DCT, gear change speed, and throttle blips

[andywaterfall]

Quick question for the PH experts please:

I generally keep my DCT in M2 (ie starts in 1st, smooth changes up & down); I'd like the throttle blips you get on downchanges in S5, but the jerky upchanges put me off. However, occasionally I get a downshift blip even in S2 when going from 4th to 3rd, but it seems random. I can't for the life of me replicate it - I've tried all combinations of throttle on/off, brakes on/off, high/low revs, but can't make it happen.

So - anyone know the parameters that create a throttle blip?

[MrOnTheRopes]

From my brief experiments with the lower settings I'm not sure about getting the downshift blips.

Don't like the sound of "jerky" changes though. My DCT certainly isn't jerky (ie only use S5 and S6), just a sporty little kick in the back under full throttle.

[andywaterfall]

Hmmm - S5 upchanges are fine when tootling about, but when I'm going for it, I find full-bore upchanges really jerky - they unsettle the car quite badly. I don't think it's just my car, but maybe I need to try another to be sure.

[dele]

andywaterfall said:

Hmmm - S5 upchanges are fine when tootling about, but when I'm going for it, I find full-bore upchanges really jerky - they unsettle the car quite badly. I don't think it's just my car, but maybe I need to try another to be sure.

I think it is just your car mate, mines fine on full bore upshifts?

[Gokartmozart]

Mine has a distinct "lurch" in S5 too. (58 Plate).

[andywaterfall]

Maybe I'm not going mad then

Seriously, you chaps who haven't got it - if you change up 3rd-4th in S5 at full throttle at say 7000rpm, it just slurs nicely from one gear to the next, with no lurch, or jolt? I don't use S5 now, after a big sideways moment a while back, while making that kind of change on a very gentle curve.

The ideal for me would be S2 upshifts & S5 downshifts. I wonder if someone clever could write some software to do that...

[Mr Bimmer]

When did you last have your DCT firmware updated? It's been much better since March 2010

[MrOnTheRopes]

andywaterfall said:

Maybe I'm not going mad then

Seriously, you chaps who haven't got it - if you change up 3rd-4th in S5 at full throttle at say 7000rpm, it just slurs nicely from one gear to the next, with no lurch, or jolt? I don't use S5 now, after a big sideways moment a while back, while making that kind of change on a very gentle curve.

I get a nice thud in the back but I wouldn't say it was a "jerk" - like in your opening post. It's smooth in that the passengers don't flop around like rag-dolls like they would with an SMGII S5 change

And yes it can light up the back wheels and go sideways but hey, that's the fun innit

[MrOnTheRopes]

PS Mine's a Mar 2010 build (Alpine Edition)

[andywaterfall]

Don't get me wrong, I like going sideways as much as the next man, but only when I want to, not when the car decides to!

Anyway, it's booked in for tomorrow now to have a DCT software upgrade under warranty, so I'll let you know how it goes.

[andywaterfall]

Huh. Turns out I had the latest software already, so no change. They test drove it too and said it was working as expected, so perhaps I'm just being over-sensitive to unsmooth changes... Maybe I'll take a test drive in a new car, see if I'm being fobbed off.

Shame really - my idea of S2 upchanges (v smooth and quick enough), and S5 down changes (lovely blip & v quick) would be great!

[Defcon5]

So if its not matching the revs on down shifts on some modes, what is it doing? Slipping the clutch?

[dele]

Mines an 09, dont think its been updated so i might be on the older version of DCT software?

But im still adament mines smooth, even on max setting with the TCS off?

[andywaterfall]

Defcon5 said:

So if its not matching the revs on down shifts on some modes, what is it doing? Slipping the clutch?

I guess so - it's like when you change down manually without a blip - you let the clutch pedal out, the clutch slips a little, the revs rise, you're in the next gear down.

[dele]

andywaterfall said:

I guess so - it's like when you change down manually without a blip - you let the clutch pedal out, the clutch slips a little, the revs rise, you're in the next gear down.

Mines never done that?

You sure your clutch isnt knackered? Or even worse, gearbox?

[andywaterfall]

dele said:

Mines an 09, dont think its been updated so i might be on the older version of DCT software?

But im still adament mines smooth, even on max setting with the TCS off?

Mine definitely jolts during full bore upchanges from say 3rd to 4th, and it badly unsettles the car.

[andywaterfall]

dele said:

andywaterfall said:

I guess so - it's like when you change down manually without a blip - you let the clutch pedal out, the clutch slips a little, the revs rise, you're in the next gear down.

Mines never done that?

You sure your clutch isnt knackered? Or even worse, gearbox?

Sorry, I wasn't clear - I only meant the clutch must slip a little to go from one gear to the other, without a blip, to make the engine speed match the road speed. I'm sure my car's fine on slurry downshifts, it's speedy jerky upshifts I don't like.

[swanny71]

I to loved the blips but hated thumping upshifts in S5 so spent a while messing with settings etc.

Leave it in S5 (for blips on every down change) but use a small, well timed throttle lift to eliminate the jerk when changing up. This also eliminates the horrible 'automatic slur' sound on gear changes.