LavaGTS

I installed the Accessport with PDK flashing on a 991.1 C4S. The Stage 1, 91 octane tune is fine. Didn't notice any gains with an otherwise stock vehicle, although I'm sure something is there. It will definitely wake up with some mods+pro tune.

The PDK flashing on the other hand was a waste of money. More suited towards vehicles without SC

-"No Creep" does not operate like the "HOLD" feature the 991.2 has. It feels as if the vehicle is neutral and you are wearing out the clutches when trying to inch forward/back. The vehicle will roll back and forth, the 991.2 will not do this.

-Sequential shifting.. Cool, no big deal.

-Normal mode turns into sport mode, and sport mode almost turns into sport plus. It doesn't really shift any faster, just harder. It feels like you're wearing out the tranny when trying to have a spirited drive in sport mode. It holds the gears far too long in normal mode and a tad long in sport mode. There's no way to get the car to be tamed in "D" when you're just trying to cruise. The PDK loses its famous characteristics where it knows exactly what you want to do. You must drive in manual mode when you want the car to calm the F down. This is really annoying at times.

-No kick down is the best feature it offers although this can be avoided by not fully pushing down on the accelerator to the point where you hit the button.

IMO PDK flashing should be included for free as we are already paying double/triple the price compared to other platforms.

phx991

Not surprising given that Porsche spends north of 2.5 billion a year on R&D.

991carreradriver

Can't speak to the PDK tune, but I was extremely pleased with the 93 octane tune on my C2. There was a very noticeable difference. These cars are de-tuned to meet emission spec's. There is a lot more in the NA than comes out of the box from the factory.

Gus_Smedstad

Will a tuned car have trouble passing emissions tests? Some 33 states require annual smog tests.

Noah Fect

A PDK tune makes sense only if it comes with a graphical editor that lets the user create their own shift maps based on RPM, throttle position (and at least its first time derivative), engine load, forward and lateral acceleration, and probably some other parameters I'd only realize I wanted if I were actually playing with it.

My understanding is it doesn't, so... I'll pass.

pfbz

Nino, i guess you went ahead with the Carmax C4S purchase? Enjoying it? Did CarMax / Porsche work out the overheating issue for you?

My thought was that the Cobb PDK tune made non-Sport-Chrono PDK cars potentially worth considering. 991.1 gen PDK without sport+ mode, for me, is a fail. And that perhaps the new Cobb PDK tuning could move a used car without SC from being excluded to a possibility for purchase. It will be interesting to see if any of the top Cobb custom tuners will do any more with the PDK maps.

Johnny5Alive

I only drive in auto mode when I'm on the phone or cruising on a road trip.

Just drive in manual. Boom. DIY PDK flash.

991carreradriver

I remember reading a recent post where that was the case in CA, I believe.

LavaGTS

Yes I went ahead with the purchase, they never addressed the issue but it has yet to surface again. I am still in the market for a variety of different 911's. If I find one I will be giving the C4S to my brother. This one has been good, just a couple of small quirks( window switch rattling under bass, another rattle in 7th gear under moderate acceleration). Put on some gorgeous Carrera Classic widebody wheels.

I would agree with you that the PDK flashing is better suited towards 991s without SC

COBB Tuning

Hey Nino, we definitely appreciate your feedback and are bummed to hear you don't feel the PDK tuning was worth it for you.

We are obviously still relatively new to transmission tuning and expected to see feedback that would help us to hone in on features and calibration style with future PDK Off The Shelf Maps. Features that work on Turbo cars may not be as beneficial to naturally aspirated, and so on. Just to clarify, are you saying that using the COBB Sport PDK OTS Map in Normal mode seems too aggressive for daily driving or is all of your feedback based off of the COBB Sequential Style OTS Map?

Marshall@COBB

neil.schneider

I had a tune done on my last 911. What a waste of money. I think it was a Cobb tune as well. Never again on a N.A. car. I had no performance gains and got an ignition knock to boot. Set it back to the factory.

pfbz

Cobb makes tuners, they come with some included tunes, but often independent tuners load their own tunes on it for customers.

Sorry if your not happy with your tune, but I'd make sure you knew who tuned your car and if it was a 'canned' Cobb tune before disparaging a company with a pretty good reputation...

LavaGTS

After still driving the car with the Sequential style map this whole time I can probably give a little more helpful feedback.

Driving in normal mode is OK. Driving in SPORT in "D" is what gets extremely frustrating. The car is a lot more lively, there is a definite increase in power vs normal mode (which I like) but it just holds the gear way too long no matter what the throttle position is. The beauty in the stock PDK is that the tranny was programmed to know exactly what do to and how to behave depending on throttle position. The PDK flash has ruined that now. Normal mode is bearable but it still suffers from holding gears too long even when there is minimal throttle. It will hold the gear until no matter how little throttle is applied.

Excuse my posts if they are unclear or poorly written. I am usually in a rut and don't have time to proofread so I just type away.

simplex

I am extremely happy with the Cobb Sequential PDK and 91-octane engine maps. Transformed my 991.1 - it's like I have a new car now.
Best $2K I spent.

I was considering selling the car due to the frustrating factory PDK algorithm, which short-shifted even in Sport mode. I don't always drive in Manual mode, so that was crucial to me.

Not any more. The Cobb Sequential map has given me a car which is tremendously satisfying to drive. Plus in Manual mode I now have the correct stalk shifting pattern (push to downshift, pull to upshift).

Thank you Cobb! If you're reading this, please don't change the map just because of some unhappy customers.

Justadoc

First time ever post.

FWIW

Disclosure: I have a 981 Boxster S no Sport Chrono, Cobb Accessport engine and PDK tune. I know this is a 991 thread, but felt it was most applicable.


Agree mostly with Nino. The Cobb PDK tune (any variant; Sport, Aggressive, Sequential) takes away some of the brilliant factory "intuition/intelligence" the PDK inherently possesses. From the factory, the PDK reads your mind. With the Cobb PDK tune, it seems a little "programmed" i.e. it is waiting to hit cutoffs and data points to make shifts.

The shifts are definitely more aggressive with Cobb. Head snapping. The car does PULL more aggressively (due to the decreased clutch slip?) at the top end of the tach and I "feel" the car is faster. And I like this a lot. My 0-60 is 3.9. Consistently. Pre Cobb was 4.6 at best. However it is less refined to drive on the street as a result.

On the track I do enjoy the stronger pull again, but the "programmed" nature of it takes some of the "ballet like" bliss away from this brilliant vehicle.


My ideal Cobb PDK tune:

Normal Mode: increased shift times, same clutch pressure, stock "intelligent" shift points

Sport: increased shift times, increased clutch pressure, decreased continuous clutch slip, "intelligent" shift points (that coordinate with throttle position), no kick down


+/- reverse shift stalk

+/- paddle neutral

+/- idle creep disable

+/- race start (cool for 0-60 time measure - thats it)


Also, slightly concerned long term with the increased redline coming in to play with over rev counts.