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      11-27-2013, 02:27 AM   #86
swamp2
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Drives: E92 M3
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Quote:
Originally Posted by JoeFromPA View Post
Swamp - I think your 0-60 time and quarter mile ranges are way too optimistic on the the aggressive end of things.

Vehicles getting 0-60 in 3.4-3.6 seconds are doing it by AWD+launch control, gearing to hit it in 1st gear, and/or a lot more power.

I've followed your analyses closely and love a lot of them. However, on the acceleration front, your linked analysis appears to favor using linear increases to acceleration times when it's truly exponentially harder to drop a tenth of a second at these stages.
Thanks.

Can you expand on the important bold part above? I don't understand that at all.

My estimates for all performance results in the new M4 are based on CarTest physics based vehicle performance simulation software. It generally handles vehicle launch, wheel spin and the differences between friction coefficients for spinning vs. non-spinning conditions all quite well. It it a perfect launch algorithm, certainly not but the essence of the physics is captured. Now why have I reported a range of numbers? Again that was from a simple bracketing approach allowing for reasonable estimates of the uncertainties associated with underrating and vehicle weight.

The current M3 has already done a 3.9 s 0-60 (with standard US 1 foot roll out). What makes you think that with a significantly improved power to weight ratio, significantly more power at low rpm, very likely a new improved tire and also very likely improved LC software that at least a couple tenths better than that won't occur? Look I am not saying that your average everyday M4 driver will consistently get 3.5 second 0-60 runs. However, I am also virtually guaranteeing we will see one or more magazines run 3.8 s or less.

Not entirely directed at you but: 0-60 certainly is not the "end all be all" or the most important metric I care about. However, good results do show a combination of good engineering and design all working together, engine, transmission, differential, software, chassis, tires, etc (and of course driver). Some other metrics indeed are better at "displaying" the true power to weight of the car (and not much else...).
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