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      01-06-2020, 09:22 PM   #102
CanAutM3
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Quote:
Originally Posted by Humdizzle View Post
true. but it does seem more abrupt in the DCT no?

in the manual you are getting the gear you want on the downshift.. car revs up.. then you let the clutch out... then you apply the throttle.. the turbos spool and gradually build torque.

It seems though that with the DCT this all happens very fast while the person is still on the throttle downshifting between gears... and you go from 100 ft/lbs of torque @ 1500rpm to 400 ft/lbs at 5000rpm almost instantly. similar to how a hard launch with boost off the line is also hard on the drivetrain.
Why would it be more abrupt on a DCT ? It does exactly the same as on a 6MT: open the clutch, rev-up the engine and release the clutch. Even if the driver keeps the throttle pedal floored, it is the ECU that adjusts the actual throttle opening for the downshift. Also, on a well executed MT downshift for acceleration, the throttle should not be released.

Further, IMO, it is not the amount of torque produced that will get the crank hub to spin, but rather how quickly the engine is accelerated in revs. As long as it is the engine itself (with a stock tune) that increases its own revs, and not the drive wheels that do it, there is no risk of spinning the crank hub.

As a tidbit, the original S55 tune makes ~330lb-ft of torque at 1500RPM. As a second tidbit, a ft-lb is a unit of energy, not torque; torque is measured in lb-ft .
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Last edited by CanAutM3; 01-07-2020 at 05:13 AM..
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