991ers who go track PSM On, Sport, or Off?
03-03-2019, 07:06 PM
#16
In previous cars (non 911s) I always drive on the track with partial stability control. I have taken my Targa 4 GTS to the track once now. I left PSM on and had car in sport plus and PDCC on. I never felt stability contol do anything or saw any lights. However, I wonder if my excessive brake pad wear had something to do with PSM. The last couple weeks since my track day, I have been putting PSM in sport. My goal is to see if and when I feel a difference when I do some spirited runs. I did one yesterday and not much to report. No negative effects. It felt a little loser overall though. I intend to try it next track day in sport.
03-03-2019, 07:15 PM
#17
Burning Brakes
Wear was even all around. Nothing funny about wear just seemed excessive. Ran a lot of long sessions and only 20-30 min between 30-40 min runs. I think a lot of it is just real hard abuse and sustained heat. Its just one of those things I would like to figure out as to not spend a boat load on pads all the time. Next track day should help determine. GM cars always flashed stability light when it kicked in and killed power on corner exit, which I did not feel at all. Often I would forget to change settings when starting a session and it was just obvious real quick when I forgot.
03-03-2019, 07:35 PM
#18
Wear was even all around. Nothing funny about wear just seemed excessive. Ran a lot of long sessions and only 20-30 min between 30-40 min runs. I think a lot of it is just real hard abuse and sustained heat. Its just one of those things I would like to figure out as to not spend a boat load on pads all the time. Next track day should help determine. GM cars always flashed stability light when it kicked in and killed power on corner exit, which I did not feel at all. Often I would forget to change settings when starting a session and it was just obvious real quick when I forgot.
On the pad wear subject, I usually monitor, the front vs back, and the left vs right rear.
Ideally if you're mostly out of the PSM, you should probably be going with 2 or maybe 3 pairs of fronts per each pair of rears. Having to replace front vs back at the same frequency is one indicator of things not going so well.
The rear, left vs right, that could be a PTV thing, especially if you're going to tracks that are the same direction (clockwise or counterclockwise) all the time or going to a specific track that has a lot more right turns vs left (or vice versa). My understanding of how PTV works is that you can't turn it off as it's assisting the rear diff at corner entry, so especially in corners that ask for a lot of rotation it's literally impossible to not trigger the PTV if you're driving at pace.
Another bizarre thing I used to monitor was the evenness of wear on the same pad, especially on the rears. If you do end up riding PSM/PTV all over the track in addition to regular track brake loads, it usually ends up with the brakes overheating at which point you might be going above the operating temps of the your pad compound and the leading edge of the pad starts melting a bit faster than the back side.
YMMV.
03-03-2019, 07:55 PM
#19
Pro
Thread Starter
PSM on does wear out pads faster, especially the rears in my experience
03-03-2019, 08:00 PM
#20
Burning Brakes
You're probably doing fine. There's no way to not spend a boatload for brakes and tires in this specific activity (or maybe I couldn't find it), I'd get that thought out of your head to avoid future frustration
On the pad wear subject, I usually monitor, the front vs back, and the left vs right rear.
Ideally if you're mostly out of the PSM, you should probably be going with 2 or maybe 3 pairs of fronts per each pair of rears. Having to replace front vs back at the same frequency is one indicator of things not going so well.
The rear, left vs right, that could be a PTV thing, especially if you're going to tracks that are the same direction (clockwise or counterclockwise) all the time or going to a specific track that has a lot more right turns vs left (or vice versa). My understanding of how PTV works is that you can't turn it off as it's assisting the rear diff at corner entry, so especially in corners that ask for a lot of rotation it's literally impossible to not trigger the PTV if you're driving at pace.
Another bizarre thing I used to monitor was the evenness of wear on the same pad, especially on the rears. If you do end up riding PSM/PTV all over the track in addition to regular track brake loads, it usually ends up with the brakes overheating at which point you might be going above the operating temps of the your pad compound and the leading edge of the pad starts melting a bit faster than the back side.
YMMV.
On the pad wear subject, I usually monitor, the front vs back, and the left vs right rear.
Ideally if you're mostly out of the PSM, you should probably be going with 2 or maybe 3 pairs of fronts per each pair of rears. Having to replace front vs back at the same frequency is one indicator of things not going so well.
The rear, left vs right, that could be a PTV thing, especially if you're going to tracks that are the same direction (clockwise or counterclockwise) all the time or going to a specific track that has a lot more right turns vs left (or vice versa). My understanding of how PTV works is that you can't turn it off as it's assisting the rear diff at corner entry, so especially in corners that ask for a lot of rotation it's literally impossible to not trigger the PTV if you're driving at pace.
Another bizarre thing I used to monitor was the evenness of wear on the same pad, especially on the rears. If you do end up riding PSM/PTV all over the track in addition to regular track brake loads, it usually ends up with the brakes overheating at which point you might be going above the operating temps of the your pad compound and the leading edge of the pad starts melting a bit faster than the back side.
YMMV.
03-05-2019, 03:16 AM
#21
Pro
Thread Starter
I have never felt endangered by driving with PSM. I grew up with 600hp+ V8 cars with live axles. The 911 is composed, polite and refined by comparison, no matter its power. I've had it more than a little sideways but adding some throttle and steering out of the slide got the car right back in line with no additional drama (on track obviously).
03-05-2019, 10:50 AM
#22
Racer
991.2 Turbo S. I meant to say "without." Usually the first thing I do when I get into my car is turn PSM to "sport chassis." As far as I know it still does some intervention but it's very minimal.
03-05-2019, 11:12 AM
#23
Pro
Thread Starter
thanks for the correction. PSM Sport definitely gives a alot of room to slide
03-05-2019, 11:16 AM
#24
Three Wheelin'
03-05-2019, 03:32 PM
#26
Rennlist Member
PSM Sport on when available, PSM on in cases where it isn't. It's rare that I choose PSM off (mainly due to inside rear wheel slip that's bad enough that the considerable benefit of PSM is outweighed).
I find that PSM doesn't interfere much if ever with my driving style, allowing for a bit of slip angle and/or leaving it to me to make corrections before it intervenes. If I wanted to be big sideways, that would be another matter—but rear pads are cheap compared to bodywork or worse. There are plenty of very experienced drivers who have wadded up really nice cars without PSM. I bet they wished they had it in those instances…
I find that PSM doesn't interfere much if ever with my driving style, allowing for a bit of slip angle and/or leaving it to me to make corrections before it intervenes. If I wanted to be big sideways, that would be another matter—but rear pads are cheap compared to bodywork or worse. There are plenty of very experienced drivers who have wadded up really nice cars without PSM. I bet they wished they had it in those instances…
07-09-2019, 11:20 AM
#27
Instructor
hi i'm picking up a 997.2 c2s pdk with sport chrono plus soon, and i'm trying to learn about the car settings before it arrive.
came from a e90 m3 with dct, where the suspension hardness, level of stability control, throttle mapping, and dct shift strategy can all be configured independently.
looking at the 997.2 controls, seems like pasm has a separate button, and psm has a separate button to turn it completely off, regardless of if the car is on normal / sport / sport+
but lets say i'm just driving on public roads, if i want to have the pdk on the most aggressive / fastest shift setting (to enjoy some nice downshift rev-matching noise and a little kick in the back up-shift), and psm on the most conservative / safe settings (which i think is responsible whenever driving on public roads), and conservative / linear throttle mapping (i feel that all these aggressive throttle mapping makes throttle modulation harder, and prefer more linear mapping), looks like it is not doable? because only way to put pdk in aggressive mode will be using sport / sport+, which will at the same time enable aggressive throttle mapping and aggressive psm mode?
came from a e90 m3 with dct, where the suspension hardness, level of stability control, throttle mapping, and dct shift strategy can all be configured independently.
looking at the 997.2 controls, seems like pasm has a separate button, and psm has a separate button to turn it completely off, regardless of if the car is on normal / sport / sport+
but lets say i'm just driving on public roads, if i want to have the pdk on the most aggressive / fastest shift setting (to enjoy some nice downshift rev-matching noise and a little kick in the back up-shift), and psm on the most conservative / safe settings (which i think is responsible whenever driving on public roads), and conservative / linear throttle mapping (i feel that all these aggressive throttle mapping makes throttle modulation harder, and prefer more linear mapping), looks like it is not doable? because only way to put pdk in aggressive mode will be using sport / sport+, which will at the same time enable aggressive throttle mapping and aggressive psm mode?
07-11-2019, 12:03 AM
#28
Race Car
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I've been driving 911's aggressively for 44 years now and been an instructor since 1996. So I grew up on cars that had no computer input, it was all seat-of-the-pants. If you allow me to go back into the Good Old Days, I can tell you of all the cars I have track driven, a 911 was the most diabolical by a large margin. With that engine hanging over the rear, a sloppy driver, or one who didn't understand the dynamics of that layout, the car would bit you in the butt if you mis-handled it. Look at 911 wrecks from the 70's / 80's / 90's and you will see more are ***-end-first hits because owners would lift going hard into a corner. The rears on these early cars would snap around and go back-end-first into the Armco. HOWEVER - once you learned to drive a 911, you could really make them move and nothing could stop with them raging up to a corner, as all that weight in the back gave you ten or twenty more feet into the corner when hard on the brakes. But a lot of people did wreck their Porsches, it was a real issue.
Modern Porsches have tamed-out these handling characteristics with much improved suspensions and electronics to save the driver from mistakes. With everything engages, you can ham-fist a modern 911 around a track with little consequence. When you start turning things off however, some of those old rear-end-swap-happy characteristics come back into play. My advice then, is to leave the electronics ON until you learn the car well. And going 90 mph into a corner is not that place. Go to some autocrosses, where the speeds are half that and turn off the electronics there - see how the car feels. Orange cones are far more forgiving than Armco. Once you have it mastered at autocross, then start disabling the electrics at the track. Unless you have Torque Vectoring or AWD on your 911, you'll find you'll be spinning that inside rear pretty quickly with everything off anyways. I always disable my electronics on track days, though sometimes I forget and can be heard swearing under my helmet about it...lol
Modern Porsches have tamed-out these handling characteristics with much improved suspensions and electronics to save the driver from mistakes. With everything engages, you can ham-fist a modern 911 around a track with little consequence. When you start turning things off however, some of those old rear-end-swap-happy characteristics come back into play. My advice then, is to leave the electronics ON until you learn the car well. And going 90 mph into a corner is not that place. Go to some autocrosses, where the speeds are half that and turn off the electronics there - see how the car feels. Orange cones are far more forgiving than Armco. Once you have it mastered at autocross, then start disabling the electrics at the track. Unless you have Torque Vectoring or AWD on your 911, you'll find you'll be spinning that inside rear pretty quickly with everything off anyways. I always disable my electronics on track days, though sometimes I forget and can be heard swearing under my helmet about it...lol
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07-11-2019, 12:21 AM
#29
Rennlist Member
PSM sport can be really fun, but its almost like nothing is there to stop you if youre too hot on a corner. Once the booty lets go, its chris harris time and its scary. I can control a slide at low speed but not track speed if the back end snapped out. I leave psm on mostly but it punishes the rear brakes. I feel like psm sport is a good way to get your agricultural driver’s license if youre going full send and not greatly familiar with the track and its surfaces.
Last edited by Rennolazine; 07-11-2019 at 12:01 PM.
07-11-2019, 11:26 AM
#30
I do PSM off at autox, but leave it on for track days. I am not brave enough on track to turn it off, especially when the consequence is going into a tire wall. And honestly the only time I feel it intervening is when I turn in too early and fast, and the rear starts to come around too fast, at that point I’m off of the line I want to be on anyway. Corner exits are easy enough to open your hands up early and stay ahead of the rear tires.