Dartmouth

Mine does the same thing exactly!

ADias

It's not adaptive learning. It is a system calibration to adjust the hydraulics for wear.

Adaptive learning comes afterwards as you drive it and the tranny relearns yours throttle application driving style and picks/adjusts shift maps.

Big Swole

Yes Sir. I guess I'm just not saying the proper term, even though that's what other tuners / folks keep calling it (what you described).

Yes, that's what I want to have done with the COBB if / when I buy some tuning.

Thank you.

colbyp7

Mine does the exact same thing. 2011 C2S. Did you do the PDK update? If so, what are your thoughts? I have it scheduled but getting cold feet!

colbyp7

Did you do the PDK update? If so, what are your thoughts? I am about to bring mine in but now 2nd guessing it!

gargamel647

I did not do it. I have a PDK service coming up and I may do it then.

thefunkygibbon

thread necromancy.....
anyone have any updates on this? I've just found this thread and i can totally relate to the hard judder going from 2>1 in Sport mode. , but also i am seeing the following issues
- Slow to go into Reverse/Drive when at standstill
- Randomly holds on to 1st for too long and have to manually change else end up waking everyone in the street up. More likely to happen after going back to normal mode after being in Sport mode.

myltz400

Funky,
Is your PDK an early model? As mentioned these are not the smoothest of the lineage.
The 2nd to 1st downshift in sport modes has a jerk/lunge to it on my 2009. It has become much better for reasons I can not explain, probably a combination of learning how to modulate the brake and some maintenance I have had performed.
The slow engagement of drive and reverse I have never experienced, could it be associated with temperature (ambient and internal fluid)?
Holding 1st gear sounds like a cold start process to me, I wish mine held 1st longer while in not in sport or sport+.

My issues were more like a sloppy differential sound that annoyed me. I addressed this with a dealership PDK fluid change. Like others have said, He advised against the software update and manual calibration stating that many times these go badly on the early models. I followed this advice!

The fluid change didn't seem to change much for me, but it needed to be done anyway. One thing I did have done that changed the noises I was annoyed with was a transaxle fluid change. The kind of sounds you hear when you let someone else drive you manual. The load/unload of the gearset. This procedure (for whatever reason) made the car much more quiet while driving at very slow speeds. I believe this is a big reason people are dissatisfied with auto gearboxes in sports cars, learning your way around your manual with a clutch is not always about speed shifting but about smoothness and the reward of getting to know the machine.

Maybe start with some maintenance if it has not been done to date?

thefunkygibbon

Hi, yes i guess it's 'early'? its a 2010 model.
Yeah the more i read about it now it seems the jerky 2>1 is just 'a thing' i'm going to have to get used to. I drove yesterday and tried to work out how to specifically replicate the issue, but i really can't seem to work it out. it seems to happen whether i'm braking or not. i tend to come to a natural stop most times anyway, braking probably already when it's gone down to 1st. are you saying i need to brake differently somehow? i really am not sure what that means. even if i did brake, i'm hardly going to be slamming my foot down on the brake (and in of itself causing its old jerk)

Its had its 6 year PDK clutch oil change but not yet the 12 year transmission oil change (is that what you are referring to the "transaxle fluid change"?) . I've looked through my paperwork and it looks as though the previous owner also tried to get the jerky 2>1 looked at under warranty 2-3 years ago, but it was NFF'd.

as for the other issues, I didn't get the slow reverse/drive change this time, so i think that is likely temp related... it was pretty freezing outside when i last had the issue.

the holding on to 1st gear isn't really a cold start thing. i usually get it when going from sports mode back to normal mode, and it seems that the PDK gets confused with the remapping. i always have to change up manually as it really is embarrassing driving along at 10mph down a street at 7000rpm.

myltz400

Sorry, I probably ranted a little bit too much in my previous post.
I don't think the gear oil change would address any of your issues. Some of what you speak of seems normal however I have never experienced the prolonged first gear situation. The advice I chose to follow for my 997 was to not do any updates or manual calibrations. However they might help in your situation.

ReelBigAndy

I believe if you are on the gas when you change drive modes (normal into sport, sport back to normal, etc.) the car waits until you release the gas pedal to actually change modes. Not sure how instantaneous your change and symptom are, but I'm pretty sure if you change into normal mode but stay on the gas, It will actually still be in sport until the gas is released. Just something to think about if you haven't already considered it.

Wayne Smith

I'm at the high end of my street. When I take off in the morning I back down the driveway before driving down the street. It is steep enough as I negotiate around the cul-de-sac and past potential wildlife that the car remains in first gear in engine braking mode. That gets the revs higher than I like with the motor cold. So I manually upshift. This puts the car in manual over ride for 8 seconds but gets me out of first gear.

I don't know if this is what is happening in your case or not. I do know that like any auto transmission shift points are a function of pedal position.

The difference in sport modes is the minimum rpm allowed before a downshift will occur. That means on a natural throttle off slow down it will drop to a very low geared first with high rpms performing engine braking. Short of undesirable clutch slippage I'm not sure what you're expecting other than a hard jerk. If in sports modes you should be braking to a stop, not coasting.

thefunkygibbon

Fair enough. It's going to OPC next week for something else, and i've asked them to take a look at it, no doubt it'll just be NFF'd though as usual.

Interest, next time i test it i'll ensure i take foot off completely between changing modes to see if it makes a difference :-) thanks

i understand the differences with the throttle response and pdk mappings between sports modes and normal. It's not coasting as it's still in gear, but it happens when braking too !
I'm not going to be putting my foot down hard on the brake. regardless, unless either on a track/driving spiritedly. which for the purposes of using plain old sport mode isn't an unreasonable thing to expect/do.

I appreciate that I do not know the intricate details of how PDK's work and how they are designed to work, but some things don't make sense, especially when it doesn't appear to be consistent, all things being as close to equal as possible, sometimes it jolts, sometimes it doesn't. Doing the exact same gear changes 'manually' (changing gears at the same points/rev ranges) does NOT cause the jolts like it does in auto.