mapper Posted January 15, 2015 Report Share Posted January 15, 2015 HiÂ What does the closed loop boost controll refering to? MAP or MGP? I saw in the setup guide that the older firmware had a option to choise Target mode. Why I'm asking: I made some turbo compressor ratio calculation and realised that there will be big pressure ratio differences if the closed loop referce to MAP. That means you will have more boost on higher altitude (less baro pressure).Â turbo compressor ratio is calculated as follow:Â Â compressor outlet pressure / compressor inlet pressure as a example at sealevel: baro=100kpa absolut, boost = 200kpa boost pressure Pr1 = (100kpa+200kpa) / 100kpa Â = Â 3.0 lets assume we drive on a very high mountain: case 1 MGP: baro = 70kpa, boost pressure if boost control refers to Â MGP = 200kpa Pr2 = (70kpa+200kpa) / 70kpaÂ =Â 3.86 Case 2 MAP: baro=70kpa, boost pressure if boost control refers to MAP = 230kpa Pr3 = (70kpa+230kpa) / 70kpaÂ =Â 4.29 Â As you can see from the calculation, we have more boost with a MAP referenced system and the pressure ratio differ alot more than a MGP system. The big increase in pressure ratio, means that you can fall well out of your compressor efficiency map. So in my eyes MGP referred system would make more sense. Otherwise there should be a baro compensation map.Â If I'm missing something, please let me know.Â Quote Link to comment Share on other sites More sharing options...
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