redlightrich

Hello all, the first time I drove my GT3 ( I still lament its sale) I noticed that the trans acted like a automated manual. At idle it was disconnected from the motor, and it was waiting for throttle input to engage.

The TTs is programmed like an automatic, where it is engaged at idle, and will "creep" forward if conditions are right.
The gear ratios are also different in the GT3.

I realize these are very different cars in options and intended use.

I wonder if the TCU could be reflashed to GT3 type characteristics? Has anyone pondered this? My thought is there would be an issue with dissimilar software and hardware. Even if the TCU were swapped out, the powertrain modules would probably see some fault.

Has anyone explored this? Has anyone, who drove both cars have any opinion on this?

Yes, I am aware that the TTS and GT3 are very different, and designed to be.

I just was wondering what others thought about this.

Kind regards

Rich

GrandLaker

My TTS does not creep forward when in gear. You have to apply throttle to get it to move. Definitely acts more like a manual in that respect.

worf928

Interesting. Here's a question to ponder, or not: does auto-start/stop (AS/S) activation have an effect on this in 991 TT(S)s?

AS/S when activated also activates coasting mode. I could imagine that in coasting mode PDK might want throttle off-idle signal before engaging a clutch since when rolling the clutch(es) are disengaged when the throttle is in idle position.

My PDK creeps with no throttle when in gear, by my AS/S is always off. I will try to remeber to test this today.

EDIT: wait, that might be a 50% stupid question. If AS/S is on and you are stopped and the engine is off, you must give it throttle before it knows to turn the engine back on. The better question is if when AS/S doesn't cut the engine does it creap or not when in gear?

I'm not going to keep AS/S on for the length of time likely needed for "science."

Visceral

I *think* the AS/S only stops the engine when your foot is on the brake, and knows to start the car when you lift the brake so that its running by the time your foot gets to the throttle.

I have a few cars with AS/S, and I think this is how they all work.

speed21

You are right with that. The AS/S will only shut down the engine at a dead stop position with adequate foot pressure on the brake pedal. The moment you release the brake pressure, the engine fires back into life. It is the same with every Porsche I have driven with this feature.

OP the GT3 has entirely different PDK shift programming than the TT/S. It is more abrupt in the way it generally operates that the TT/S I found. With the TTS, the moment you lift your foot from the brake on a level surface it naturally engages a progressive take up of the clutches. On a hill you get the auto hill hold function that stops it from sliding backward...

worf928

No need to "*think*." You may assert, as you are 100% correct. I don't know WHAT I was thinking when I pontificated earlier today on this subject. That's the only way it really can work for various reasons. I realized my blunder as soon as I read your message.

Afterwards, I went ahead and tried AS/S. Until tonight, I have never activated AS/S. It was off upon delivery in Zuffenhausen and it has stayed off. (We, in the US, can be thankful that it doesn't re-activate after a power cycle. In Europe (and presumably other locales) its mandated to be activated at each start.)

Long story short: AS/S activation has no effect on whether my TT creeps from stop when in gear. It always creeps.

So, we have no explanation for why GrandLaker's TTS doesn't creep.

In my case, I almost always go paddle-neutral at a stop. Obviously, in that state it won't creep with or without brake pressure since it isn't in gear.

ipse dixit

You are correct.

Not possible.

Enjoy your PDK. There are many times when I'm stuck in traffic where I wish my PDK-S acted more like the PDK.

Tapeworm

Yeah, the PDK-S in the GT3 has some issues:

It only has 'normal' - which is pretty much the same as 'normal' in a regular PDK (i.e.: it sucks and will be in 7th gear by 40mph on light throttle). And 'sport' which is almost like sport plus on a regular PDK - it holds gears a long time and revs high. It won't hold each gear at light throttle until red line like a regular PDK, but it's still a bit too aggressive for regular driving.

What the PDS-S is missing is a 'sport' mode, where the revs stay above 2,000 all the time, but it doesn't hold gears until redline like a PDK. This means I drive it using the paddles a lot more, which is no bad thing (although the springs are heavier), but I do miss having normal, sports and sports plus modes....

I do like NOT having a kick down switch on the accelerator, which was more annoying than useful. I don't care the gear leaver is reversed, as I never change gear with the gear lever...

Not having creep is kinda cool at stop lights, just being able to take your foot off the brake, but you have to 'brush' 1,500 rpm to get moving, which just is annoying in stop and go traffic.

I do like the 'paddle neutral' feature - WHILE you hole both paddles, the gearbox goes to neutral - this is fun and let's you rev the engine while driving along, or 'drop the clutch' and spin the wheels - childish maybe, but fun.

I actually would be fine with a regular PDK in a GT3 (but then, I would like back seats too...)

redlightrich

Thanks for the replies, although it went all over the place. I want my PDK to act like a PDKs, so when my GT3 shows up in December, I will drive that and be happy once again.

Visceral

No worries. I wasn't quite willing to open the gates and go for a drive in the rain, so I had to preface my statement with a little bit of uncertainty.

Admitting my uncertainty on the internet hasn't ever harmed me IRL, and you'll probably agree that fewer people should act as definitive as they do here (present company excluded ).

GrandLaker

My AS is always off.

wrs

It even has a green lighted visual in the speedo that says hold. You can definitely see the clutch engaging gradually on gearshifts if you log data using the AP. That tool logs at 45hz so when running a quarter I can definitely see how the clutch is engaged "gradually" so that there is no slip.

FBA

My PDK will roll at idle if I don't hold the brakes...like most other auto trans vehicles.

speed21

Same. On a dead flat surface the take up is very subtle, very little forward movement, nothing that will get away from you like some autos will if you take your foot off.

FBA

I have more than subtle forward movement...like most other auto's.