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      12-22-2007, 07:53 AM   #189
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Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

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Originally Posted by footie View Post

I must say that ruff does give you a really hard time and like you said regardless of what answers you give in return. I actually think the times you have given for the M-DCT is as good as we can get given that there is currently no actual data and spec to work with.

It's doubtful that BMW will alter the character of the M3 engine to this new gearbox though in fairness it would be a very simple thing to done and might be beneficial.

Will the M3 with M-DCT match either the C63 or IS-F to 150mph, definitely NO against the C63, it extra power and way more torque will always win in such situations. As for the IS-F, that's a trickier one to answer, I reckon the IS-F will win but by the smallest of margins.

On the track, sorry but there is no substitute for the engineering in the M3.
I'm sure that they won't touch the engine as well.

I think the 0-150 (and other) times will look something like this for M3 M-DCT, IS-F, C63:

To clarify key assumptions (in case ruff is reading ). Almost everything is "default" in the sims except shift times. For the M3 and M3 M-DCT (.25 and .03 s respectively), for both the MB and IS-F I have assumed very fast shifting, high performance, low loss automatics (not as low loss as a std. MT though). For example Lexus claims the IS-F will shift in 100ms but I made up a reasonable engagement time to match (not very significant anyway). Lastly with the AMG I have used some known acceleration numbers to establish the under-rating of the car and then just ran with those more realistic figures for hp and tq.

Also relevant:Simulation results at high speeds require detailed frontal area and drag figures, the latter of which is probably fudged quite a bit. For this reason the 150 mph times are likely less accurate than the 100 mph or less figures. What should be the most accurate is their order and relative differences.

Last but not least BMW may have chosen different optimization goals than mine for the DCT gearing and if so there is no reason the IRL results could be expected to match my sims. However, that being said, I think I chose very reasonable gear optimization of simply asking for a bit more performance "everywhere".
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