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      05-28-2014, 06:06 AM   #110
Sered
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Drives: 08 E90 335i
Join Date: Apr 2012
Location: Melbourne, FL

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Quote:
Originally Posted by bradleyland View Post
I don't blame you one bit for choosing 6MT. I actually tried to find a 6MT car, but ended up with DCT.

Never the less, staying in the power band is only one advantage of DCT. The other advantage is the speed of the shifts, and AFAIK, this is the primary reason DCT shaves time off numbers like 0-60 time. Interestingly, the faster you go 0-60, the more meaningful these savings are.
Yes, I know that. Which is why I qualified my statement twice when I said 'some' of the advantage.

Quote:
Originally Posted by regular guy View Post
These are fastest 60-130's on record for a "normal" (non nitrous, non built-motor) supercharged E9x M3:
DCT: 6.46 seconds
6MT: 7.52 seconds
Difference: 1.06 seconds

CarTest (physics based automotive simulator) gives the following results for the same car, same supercharger kit, same road conditions based on actual dyno charts. The only difference is DCT vs. 6MT.

CarTest DCT: 7.06 seconds
CarTest 6MT: 8.25 seconds
Difference: 1.19 seconds.

You can see CarTest matches real world results pretty well. Most people would consider 1+ second difference quite significant.
Again, read what I said. Stock and S/C cars tend to have the same kind of powerband, peak hp at max rpm with a steady climb up to it. Cars with big V8s or turbo 6s like the N54 do not do this. They make peak power and then scale off a bit. The effect is they hold peak power for longer which increases their average power over an rpm band. The N54 rarely falls outside of its powerband from shift to shift. The S65 on the other hand, falls WAY outside of it (much moreso the 6MT though as the DCT's extra gear and shift speed helps mitigate this), especially on the 1-2 and 2-3 shift.

Your example shows stock and S/C cars which doesn't begin to address the argument I'm making. The difference between 6MT and DCT on the N54 platform isn't as huge as it is on the S65 platform. And the 5.0 generally can trap as well as a stock DCT M3 though usually a mph off or two (despite making similar peak power stock).
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