RomRaider

06 wrx

MAPpsia = (12.08548*LOAD)+.658659

Wow. That was fast.



Can you tell me what the equation is for the 05 LGT? Thanks!

http://www.xpttuning.com/osecuroms/view ... 37b595179f

05 usdm LGT (A2WC510N):
MAPpsia = (11.69798548*load)+1.523592421

07 usdm STi (A2UG000J):
MAPpsia = (10.45230811*load)+1.801977918

06 usdm WRX (A8DH200X)
MAPpsia = (12.08548125*load)+.658658728

Also it averages between the current calculated value and the previous one.

Any chance someone here can remove the ECU limiter of 23 (app) psi so when corrected pressure is logged it doesn't cap itself?

That would be cool!

If you download the latest logger definitions, you can log absolute pressure with no limit by logging the extended parameter 'manifold absolute pressure (direct)*'.

Thanks. I know that can be done.

I use COBB's software most of the time for logging, mostly because of convenience, and because it accepts my WBO2 signal.

It would be nice to remove the limiter, if it can be done.

The scalers that limit the log items can technically be tweaked, but then you also need to change formula/value equation in the logger XML for the ROM. Then it would only log correctly on modified ROMs...

Say, MAP as logged by SSM is an 8 bit value, so what you're doing is mapping the values
0,1,2,3,4,5,..., 252, 253, 254, 255
onto the values(approx)
-15psi to +18.6psi
So 0 = -15, and 255 = +18.6

This is a simple first order equation
psi = k*x + c
where x is the 8bit integer (0-255), k is gradient/slope, c is offset. K and C are effectively defined by the logger XML in the "value =" field. They match the values of an internal storage routine that copies the raw ECU value into a separate location for use by SSM. You can change the internal storage routine AND your logger XML so the 0-255 now maps to whatever you want, with only a practical limit of the sensor itself.

I think it would make sense to maybe tweak this open a bit once Enguinity starts popping out tweaked ROMs with LC, SD, realtime, etc. The CALID really should be changed anyway to purposely break compatibility, and this would allow both the logger and internal SSM value copy routines to be tweaked to allow higher MAP to be logged.

I don't ever expect a workaround for the Cobb. You'd have to ask them about it.

There's no limiter, per se. The variable for MAP is clipped in the conversion for SSM logging which limits its range. Which is why I added the ability to directly monitor the MAP variable in the RomRaider logger defs so there would be no limit (as well as being slightly more accurate).

So, if you have to use Cobb's logger then you should bug Cobb to add the same capability.

I can follow what you are saying freon, but it is a bit over my head.

I thought it may have been like the 300 g/s limit in 32 bit ECUs. I guess it can't be because my ECU still adjusts boost gains (or integrals) even when it is beyond the boost cap, whereas the ECU if left at 300 g/s cap does not fuel beyond that point.

Thanks anyways.

It is MUCH simplier to just log the actual MAP variable via a SSM read as has already been done with the RomRaider logger definitions - no loss of accuracy and no effective limit. Getting it to work with Cobb's logger is pointless as a RamTune setup is not going to be compatible with Cobb's real-time tuning and their logger is only available with ST, so it would be a waste of time.

Well, the advantage is you only have to query (usually) 1 byte, not 4 in the 32bit ECU for the floating point direct values. Querying several floating point values really starts to slow logging speed down. Floating point precision is way overkill for most values.

True. Not really an issue for the 16-bit ecus as it is only a 16-bit value, but I see what you mean.

I think an easier and more elegant solution, though, would be to use one of the unused SSM ids for the new parameter. Then simply update the ecu init to enable that ID and then add it to the logger defs. This would be better than changing the ecu id, which would not work as you cannot define separate standard SSM parameters based on ecu id (only extended parameters that rely on a SSM read).

That's a good idea. The "copy for SSM use" subroutine calls are already there as well and would be easy to implement.

merchgod, can we move this thread to ECU Analysis? It seems to have information about how the ecu handles data (such as the MAP Sensor and the failsafe logic).

I might be a little late and on a little bit of a tangent, but isnt the TurboXS MAP sensor a 4 bar map sensor, good up to ~45 psi? It was recommended that for boost levels under 30 psi that I instead use a GM 3 bar map sensor so I will have more resolution in the voltage.

With that said, can someone tell me the proper procedure to calibrate this? I saw the calculations explained earlier in this thread which I can use, do I just need to get 2 points of boost and voltage to work off of? Is it an option to log MAP voltage through RomRaider?

Thanks for all the help... we only tuned my Green to 21 psi for now but I'm looking to have the option to go a bit higher especially with my Aquamist setup .