bweSteve

Hey guys, I don't think I've seen a recent discussion on this subject specifically...

I was out bombing around in my gen2 / 3 yesterday, and as always, I find myself at a location, and mood, where I decide I want to get the car sidewayz & play around with the oversteer. I love it. Its so exciting,... and since my wife & I came from the world of our RWD 964 Turbo, and both have similar fun in that car for 20 yrs, it was a natural progression for us in the GT3 (although I will say that it takes some getting used to, when the car corrects us when we leave those nannies on)

Anyway,... in that situation, I typically press the button to turn off BOTH SC+TC, because all I really want to do is get it sideways & power out. During those times, I don't see any use to press SC, and only turn off the Stability Control.

I've always thought it would have nice if Porsche gave us a SC+TC button to turn both off,.... AND gave us a single button to only turn off TC. BUT, I also know that the engineers & Porsche drivers know a LOT more than I do,.. and there has GOT to be a good reason for how they gave us the car. So I do not question that part. .... so I press the SC+TC button & go on my way.

So,..... how many of you ever press ONLY the SC button, and can you please tell me the situation in which you want only SC off.

Any other thoughts are also welcome.
=Steve

RAudi Driver

Not having any idea what you were talking about I looked at the .2 interior buttons and see that you have a few more buttons than the .1's. So it was rabbit hole time while drinking my morning cap. On my Audi RS4, there is one button. A quick press deactivates traction control allowing the cars tires to spin and have some fun. A long press deactivates both traction control and stability control. To me this sounds normal.

I see on the .2, you have 2 buttons, one being the SC and the other being SC+TC. I can't think of a situation where one would want to deactivate just the stability control of the car. I would think if one wants to play around and drift, you would either deactivate both nannies or just put the car into sport mode and get rid of the traction control. Can you not just deactivate the traction control?

Whatever the case is, this is a nice topic for discussion.

Good morning everyone!

Bxstr

Just to add, 996 GT3 did not have traction or stability control. 997.1 GT3 had traction control. 997.2 GT3 had traction and stability control.

Elliotw44

Steve in the owner's manual it speaks to the difference of SC off vs TC + SC off. SC off actually puts the TC in different mode which allows more wheel slip. But I agree with you for sideways fun it's TC + SC off.

FLT6SPD

These SC and TC buttons equal PSM (Porsche Stability Management)
This is also why the DSC module is plug and play on the .2 (TC+SC) and have to add a gyro to the .1 cars (TC only)

TC off = fun, TC + SC off = your on your own

PSM -Porsche Stability Management

PSM is an automatic control system for providing stability at the limits of dynamic driving performance, and is a standard feature of every 911. Sensors work continuously to monitor the driving direction, speed, yaw velocity and lateral acceleration of the car. Using this information, PSM computes the actual direction of motion. If this direction deviates from the desired course, PSM initiates braking interventions targeted at individual wheels – recognisable by the flashing indicator light in the ****pit – in order to stabilise the vehicle.

Under acceleration on wet or low-grip road surfaces, PSM improves traction using the ABD (automatic brake differential) and ASR (anti-slip regulation) functions. The control interventions are smooth and precise, giving an agile response. When ‘Sport’ mode is selected on the optional Sport Chrono Package Plus, the PSM intervention threshold is raised to enable greater driver involvement – particularly at speeds of up to approximately 70 km/h (45 mph).
The integrated ABS shortens the braking distance even further and the braking inputs are smooth and precise, thereby enhancing comfort.
An enhanced PSM system, now also available in rear-drive models, is characterised by two additional functions: the precharging of the brake system, and brake assist.

If the driver suddenly releases the accelerator pedal, the PSM automatically readies the braking system. With the braking system having been precharged, the brake pads are already in light contact with the brake discs. Maximum braking power is therefore achieved much sooner.

When sudden braking is detected – i.e. if the pressure on the brake pedal exceeds a predefined level – the brake assist function uses the PSM hydraulics to apply maximum brake pressure to all four wheels.

If you want a purely active driving experience, you always have the option to deactivate PSM. It is automatically reactivated, for your safety, only if either of the front wheels (in sport mode, both of the front wheels) requires ABS assistance. The ABD function, however, remains active at all times.

JB911

Once in a while I turn both off, but haven't tried purposely peeling out-
I have noticed that since changing from Cup2 tires to the 4Ss, I have more brake dust from spirited drives-

JB

powdrhound

I believe the above description applies to the regular 911 and Turbo. On the 7.2GT3, PSM when turned off via the TC+SC buttons will NOT turn itself back on under braking as per the last sentence above. 7.2GT3 will stay free of all nannies including ABD until you turn them beck on via the button. Essentially with TC+SC OFF, the car is a 6GT3 with ABS only.

bweSteve

Thanks everyone for their posts & input above. I have read, and re-read the posts, as well as my owners manual several times since starting this thread.

... I am "close". I am close to thinking that I have all the information burned into my memory banks,... so this Spring/Summer, when I'm out bombing around, and come upon a situation where I would like the car to be a little more free,... I have it in my head how it will react to my inputs. I want it to be second nature. so far, for these last 3 yrs of ownership, I've really only pushed the "Sport" button, and then quickly added a push to the "SC+TC Off" button, when I knew I could play around a little bit (safely). I have been conservative with my inputs though,... mostly because the car has been new to me, and I don't want to make a bigger mistake I can't take back. But I must say, this car inspires confidence. I have yet to experience a moment where the car did not act just as I suspected. But now, armed with more knowledge in the back of my head, I feel I will soon even better understand what it was designed for.

I will revisit this thread again this Spring/Summer!!!

point2point

I played around with the different settings earlier this month at Buttonwillow during a day of continual rain. I had the track completely to myself for several hours and got to hoon around a bit, exploring the GT3’s behavior at the limit of grip. With SC and TC both turned on it was still possible to get the car sideways with a sharp jab of throttle coming out of turn 2 (cw13), but all I had to do to straighten out was to lift off the throttle. Repeating the same turn 2 power oversteer situation with SC off and TC on required opposite lock to catch the slide, but I didn’t have to be too delicate with the throttle thereafter. With everything off, it was possible to get into a tankslapper even if the correct amount of lock was used to catch the first slide. What caused this was clumsiness coming off throttle too abruptly followed by reapplying too much throttle.

I spent most of the day with everything turned off so I could practice quick yet measured inputs. If I just wanted to be fast on a wet track, I would turn off SC and keep TC on.

8Lug

Powderhound is correct. That description only applies to non-GT models equipped with Sport Chrono. In the GT3, the sport button has no effect on suspension or PSM settings.
To Steve's original question, just using SC off gives the car freedom to let the *** end hang out in corners. It makes the car feel much more lively when driving through curves aggressively and for me, eliminates all instances of any nannys coming on. Turning off SC+TC would essentially allow you to also do burnouts. Whether they be from a standing start or once you induce some oversteer in a corner (think Chris Harris videos). I've never found use for this feature and don't see it's benefit in street driving, and I don't abuse my car by performing gratuitous burnouts. Maybe on a track, turning off TC would be a benefit, but I've never tracked this car.

bweSteve

excellent recap P2P. Thank you for describing those situations, and for SURE that sounds like a great day of exploring the cars limits (safely).

8Lug,... thank you as well. I agree with most all of your opinions (on when to use, when not to use), except for the spinning of tires part (I am purposely not using the word "burnout", since that connotates a completely different type of driving for me. I own several late 60's GM muscle cars, and yes I do water-box burnouts at my local drag strip all the time. even do a few burnouts on the private {long} dead end street at my house).

But with a GT3, .... here's a good example:.... I sometimes find it quite satisfying to be stopped at a intersection of 2 roads (most always out in the country roads), plenty of visibility, & decide whether there is enough asphalt, no guard rails on the exit, and plenty of runoff if I happen to get into it too aggressively,... push a button (or two) on the console, and away I go with a nice aggressive turn (yes the tires are spinning at this point), applying the correct amount of throttle to keep the tires spinning until I straighten the car out, and nearing the completion of the exit I ensure I don't chop the throttle (prevent an abrupt grabbing of the tires especially if you are not yet pointed in the correct direction!).
... anyway, that's just one instance where I have not yet tried it with ONLY the "SC Off" button pushed. I will probably try that this Spring/summer, and hopefully I achieve a similar result to P2P's description above.

In the end, there is so much talk on RL about valuations on these GT cars,... and I try very hard to keep my mind in the same place that I have been for 20+ years of driving our 964 Turbo spiritedly. It is the spice of my life, and I will be dammed if I am laying in a hospital bed decades from now, and wish I drove my cars harder.
Knock on wood, I have only ever had one minor fender bender (~ 30 yrs ago) from getting a car sideways on purpose, and it was a newly acquired 69 Camaro that did not have a posi rear differential. Up until that point, all my cars had posi,... so I was surprised at how poor the car performed when spinning only one of the rear tires. I ended up off the road (the same starting slide I described above, so I was probably only going about 10mph) & slowly came to a stop up against a guard rail (easy fix & paint on the front fender).

The bigger / higher risk slides are those where you're already moving through a turn at speed, and take it to the Chris Harris level. I still only hit those situations seldomly, since most of my driving is on the street, and those tend to be a stretch from my comfort zone.

Oh,... the other thing I think I have derived from my readings, is that for the GEN 2 cars that have stock exhaust valve actuator setup (ie the 3k or 4k opening of valves depending on whether you have the Sport button pushed or not), Porsche does initiate a slight ignition timing change to be in line with the more open flowing exhaust. THEREFORE,... since I am running a center muffler bypass (SW) AND the Carnewal system which allows me to run with valves open 100% of the time if I so choose,.... I think it might be wise to run with the Sport button ON, ALL the time.

The only question I have in regards to that ^^, is whether Porsche has some intelligence built into that ignition timing change, such that it only happens above the 3k rpm level ?,... or, when the Sport button is pushed, is that ignition timing change effective 100% of the rpm range? .... seems to me that it the ignition timing would be set for 100% of the rpm range WHEN the sport button is pushed (not just for when the engine is above 3k .... which I do not think our cars are "that" smart).

anyway,... winter time ponderings

cds4402

Since the exhaust valve is only open from idle to 8mph, and then past 3/3.5k, I would assume the timing change would only occur after the exhaust opens back up. But I’m just guessing.

powdrhound

You can simply datalog the car with and without the sport button ON and compare the logs. Ignition timing is one of the parameters. No more guesswork....

CRex

997 was the last street car where I had tens of hours of seat time on track playing with TC and SC and the Sports button.

You want easy power oversteer? TC off.

You want big liftoff oversteer? TC+SC off. Emphasis being “big”. Our car rotates on weight transfer as is—variable being when the brakes come in under SC to arrest that rotation.

Call a rose by any name, PASM PDCC PIDKW, the fundamental variables are throttle, braking and suspension stiffness. TC is throttle. SC is (mostly) braking. 997 chassis control is still primitive to be talking about effect of dynamic damping on rotational characteristics.

Sports mode changes throttle response and ignition timing. But to talk about power train characteristics under 3krpm we’re simply not driving this car right.

From 997 onwards that TC and SC have evolved from DOS 6.0 to the MacOS X… I am still scratching at the surface of the 991.2 systems…

bweSteve

[QUOTE=CRex;17884503] .... You want easy power oversteer? TC off. ...
....
/QUOTE]

How do you ONLY turn off TC in your .2 ? ... I ask only because in your next statement you talk of turning off both SC+TC.