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Load scale units


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Hi Guys,

Probably a super obvious and straight forward answer but i have searched everywhere and have not found a confident answer to this.

Are the Load values on the x-axis of the Fuel Base Cold(ECT,Load) and the Borderline Knock(RPM,Load) tables simply percentage as one would expect?  The reason i ask is that the Load on the Fuel table goes up to 1.5 inferring 150% and the BLK goes to 200%.  If it is percentage why does it go so high? Are there circumstances where load can get this high?

Thanks and keep up the great work. Truly the best money I've spent.

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Load = airmass / maximum cylinder airmass at atmospheric pressure. 

So in an NA car technically the maximum air mass you can get is when vacuum drops to zero (eg atmospheric air pressure) which would be a load of 1.0

In a turbo charged vehicle you can go above atmospheric air pressure and hence load goes above 1.0

Eg atmospheric air pressure is 101kpa so at a boost pressure of 101kpa (total pressure = 202kpa) you would have a load of 2.0

101kpa is 14.7 psi of boost 

If you run 30psi (206kpa) your load would be 206 + 101 / 101 = 3.0 load etc 

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Thanks for clearing that up!

So my next question. Do the load readings that’s come out of the obd2 connector (0-100%) relate to the load on the tables?  


Just having a bit of trouble pin pointing cells. Slowly getting there. TPS by AD count is another one. I’ve read that 580 counts is WOT. But yeah, matching that to tps% requires bit of extrapolation/ hope that it’s actually 580.

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The load values that come out of the OBD2 are pegged at 100% like you say. The load values that are on the Spark axis etc are calculated as per @Roland@pcmtec post. See if you can log something like Air Load. You really need to log the DMR value Load to get that accurately but other vendors think air load is good enough. Air load is usually something along the lines of MAP reading/Barometric pressure and is reasonably close to load.

Throttle percentage, from what I have seen, comes from AD count /1024 in other products. So WOT in your example would be 580/1024 or about 57%.


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