New sim code

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Looking at the telemetry showed that the old code is running with a wrong weight distribution for the 350Z 47/53 while the correct one in the new sim(with substeps) is 53/47. Which also explains the grip issues. After feeding the same car data into both sims the new one is actually more stable. I need to test both sims with a few more cars but I hope for similar outcomes so that the new code can be "re-reverted".

Just for fun a snippet of engine + wheel friction torques of both sims:

old(10 substeps):

47.8968
50.1497 w -129.877 -134.324 -320.931 -321.354
49.4877 w 129.619 134.153 331.809 332.474
51.7235 w -128.938 -133.477 -331.263 -331.948
50.9522 w 129.224 133.975 341.636 342.303
53.1722 w -128.478 -133.159 -341.065 -341.664
52.2995 w 128.68 133.542 350.682 351.343
54.5049 w -127.885 -132.424 -350.122 -350.44
53.5393 w 128.573 133.515 359.017 359.649
55.7313 w -128.154 -132.91 -358.943 -359.382
54.6771 w 128.205 133.183 366.662 367.278
57.0

new (10 substeps):

47.4184
51.6482 w -50.2377 -47.6083 -355.091 -349.725
51.6482 w 43.8085 43.861 -216.299 -210.362
51.6482 w -13.8166 -12.9071 -305.447 -295.342
51.6482 w 18.1025 17.5345 -256.7 -249.294
51.6482 w 2.99534 -0.33031 -274.576 -281.526
51.6482 w 6.95784 10.0478 -270.359 -263.997
51.6482 w 4.61346 1.61523 -272.124 -278.665
51.6482 w 12.4322 15.5022 -262.111 -255.427
51.6482 w -7.19947 -10.3066 -290.224 -296.928
51.6482 w 11.8116 14.9467 -289.785 -127.92
55.8798

The engine torque is updated every full step in the new sim. Please note the oscillations in the old sim which have been one of the reasons for the rewrite and are greatly reduced in the new implementation. Ideally we would want an even more smooth behavior but that would require running the complete sim at high frequency.