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Gents,

I’ve been tuning with Advantage III for a little bit now, and a few things have kind of puzzled me. I’m tuning off of calibration 04510055AE.

When you’re looking at the Air Charge Multiplier As Function of Inlet Air Temp and Flow Compensation tables under Speed Density, it lists the temperatures in degrees C, but they range from -40 to 120 and -40 to 100 respectively. Are these temperatures really in degrees F and SCT just has the wrong temperature descriptive or are they really in degrees C? IF it really is in degrees C, there’s not going to be many people driving the car if it’s 100 C outside, so I don’t even understand why these values would be in the calibration…lol.

Also, when you’re looking at the Throttle Body Flow table under Speed Density, it shows the voltage range going up to ~12 Volts. Shouldn’t this only go up to ~5V for the TPS sensor?
 

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Honestly it doesn't matter what the limits are within your tables as long as you are inside the upper and lower bounds.

Although I do not have a SCT the principles remain the same. For instance with my EMS it has the ability to output data in a serial format. Looking at my settings I have a range of 0 - 249.996437 percentage of injector duty cycle. Or how about RPMs. I can go from 0 - 25599.60938. I don't know any cars that do 25k+ RPMs.

Basically when the flash tool is made they incorporate a range of settings that your ideal car will fit in. Getting it exactly down to the upper and lower bounds is quite difficult and can be a waste of space since there will be bits/bytes of machine code and data memory left empty. It is easier to make tables and variables with an exact number of bits/bytes that your range fits in and just interpolate the rest to sometimes have a huge maximum and minimum.

For the temperature ranges I would say that C is correct. 120F is too small as I have seen intake temps higher than that in less than ideal setups. How hot does it get in AZ or other places like that? 110F maybe? Add the confines of a hot ass engine bay and you could easily exceed 120F which could put the calculations in la-la land as it could overrun its code/variable space and go haywire.

And for the TPS our vehicles do 0-5VDC. Some may or may not do the same. If they wrote the code specific for 0-5VDC then SCT might lose the "universality" of their code and might have to create a firmware for each vehicle specifically which is a poor coding philosophy for a company that targets numerous platforms.

HTH
 
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