10-29-2022, 02:24 PM | #1 |
Car'a'carn
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Thoughts on how the power is limited
For the M3/4 I found this
From Car and Driver "As a refresher, the standard $70,895 M3 comes only with a six-speed stick and produces 473 horsepower and 406 pound-feet of torque from a wonderfully smooth twin-turbo 3.0-liter inline-six. Opting for the $2900 Competition upgrade, however, necessitates the fitment of an eight-speed automatic, yet brings more turbo boost (24.7 psi versus 18.9) and an additional 30 ponies and 73 pound-feet." Do you think they just further reduced the boost? Or do you think they remapped the ecu |
10-29-2022, 02:36 PM | #2 |
Captain
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Remapping the ecu = reducing the boost
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T_U_D6698.00 ronin130131067.00 |
10-29-2022, 02:50 PM | #3 |
Car'a'carn
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Yeah no.
So getting a boost controller is remmaping the ECU? Yes I get that the turbo wastegate is electronically controlled by the ECU. But obviously I’m not talking about that. I’m asking if they’ve done exactly the same thing which was to limit the boost and no other changes. |
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10-29-2022, 03:45 PM | #4 | |
Second Lieutenant
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Quote:
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10-29-2022, 05:02 PM | #5 |
Colonel
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I'm actually more surprised that 5+ more pounds of boost only netted 30 HP. I had read somewhere that the dynos of comp and non-comp were similar torque-wise so I assumed the boost delta was very small between the 2.
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10-30-2022, 10:08 AM | #6 |
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The car and driver article is wrong and misleading. Not sure where they came up with those figures, but newer BMW engines (S58/B58) don't work on static boost tables. I have an M4 Comp xdrive and have seen the requested boost vary from <16 all the way to 21+ based on conditions. Never ever have i seen anywhere near 25. JB4 map 4 which suggests E30 is an absolute value of 25 psi.
IAT seems to have the biggest influence as it will run lower boost and higher ignition advance with lower IAT, and the boost gets higher and timing lower as IATs increase. Regardless, yes the difference in the 3 engines will be ECU/DME mapping. |
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