typo. its .02.
Sorry for the confusion.

 

MM, could you tell me why 12.5:1 around 5500rpm? Is that the point tat tends to piing?

 

Yes. between 5500 and 6700 is the torque peak, which is where pressure levels inside the motor are highest.

 

I got a very stupid question but I feel I have to ask.

Our first O2 sensor is wideband. So is there still a need to use an external O2 wideband to read the afr? I tried using the car's sensor and compare it with the external wideband. The external wideband reads much leaner then wat the car's O2 reads. Which is more accurate?

 

That all depends.
First of all, if you after market wide band is not installed before your CAT, it will read lean.
Second, if you intend to use any sort of "spoofing" on your OEM WBO2S, you will need the after market unit because the OEM unit will not be responding during the periods when you are forcing the tuning into open loop.