Hello folks,

Since the other thread is getting a bit side tracked, I want to start a thread that deals with only technical issues and questions. To start off, I am currently using the targeting table on the Hydra. The AFR Target table. I have enabled the "Wideband target table" in the closed loop tab in settings. Also I have enabled long term learning. my idle and cruise are spot on with the target table of 14.7 to 13 depending. Therefore I was assuming that the targeting table is working.

But I have not used/touched the auto tuning feature. Has anyone used it and does it change values in your main fuel map? If so, are you required to "Download" this to the ECU after? If not, how does it work.

My assumption for the targeting table is that the "AFR target" table with what I mentioned above enabled, will not change your fuel map, but will change the output in MS to your injector cycle. ie when i have 7 ms it will change to 8 ms to make it richer if need be. This is transmitted to a reading to STT on the display (I believe) as the short term (fuel) trim? There is no mention in the documentation... :furious: :)

I have not used the LTT The long term trim table since I am doing baby steps. I use the information from the logs to trim my own fuel map. (doing it the long way, but I like to have the foundation first).

Now why I am asking is that on the MR2 forums there is a post stating that you need to select both the autotune and the wideband target table to autotune. my second question is what happens if you select auto tune, wide target table AND long term learning....

I believe that the autotune feature doesn't change the values in main fuel map, you're required to save this to your laptop if you want to use this map for the ecu. You may want to smooth the map out in certain areas and then upload it back to the ecu. This is second-hand information from Phil.

?

this means that it changes the values in the fuel map on a loaded map when in diagnostic mode, but will not change the fuel map on the ECU memory chip correct?

then you need to save the software map and then send it back to the ecu?

thanks btw. any info on LTT (Long term trim) I have no idea how this works...

Hok,

To use the AutoTune feature you enable "Closed Loop," "AutoTune with DRQ," and select "Wideband Target Table" but you do not enable "Long Term Trim." While in AutoTune mode you will see changes to your AFR but you will not see changes in the fuel map until you "upload" from the Hydra. At this point you will see the changes to your fuel map. To make these changes permanent you must then "download" this to the Hydra. The reason you do not enable “Long Term Trim” while in “AutoTune” is because those are temporary changes that are lost when the Hydra is powered down.

It’s also good tuning practice to smooth in the areas that were not touched by the AutoTune feature. This will be fairly obvious to see.

Thanks,
Phil
www.elementtuning.com

Thanks for the post...

this is ironic... the "long term trim" is temporary when in autotune... can I assume that the "long term trim" stays when selected by itself, when not coupled with Autotune?

Thanks again

Well I can't say for sure, but 'yes' to your question. From what I can tell by poking around with the software, and talking to Phil, Autotune is a tuning mode, once 'tuned' you have set the upper and lower limits of correction. Locking those 'tuned' values in requires the down/upload to the ECU. Once set, your car will still "learn" but only within the boundaries set in the tuning mode. Phil feel free to negate.

Let me clarify the terminology.

Short Term Trim: Constantly makes minor adjustments of fueling to reach 14.7 AFR during a drive cycle under light load conditions while using the factory 02 sensor.
Long Term Trim: Makes major long term change to reach 14.7 AFR during a drive cycle under light load conditions while using the factory 02 sensor.

So for instance if under a given RPM and a given load your fuel map is off by -7%, the “LTT” will add +7% more fuel. The “STT” will make minor adjustments as needed to maintain 14.7 AFR if +7% is no longer the appropriate adjustment. Fuel trims are defined during a given drive cycle but once the car is turned off both the “STT” and the “LTT” are set back to zero. You can use the “LTT” table (logs trims) to manually correct the fuel map under light load.

If you have purchased the WB/AutoTune option you can use your “AFR Target” table to define the AFR under light load conditions instead of being limited to 14.7 AFR.

The “AutoTune” feature makes permanent fuel corrections to all load ranges defined in your “Closed Loop” settings. The AFR target is set in the “AFR Target” table. You should turn off “Long Term Trim” while using “AutoTune” as these temporary changes will inhibit the permanent tuning process (too many chefs in the kitchen so to speak).

Phil
www.elementtuning.com

Short Term Trim:


Phil Said trim!!!! LOL :lol: (short term trim is like one night stand trim) :lol:

Phil are the STI hydras out and in stock?

I just cant get the utec right. I may take the plunge come down from NJ and buy and have you tune the hydra, can this be done all in a days work?

sweet... its much clearer now...


Also I wanted to add that modded WRX injectors work well with the hydra... at about 20 psi on the GT30 I get about 78% duty cycle... the pinks I had 98% at 20 psi and 102% at 22 psi

anyone getting minus temperature readings when you just start the car on the ATS..... I get this for the first while then its like it "warms" up and then reads normal...

Hok,

The factory MAF sensor on the RS is notorious for failing. Are you using the factory MAF sensor for your temperature readings or an aftermarket IAT (GM)?

We don't see this problem while using the factory MAF sensors on the WRX or STI .

Phil
www.elementtuning.com

I'm using the GM one... i think it is this part number GM 25036751

but it seems to be flaky with another owner here. I don't have the MAF connected.

any suggestions? Thanks again.

I've been tuning with the factory MAF sensor for IAT readings and it works great. I have not tested the GM IAT because I've had such good luck with the factory MAF sensors.

You'll have to contact Hydra directly about the GM IAT since I have not tested one nor have I ever tuned an RS.

Thanks,
Phil
www.elementtuning.com

mmm maybe i will plug the maf back in...

thanks

Ooooh! I finally have a technical question :-)

On my 02 WRX, the stock ECU stops listening to the knock sensor above 5000 or so RPM's. I'm not 100% sure why this is, but does the Hydra have the same limitation or can it detect and react to knock at all rpms?

The Element Hydra has sixteen points of knock threshold adjustment for knock amplitude. This allows you to adjust the sensitivity of the knock system over 16 ranges of RPM (entire range) The amount of timing pulled per knock account, the maximum retard, and additional fuel compensation is user defined.

If large amounts of knock are recorded, a backup spark map can be triggered to come online for safety.

http://www.elementtuning.com/images/ems/image8.jpg

Thanks,
Phil
www.elementtuning.com

http://forums.nasioc.com/forums/showthread.php?t=637088

bump for future reference.

...xxxxx