DCT question: downshifting at high speed and rpm

M3Dreams · 10-07-2011, 04:41 PM

For all DCT owners only:

Have you experienced a slight clutch slippage scenario when downshifting at high speed/rpm. By that I mean downshifting from 5th to 4th, occassionaly 4th to 3rd, around 70 mph and engine revving in the 4-5K range. When I hit the downshift paddle and floor the gas pedal simultaneously, the car exhibits what seems like a slight clutch slippage, and a slower response and then once it has switched gears, the tranny hooks up just fine and the car takes off. Now, if I do the same thing without pressing the gas pedal, the tranny, in what seems to be a relatively slower response still, switches gear but does not seem to clutch slip. Once the gear has switched, if you punch the gas, the car takes off with immediate action. I was wondering if anyone else has experienced this. In case you are wondering, my car has only 9.5K miles and has never been launched or abused in a manner that I could say would have worn out the clutches.

Apart from learning new things about this tranny and its different ways of handling certain scenarios, I love every bit of it. Its lightning quick upshifts and wonderfully executed downshift blips are without any parallel. It is truly the best of both worlds, i.e. crawling traffic jam world, and track use world, and satisfies my needs as a daily driver.

Thanks for your input.

llis · 10-07-2011, 05:25 PM

I think it depends on your driving at the moment, in part. The double clutch system works fast by having the next gear ready to engage, but if you downshift when the DCT is expecting upshift, or upshift when the system is expecting downshift, you get a delay, more like a regular automatic transmission might. At least that's what it seems like to me.

But all that's about slight delay. I can't say I've felt actual slippage, like a clutch going out.

10-07-2011, 04:41 PM	#1
M3Dreams Private First Class 89 Rep 166 Posts Drives: F83,F30340,E82135,E90M3,E46330 Join Date: Oct 2010 Location: Minneapolis, MN iTrader: (4)	DCT question: downshifting at high speed and rpm For all DCT owners only: Have you experienced a slight clutch slippage scenario when downshifting at high speed/rpm. By that I mean downshifting from 5th to 4th, occassionaly 4th to 3rd, around 70 mph and engine revving in the 4-5K range. When I hit the downshift paddle and floor the gas pedal simultaneously, the car exhibits what seems like a slight clutch slippage, and a slower response and then once it has switched gears, the tranny hooks up just fine and the car takes off. Now, if I do the same thing without pressing the gas pedal, the tranny, in what seems to be a relatively slower response still, switches gear but does not seem to clutch slip. Once the gear has switched, if you punch the gas, the car takes off with immediate action. I was wondering if anyone else has experienced this. In case you are wondering, my car has only 9.5K miles and has never been launched or abused in a manner that I could say would have worn out the clutches. Apart from learning new things about this tranny and its different ways of handling certain scenarios, I love every bit of it. Its lightning quick upshifts and wonderfully executed downshift blips are without any parallel. It is truly the best of both worlds, i.e. crawling traffic jam world, and track use world, and satisfies my needs as a daily driver. Thanks for your input.
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10-07-2011, 05:25 PM	#2
llis octane chick 79 Rep 1,187 Posts Drives: ex-M Join Date: Oct 2010 Location: Colorado iTrader: (1) Garage List 2013 BMW M3 ZCP [10.00] 2003 BMW M5 [0.00]	I think it depends on your driving at the moment, in part. The double clutch system works fast by having the next gear ready to engage, but if you downshift when the DCT is expecting upshift, or upshift when the system is expecting downshift, you get a delay, more like a regular automatic transmission might. At least that's what it seems like to me. But all that's about slight delay. I can't say I've felt actual slippage, like a clutch going out.
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