acc pump

[beefcake]

thanks guys again but i already understand everything about the absolute pressures as i was also talking to two of the WA based dealears about it today and i mentioned that theory but they were still looking into it for me , so basically i have to now dump my old school brain of reading gauge pressures , and uptake the absolute idea in my head
when you say channel Mr holmz do you mean making a new channel in the i2 chart to read it, or elsewhere

Im sure my answers back from the dealer will reflect your ideas for me in this thread, thanks again guys

[Holmz]

The math(s) channel in the i2 just to read it as you are a costumed to doing.

[beefcake]

Ok im not too sure if you guys understood where i was coming from or what i was trying to ask, but i showed my ecu settings to mr motec in my state and he agrees that my car has been tuned correctly, it has negative vac settings under 100 kpa , so its not a ecu fault,
Now we then looked at my i2 log, and yes he agrees that its reading positive only , he agrees that its idling and showing 10 psi boost, and full load is 35 .
But its nothing to do with the brand of map sensor i have , its a simple selection in the i2 somewhere that i have to learn for myself to make the data read "guage" pressure , its not in the pull up box that you right click on either, as when i change the setting to psi or absolute psi it still reads exactly the same
Basically i have to either figure the setting out so the downloaded data can then read correctly or hand my laptop in and along with cash to have it tickled with to make it work

Ill keep you posted

[beefcake]

my brain hurts im not sure if i did what the guy hinted to me to try , but i just did what holmz mentioned
I took ages to find and figure out how to sort a maths table , got the settings sorted then minused 101 from the kpa setting and chazam it works
thanks for listening to my ramblings again

[Scott@FP]

You can't use the default selection PSI (Gauge) in the main I2 to read +/-, you must write a math, for instance kpaA * 14.5 -14.5 for PSI gauge with zero at 100 KpaA. 1 kpa = .145 PSI, but where the proper place to set your "zero" reference is up for debate. 100 kpaA is lower than a STD atmosphere by most definitions.

[beefcake]

correct, thats what ive done above, and 101 kpa is close enough to what the rest of the world call atmosphere technical so its good enough for me and it works perfect on my i2 setting .
The only debate i have is why doesnt motec have this as a simple selection choice instead of having to set up a maths bending table channel

im not too nerdy on what decimal it needs to be , as long as i can check my boost curve from the runs then im happy , im only worried about max boost settings, as i have to be careful of overboost situations being a rotary

[Holmz]

You can't use the default selection PSI (Gauge) in the main I2 to read +/-, you must write a math, for instance kpaA * 14.5 -14.5 for PSI gauge with zero at 100 KpaA. 1 kpa = .145 PSI, but where the proper place to set your "zero" reference is up for debate. 100 kpaA is lower than a STD atmosphere by most definitions.

If you have a MAP type sensor in the airbox then the highest value there should be around idle, and lower values should not be too far off unless the filter is blocked.
One could probably do a math(s) and get the max value there and use that for the number to subtract by.
That would make the gauge read right at sea level and everywhere else.


Mr Beefcake - can you show what you out into the maths equation?
Would be a great way to tie the thread up!

[beefcake]

no worries mate i just simply put -101 in and it now shows all my logs exactly what i wish to see , it also matches my dyno logs as well , to a degree as dyno is not the same as track

I just made a new channel , and from the kpa original setting i subtracted that -101 figure from it ,it then shows what i chose to display ie psi kpa bar , all in my "gauge" style readings
The original ecu setting being kpa absolute , and i set the maths channel to display psi , so in the large box in the maths channel i just typed -101 after the original kpa setting
Ive also kept the original kpa chanell as well, dunno why but you guys are spooking me with your cyclone talk , spose in due time i will learn how it all relates

Im racing at the track tomorrow , its our 40th annual western nationals , its the biggest drag event in our state , im also excited as i figured out how to make a real two step boost building setup, now instead of just relying on the dual rpm to limit my launch revs , i have a overrun boost/anti lag setup as well , it now bangs and flames it butt off and actually gets me 12 psi on the limiter before launching
Ill see if i can break something in my driveline for you guys

[Scott@FP]

Sorry, should read kpaA * .145 - 14.5 for kpaA to PSI gauge, with zero at 100 kpaA.

I guess to get it back to using 101.3 kpaA as a std atmosphere zero you would use kpaA * .145 - 14.6885

[Blu302]

You could change the sensor calibration table on the input setup. Use a custom table instead of a predefined one and do the maths on each cell individually. Then it will output the numbers you want by default with idle giving minus numbers(eg -30Kpa).

Hope that helps