CarManDSL

Do the different tunes of Normal, Sport and Sport Plus not satisfy power, engine response, etc., already?

Does the Viezu tune have different maps for each mode?

DBYT

Good question. I will let the Viezu and Fabspeed guys answer that. From my experience of the car, I usually only drive it in sport plus and noticed that the throttle responsiveness and low to mid range power was much improved.

chuck911

You should carefully read what DBYT posted above, especially the part "Why don't manufacturers tune their vehicles?"

In fact, manufacturers DO tune - they tune for a very broad range of uses and purposes. Even those buttons Sport and Sport Plus, they are merely a little less generalized than Normal mode. Porsche has on their website some very simple charts showing the way throttle mapping differs with mode. These charts are helpful, but they are gross simplifications! Also, they show only the relationship between the accelerator (gas pedal) position and the resulting throttle opening. Find the chart and you'll see a curve that starts off slow then increases. In the real world this is like telling the engine to take it easy the first few degrees you move the accelerator, but if you keep pressing down that you must be serious so start opening the throttle faster. And people wonder why there's low end throttle lag- its right there on the graph. It saves gas and saves a few inattentive or spastic drivers from rear-ending the guy in front of them every time the light goes green. Its a feature not a bug!

To lots of end-users though it will always be a bug. In my experience, you just can't get that real sports car feeling without really razor sharp throttle response. When I drive a 911 in Normal it feels like a Camry. Even in Sport mode its a little slow for me. But at the same time I have to admit that maintaining precise control over all that horsepower while caught in stop-and-go traffic is a lot more stress than anyone needs. So I understand the need for compromise. But now these Viezu tuners come along and, well just look at what DBYT is saying. "The car feels a lot more sporty." Just what the doctor ordered!

cmb13

Chuck - that's an interesting point. Maybe that's why the 3.4 feels a little sluggish, not like a 4.6 0-60 car. Maybe it's because of a gradient in the throttle response?

I'd also love to change sport to the default mode.

chuck911

I have absolutely no doubt that one of the factors Porsche tunes for is marketing, specifically, to be sure there is enough subjective performance difference between models. I know some will question this, but it is just so obvious. I mean, even Porsche acknowledges they programmed the GT3 steering, throttle and shifting to provide the experience track drivers demand. Sure some of this, especially PDK shifting speed, requires new parts and cannot be achieved with programming alone. But an awful lot is pure programming. With steering feel and throttle response, I bet around 90% of the difference is programming. I'm talking perception here. Of course no amount of programming is going to replicate the feel of high spring rates or that monster motor. But just look at the difference between Normal, Sport, and Sport Plus. Just how hard could it possibly be to provide another button, Track, or even a fourth? But then a lot of potential buyers would start to question the value in stepping up to a GT3. Same goes across the model ranges. Ever see the video where the Cayman is just a tiny bit slower than the 991, even on a course the testers thought would favor the Cayman? You don't think Porsche already thought of that? Or that they'd allow a 991 to feel snappier than a 991S, when they know they can dial in whatever performance sensation they want just with a simple throttle mapping tweak? These guys are way, way more sophisticated than most of us give them credit for.

fxz

Where s the Dyno charts?

What about changing the PDK pinion
to make all the gears shorter and then the engine more responsivness?

It would cost 500$ only

MerlinsGarage

This is fact. We found this out a few years ago with a GM vehicle, the Pontiac (Holden) GTO.

At 400hp the car should have shredded the tires on standing start WOT. Not so.
The pro tuner we called explained for warranty and driveline longevity purposes GM specifically dials back throttle response for launch and higher torque scenarios.
After the tuner did his magic it turned the car into Mr. Hyde.........unbelievably totally different car.
I would believe all manufacturers do the same thing, Porsche would not be an exception.
My question would be if PCNA would be able to detect a software change (time stamp) and if so would it void the warranty?
Additionally are the NA cars mapped differently than the rest of the world?
Rhetorical questions for sure since the mapping and mappers are proprietary and non-disclosure respectively.

..............but boy would I like to try it!!

DBYT

Haven't made the time to head back to Fabspeed to get the dyno done. Will post when I do.

O5C4R

Very interested in this tune and possible GT3 steering tune, looking forward to the results, thanks

tradervic

Avail in US?

chuck911

This is exactly what I was getting at. No engine as beautifully tuned as a 991 with DFI should ever be generating comments about slow throttle or lag anywhere, any time. Instead the complaints should be about the challenge of learning fine throttle control to avoid excessive wheel spin. If there is a lag then believe me, it was deliberately tuned in to meet what Porsche considers larger design goals- economy, longevity, reliability, drivability, whatever.

Tune these back out and you will indeed have a totally different car.

MerlinsGarage

Run a freekin' cable from the gas pedal to the throttle bodies.

But seriously, it would be nice to use one of the blanks on the console for, "Viezu Tune".

MerlinsGarage

This is interesting. Let us know when you hit the dyno.

Thanks,

Bret.

Bacura

.........I'm just amazed that people drive their cars in sport plus all the time. Buying a Veyron as a DD would probably provide enough power.

robbonds

Sport plus in manual ALL THE TIME. Never sport plus in auto unless I wanna play around with launch control which I've done less than 10 times in 3.5 yrs