Exact Effect of Sport Chrono

From what I read so far, the effect of the Sport Chrono on the Cayman and Cayman S is: 1) Remap the throttle circuit only to shift the entire map earlier in the throttle travel 2) Turn on PASM sport mode 3) If tiptronic exists, shift to a more aggressive map. NOW, for the other 911 997 Porsches (except the GT3 and Turbo), there is another effect: 4) Remap engine management to produce better response and shift cam timing to a more aggressive map, while HP remains the same And for the GT3 and Turbo 997, there is YET another effect: 5) Increase HP and Torque using engine remap and cam map shift. Can anybody confirm this for me? Any comments? I am getting a Cayman and I am not ordering the Sport Chrono option simply because my feet can press the throttle harder and I am having a manual car, and for PASM sport mode I can well enough press the button for myself. Worse, the clock actually gets in the way of my Garmin GPS mounting and I don't want it there. However, if Cayman Sport Chrono has effect (4) and (5) I would want to have Sport Chrono on the Cayman . But from all my reading, Cayman only has effect 1-3. Please comment.

If you drive a car with it, you can easily "feel" the difference while driving. To really see what I mean, accelerate with the sport mode "on" and switch it "off" while still accellerating with it floored. You will feel the car noticeably slow. I have heard the argument that you can press your foot down faster, but what happens when you hit the floor? Sport Chrono has some "additional" oomph. I don't think it's HP, but it definately gives you "more" throttle.

Doesn't sport mode also change PSM parameters so that it cuts in less often?

yes it does

yes it does. HOwever, we can also use our fingers to press the PSM defeat button.

I agree with Fadiboy - you should test drive a car and try it with and without - to me, it makes a big difference. brad

Yes you can - but PSM still lurks in the background and will still engage under certain circumstances - the threshold for those circumstances are still higher with SC on sport mode. brad

I've got the sport chrono option and when it's on there's a night and day difference versus when it's off. The car is definitely more responsive with sport chrono on and I'd highly recommend it as an option. I love driving with SC activated and coupled with PASM it makes for a very aggressive ride both on the road and on the track. Matt

I invite you to review our FAQ: http://www.planet-9.com/faq.php?faq=cayopt#faq_sportchrono

The map is shifted. Hitting the floor both With and Without sport chrono gives you 100% throttle. The throttle map function merely means, that at sport mode, you arrive at 100% with less pedal travel.

I have done a test drive WITH and WITHOUT. Sport Chrono 's throttle mapping DOES GIVE a more responsive throttle pedal, in that you arrive at max earlier. And contrary to some forum postings, it does not reduce the dynamic range of the pedal, since it is just a simple map shift to the left. However, if it is just a simple map shift, no problem, that I can do with my own mind It's the engine mapping which will promote Cayman 's sport chrono from a mere `macro' to a more meaningful `program'.

Thanks i read that. But the disclaimer: ' many things happen including ' does not address point 4 and 5 which happen on other Porsches. 4) Remap engine management to produce better response and shift cam timing to a more aggressive map, while HP remains the same 5) Increase HP and Torque using engine remap and cam map shift. Was hoping that someone here has a definitive answer on this.

From the Porsche Product Information Guide : I didn't see anything about cam timing.​ [/SIZE]

There are 4 levels of PSM intervention going from most to least intrusive: 1. PSM on SC off 2. PSM on SC on 3. PSM off SC off 4. PSM off SC on When PSM is "off" it will still intervene under certain defined circumstances, but intervention is later w/SC on, e.g., if SC is off when ABS for either front wheel is activated or if SC is on, when ABS for both front wheels is activated. This has been well discussed in a number of prior threads which included documentation from Porsche publications. Personally, for the track I find the throttle difficult to modulate w/SC on, but maybe I've had too little seat time thus far to get used to it. BTW, I think there's little debate that as a useful lap timer, forget SC.

read this, also from Porsche: the word - the engine dynamics change - implies some form of remapping, so I asked for clarification.

They are probably referring to SC's ability to hold the rpm's up more when shifting to aid in heel/toe, meaning a more free-wheeling engine feel.

SC reduces PSM intervention (in both on & off settings) allowing a skilled driver greater control, at/close to the limit. With PSM off & SC on the driver has the maximum control allowed by PSM. If, and that's a really big IF, a driver can exploit the difference, s/he will be faster w/SC. However, I'd guess few here can (& do) drive at that level. Walter Röhl does. SC changes the manner in which the rev limiter intervenes, again making it less interventional. Do a search & look at the published SC rev limiter chart which has been previously posted (& discussed ad nauseam )several times.

FYI I have heard Walter say that if you run up against PSM in sport mode you likely aren't doing something correct and that PSM is simply saving your butt from a bad manouver or words to that effect. I think there is a mistaken belief by a lot of people that they are somehow magically faster with PSM in the off position. How fast they are depends on how they drive and how the car should be driven in any given situation. I find when I've driving the line correctly and "smooth" with the car, PSM rarely comes on when in sport mode, and in fact the only time it seems to come on is when a wheel is slipping on a very tight and slow corner because the car isn't getting the power down via LSD. I expect LSD to fix that. Otherwise if I light up PSM somewhere else, it is usually because I've done something wrong (early apex'd etc.)

If PSM is interrupting the party, you're probably doing something wrong. If you've switched PSM off and then the computer kicks it back on, it's because it's saving your bacon in a big way! So playing devils advocate here, PSM off & SC on - let's the driver do bad things longer before the computer interrupts. I'm not thinking that's any faster! I don't mean to bust balls Dan, but I try stay OFF the rev limiter when I drive on the track - so I don't see that as a real performance improvement.

On the day when I purchased my '07 Cayman S , the sales rep told me that the regional rep from PCNA told her and other the other sales people there that the Sport Mode adds about 15hp. I asked her why there was no record of this anywhere and she didn't know. Later that night when I was picking the car up and she was going over the features, she said again that if I hit the sport button that it unleashes more power from the engine. I didn't want to argue with her about all this magic "power unleashing." But found it very strange that a Porsche sales person would throw this out there and actually say a regional PCNA rep mentioned it. That said, I've been driving exclusively in Sport mode now and it does have a very good feel too it, but it's no good if you're trying to just drive slow smoothly. I just wish that 1) I didn't have to hit the sport button everytime I gotin the car and 2) I could get the stop watch to stop on 00:00, closest I've gotten is 00:02. - Suneet

Was snake-oil an option? [On the day when I purchased my '07 Cayman S, the sales rep told me that the regional rep from PCNA told her and other the other sales people there that the Sport Mode adds about 15hp. I asked her why there was no record of this anywhere and she didn't know.] Suneet: Sounds like the sales associate engaged in some puffery.

Just select "reset" and leave. [I just wish that 1) I didn't have to hit the sport button everytime I gotin the car and 2) I could get the stop watch to stop on 00:00, closest I've gotten is 00:02.] Just stop the stopwatch and select "reset".

I'd take that one a bit further and say.......

I have PASM but do not have Sport Chrono . I frequently use PASM sport mode when I'm driving in fast, bumpy sweepers. It limits the wallowing effect dramatically. I seldom have PSM intervene unless I really scr*w up or I hit a wet patch. I don't miss the dash mounted stop watch, throttle or traction/stability or rev. limiter remap at all. I'm pretty heavy footed but have only hit the stock rev. limiter once. I didn't like it. Happy Motoring! John

From what I understand - and I'm sorry to say I have no reference for this - SC extends the redline a few hundred more RPMs, but when you hit it, the limiter kicks in hard - like bingo. With SC off, there's a lower redline, but the limiter is "softer" and lets you bounce of the redline, as opposed to shutting things down immediately. brad

I think SC is a real benefit on an autocross course where the time to push the throttle actually may matter- and allows less violent motions by the driver to accomplish the same thing. I'll also say that I can't duplicate the feeling of thrust (pushing me back into my seat) with SC off and just stomping the throttle, but maybe that's in my head... I am also happy with the big tach front and center (this is my 1st P-car). I can actually see the rpms at the shift point w/o distracting me from driving.

Your cracking me up! You debate minutia how, that in certain scenarios SC might be faster - but when rubber meets the road, you switch it off when you're on the track! Thanks for making my point for me! We need someone with a Traqmate in their car - someone who can show real data, not just conjecture. Till then, I remain unconvinced that an SC car is "faster". Do you think 997 GT3 owners spend their time debating whether SportChrono makes their car faster? I really doubt it. I'm glad you enjoy the SC system on the street. Porsche wouldn't sell as many cars equipped with it if there wasn't a market for it. I'm sure you're right - there might be a small "bump" in resale value or desireability for a car equipped with SC. It's been a fun thread, let's do this again next month!

I'm sure that an SC car is "faster", in my hands anyway... You know I think I said this about 18 months ago that SC can make you faster or slower depending upon: 1) The track configuration 2) How you use it or don't use it 3) Your skill with the throttle 4) Prevailing weather and track conditions. One item that tends to hold true for tight autox courses is that SC - ON and PSM - ON is the best combo because it allows you to experience momentary drift which is the fastest way to get your Cayman around a tight autox course. Turn PSM off and you'll go too far with the drift and lose time, turn SC off and you won't be able to feather the throttle fast enough to engage drift momentarily while avoiding PSM. I guess what I am trying to say is that there is no one right answer for all tracks and all situations, what you need to do is experiment to find the best combo for the track/course you are on and the prevailing conditions. Having something like a data acquisition system to plot your laps can be a big help in helping you determine what is the "right" setup for that day. K-Man S has spoken...

Huh? I guess I missed your point. I thought your position was that SC adds nothing to performance & can't yield faster laps. If so, my personal useage is entirely irrelevant. I leave SC off primarily because, at least at present, I prefer a "longer" throttle pedal. I also (presently) lack the requisite skill, balls or desire to fully exploit its elevated PSM level & tighter rev limiter. Perhaps you do too, but that's equally irrelevant to the discussion. The question is, can SC improve lap times? For the reasons mentioned, in the right hands, it can. This has been a theoretical discussion. I never suggested it makes you, me and everyone else a faster driver. Surely it's not your position that if a performance enhancement benefits just skilled track drivers, it's of no value? If so, I suggest that few track drivers & fewer street drivers fully exploit their Porsche's brakes, suspension or high performance tires. For most drivers the cars capabilites exceed their own. Out of curiosity, have you done any back to back comparisons driving a Cayman (or other new Porsche) w/SC on & off? I.e., have you had track experience w/SC or are you just talking theory? ... and yes, it's been fun, but it's already been done every few months. :cheers:

Guys, The difference in rev limiting is not actually a higher rev limit, but a difference between a 'soft' and 'hard' rev limiter. Let me explain. A hard rev limiter is just what it sounds like. At a certain RPM, the computer cuts all the vitals to the engine preventing it from revving any higher. These usually come on hard and abruptly because you go from full RPM, full power, to engine cycling on an off. A soft rev limiter is a little different. A soft rev limiter is really 2 rev limiters in one. Let's say the hard cut off is 7,200 RPM. Well, a soft rev limiter will usually kick in about 500 RPMs earlier by rolling the timing back many degrees from ideal. So, at 6,700, with a soft rev limiter, the computer starts pulling the timing back. This makes a noticeable flat spot that the driver can feel as a noticeable reduction in pull, indicating it's time to shift. Keep pushing, and you WILL reach the hard cut off. But you have essentially 500 RPMs of reduced power output as a warning/indicator. And, by the time you do reach the hard cut off, the timing is so retarded that it comes in much gentler because you are bouncing between reduced power and no power. When you switch Sport Chrono on, that soft cut off is removed and the engine is allowed to make full output all the way until you reach the hard cut off limit. Truthfully, this may actually mean that in Sport mode a Cayman does in fact make a couple hp more than in normal mode, but this will be minimal as at that RPM you are already past the useful torque slope. This is how many chip/software manufacturers show a hp increase. By replacing a soft rev limiter with a hard one, and by bumping it up a few hundred RPMs. All Caymans (regardless of SC or not) have only a hard rev limiter in 1st and 2nd gear, as to not adversely effect 0-60 times. Once you are in 3rd or higher, the soft rev limiter is there. Unless you have SC and press the Sport button. Then you have a hard cut off only in all gears. I have attached the Sport Chrono info from the Product Info Guide. It ammuses me how strongly people will fight to prove thier opinion on this.

GB, Thanks for the flow chart on Sport Chrono . I have been trying different combos, so it's good to see the layout. I like to push Sport, then PASM for more "agility" with less harshness when not on the track. Thanxxx for your feedback. Cheers...Mike