PDK Observations
04-03-2015, 11:54 PM
#46
Nordschleife Master
Nothing at all, IMO.
That said, I think the jerkiness that some people object to isn't so much in the 2nd to 1st downshift that you describe, but rather when the clutch finally and automatically disengages from 1st as you come to a stop. By pulling the paddles, you can disengage the clutch earlier and coast to a smoother stop without that final "clunk". Sometimes I pull the paddles and sometimes I don't. Nothing wrong with either method.
That said, I think the jerkiness that some people object to isn't so much in the 2nd to 1st downshift that you describe, but rather when the clutch finally and automatically disengages from 1st as you come to a stop. By pulling the paddles, you can disengage the clutch earlier and coast to a smoother stop without that final "clunk". Sometimes I pull the paddles and sometimes I don't. Nothing wrong with either method.
Seems like a lot of little tricks to discover as you're learning the car. I guess practice makes perfect.
04-04-2015, 12:07 AM
#47
Race Director
i have alwasy found this 2nd to 1st shift when slowing to a stop to be clunky. with my cls63, my f10 m5, my e60 m5 and now even with the gt3... and they all have different transmissions, (except for the f10 and gt3 - both DCT's)
have always wondered what it was caused by...
have always wondered what it was caused by...
It takes a fairly skilled driver with a MT and clutch to make a really smooth 2nd to 1st shift. It must be difficult to program the automatic clutch engage-disengage function in a DCT to rip off millisecond shifts at speed and yet also slip the clutch enough at very low speeds to make that 2 to 1 downshift and then stop a smooth one.
04-04-2015, 02:49 AM
#49
Racer
Join Date: Feb 2014
Location: edmonton, alberta, canada
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Yeah, I don't know for sure. But with most stops you don't roll in first gear very long. It's second, then first-declutch....the last two usually happen in pretty quick succession so maybe that's part of the problem.
It takes a fairly skilled driver with a MT and clutch to make a really smooth 2nd to 1st shift. It must be difficult to program the automatic clutch engage-disengage function in a DCT to rip off millisecond shifts at speed and yet also slip the clutch enough at very low speeds to make that 2 to 1 downshift and then stop a smooth one.
It takes a fairly skilled driver with a MT and clutch to make a really smooth 2nd to 1st shift. It must be difficult to program the automatic clutch engage-disengage function in a DCT to rip off millisecond shifts at speed and yet also slip the clutch enough at very low speeds to make that 2 to 1 downshift and then stop a smooth one.
but thats no fun.. lol .i like shifting to first when im still doing, you know 30-40...
04-04-2015, 02:53 AM
#50
Yeah, I don't know for sure. But with most stops you don't roll in first gear very long. It's second, then first-declutch....the last two usually happen in pretty quick succession so maybe that's part of the problem.
It takes a fairly skilled driver with a MT and clutch to make a really smooth 2nd to 1st shift. It must be difficult to program the automatic clutch engage-disengage function in a DCT to rip off millisecond shifts at speed and yet also slip the clutch enough at very low speeds to make that 2 to 1 downshift and then stop a smooth one.
It takes a fairly skilled driver with a MT and clutch to make a really smooth 2nd to 1st shift. It must be difficult to program the automatic clutch engage-disengage function in a DCT to rip off millisecond shifts at speed and yet also slip the clutch enough at very low speeds to make that 2 to 1 downshift and then stop a smooth one.
04-04-2015, 09:49 AM
#51
Nordschleife Master
I don't know guys. I guess I just lucked out with my car. I put it in auto and forget it. Up shifts and down shifts are seemless in auto. Now if I use manual and down shift above 2000 RPM the downshift 2 to 1 can be rough - slight lurch as gear is engaged not matching speed of the car. But no clunk...
04-04-2015, 01:58 PM
#52
Race Director
I don't know guys. I guess I just lucked out with my car. I put it in auto and forget it. Up shifts and down shifts are seemless in auto. Now if I use manual and down shift above 2000 RPM the downshift 2 to 1 can be rough - slight lurch as gear is engaged not matching speed of the car. But no clunk...
04-04-2015, 02:08 PM
#53
Three Wheelin'
So if I am in manual mode and approach a red light in second gear and simply stop, the car shifts from second to first on its own to not stall. This is a smoother shift than if I did it myself yet no paddles are pulled. What is happening in this lazy scenario? Is there anything wrong with it?
This is what I do. Best solution IMO
04-04-2015, 02:10 PM
#54
Three Wheelin'
yes, and in similar situation when in auto and pdk sport i think the transmission will already be in 4th. the problem is i dont think 4th is low enough (for max acceleration) because when im in pdk sport and auto, as we know ist always in the lowest gear so when you floor it your not in low enough gear so it bogs a bit. it should go to 3rd, or even 2nd, as there seems to be lots of revs left on the tach... im pretty sure on this, so it seems they tuned pdk s to be more for track where theres always turns coming, than flat out speed? either way i wish it kicked down at least 1 more gear when in pdk sport.