Question in regards to PSM
02-15-2007, 11:48 PM
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Question in regards to PSM
I am a new member here and I had asked this question on another board and some suggested that I should try this question out here.
A little back ground I have a 2001 996 C4 with PSS9, H&R sway-bars and I am running Michelin PS2. I have the EVO-V flow intake paired with the GIAC chip flash, I am thinking I am getting 300 hp to the ground or there about.
Question in regards to PSM, I ran a Hook on Driving event the entire day at Laguna Seca with the PSM on, it never once kicked in? Even when the instructor took me for a hot lap ride in my car he never got it to come on. Never once did the tires break loose I think it was just set up great with the PSS9s and H&R sway-bars. Just stuck like glue to the turns. The tire pressures never got above 41psi after initial setup.
I will say I did get the ABS to kick in on a couple of hard breaks but I was surprised the PSM didn't. Any thoughts? Not enough HP to break it loose? I know the PSM works because it would come on all the time with the P-zero tires the car had a couple of weeks ago before the change.
A little back ground I have a 2001 996 C4 with PSS9, H&R sway-bars and I am running Michelin PS2. I have the EVO-V flow intake paired with the GIAC chip flash, I am thinking I am getting 300 hp to the ground or there about.
Question in regards to PSM, I ran a Hook on Driving event the entire day at Laguna Seca with the PSM on, it never once kicked in? Even when the instructor took me for a hot lap ride in my car he never got it to come on. Never once did the tires break loose I think it was just set up great with the PSS9s and H&R sway-bars. Just stuck like glue to the turns. The tire pressures never got above 41psi after initial setup.
I will say I did get the ABS to kick in on a couple of hard breaks but I was surprised the PSM didn't. Any thoughts? Not enough HP to break it loose? I know the PSM works because it would come on all the time with the P-zero tires the car had a couple of weeks ago before the change.
02-16-2007, 12:11 AM
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If this was your VERY first event you may have not had the car close enough to the limits to kick the PSM at all. You could also have been driving a "perfect" line and there was no need for the PSM to activate your car is AWD and pretty well set up!!! Hopefully you will get some pro instructor answers soon!! tom
02-16-2007, 12:43 AM
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This is from the stats I know for the 987/997 version of PSM, but I would assume the thresholds are slightly less aggressive for your 996:
PSM will activate if the slip angle on the front wheels exceeds 7 degrees or the difference in rotation between the front and rear wheels exceeds 5%. Sport Chrono Plus in sport mode loosens this a little bit but I don't know how much.
If you do donuts, PSM will stop you. If you do a burnout, PSM will stop that too. On the current generation, braking hard enough to activate the ABS will reactive PSM if it's been disabled. I have heard that PSM in the 986/996 will reactivate if you even hit the brakes but I can't confirm this.
Most likely you were just driving well within your car's limits and the system left you alone. As a DE-weenie I always leave mine on and it usually leaves me alone unless I screw up. Or use a curbing to rotate the car, PSM, she no like that.
PSM will activate if the slip angle on the front wheels exceeds 7 degrees or the difference in rotation between the front and rear wheels exceeds 5%. Sport Chrono Plus in sport mode loosens this a little bit but I don't know how much.
If you do donuts, PSM will stop you. If you do a burnout, PSM will stop that too. On the current generation, braking hard enough to activate the ABS will reactive PSM if it's been disabled. I have heard that PSM in the 986/996 will reactivate if you even hit the brakes but I can't confirm this.
Most likely you were just driving well within your car's limits and the system left you alone. As a DE-weenie I always leave mine on and it usually leaves me alone unless I screw up. Or use a curbing to rotate the car, PSM, she no like that.
02-16-2007, 12:49 AM
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Tom is too kind. If the PSM didn't kick on, you weren't going fast enough, and the instructor was respecting your car and treating it gently. I would guess you didn't exceed 8/10ths. It isn't power that kicks the tail out at racing speeds, it is trail braking. If you brake late enough into a turn to initiate rotation, the PSM will activate, and slow you down. Power plants the tail in our cars, except in full wet conditions. Then you need very aggressive throttle to overcome innate understeer(with the PSM off). Try again. AS
02-16-2007, 01:10 AM
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Originally Posted by cviles
This is from the stats I know for the 987/997 version of PSM, but I would assume the thresholds are slightly less aggressive for your 996:
PSM will activate if the slip angle on the front wheels exceeds 7 degrees or the difference in rotation between the front and rear wheels exceeds 5%. Sport Chrono Plus in sport mode loosens this a little bit but I don't know how much.
If you do donuts, PSM will stop you. If you do a burnout, PSM will stop that too. On the current generation, braking hard enough to activate the ABS will reactive PSM if it's been disabled. I have heard that PSM in the 986/996 will reactivate if you even hit the brakes but I can't confirm this.
Most likely you were just driving well within your car's limits and the system left you alone. As a DE-weenie I always leave mine on and it usually leaves me alone unless I screw up. Or use a curbing to rotate the car, PSM, she no like that.
PSM will activate if the slip angle on the front wheels exceeds 7 degrees or the difference in rotation between the front and rear wheels exceeds 5%. Sport Chrono Plus in sport mode loosens this a little bit but I don't know how much.
If you do donuts, PSM will stop you. If you do a burnout, PSM will stop that too. On the current generation, braking hard enough to activate the ABS will reactive PSM if it's been disabled. I have heard that PSM in the 986/996 will reactivate if you even hit the brakes but I can't confirm this.
Most likely you were just driving well within your car's limits and the system left you alone. As a DE-weenie I always leave mine on and it usually leaves me alone unless I screw up. Or use a curbing to rotate the car, PSM, she no like that.
02-16-2007, 01:14 AM
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Originally Posted by Alexander Stemer
Tom is too kind. If the PSM didn't kick on, you weren't going fast enough, and the instructor was respecting your car and treating it gently. I would guess you didn't exceed 8/10ths. It isn't power that kicks the tail out at racing speeds, it is trail braking. If you brake late enough into a turn to initiate rotation, the PSM will activate, and slow you down. Power plants the tail in our cars, except in full wet conditions. Then you need very aggressive throttle to overcome innate understeer(with the PSM off). Try again. AS
So based on your experience should I learn to drive with the PSM on or Off?
02-16-2007, 09:11 AM
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LEAVE IT ON!!!!
Don't be fooled by anyone here that says a newbe should shut it off. They won't be writing a check if you hit the wall. Yes, a racer and most DE'ers who run very hard could be hampered by PSM (this has been discussed ad nauseum here), it will save your bacon. There's no good reason to turn it off until your car control skills are so good that you know when PSM will kick in before it does.
AGAIN, LEAVE IT ON!!!
Don't be fooled by anyone here that says a newbe should shut it off. They won't be writing a check if you hit the wall. Yes, a racer and most DE'ers who run very hard could be hampered by PSM (this has been discussed ad nauseum here), it will save your bacon. There's no good reason to turn it off until your car control skills are so good that you know when PSM will kick in before it does.
AGAIN, LEAVE IT ON!!!
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02-16-2007, 10:43 AM
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Originally Posted by cviles
As a DE-weenie I always leave mine on and it usually leaves me alone unless I screw up.
Don't touch that button! It will spank you when you deserve it. Few casual drivers will find it hinders a day at the track.
02-16-2007, 10:59 AM
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I have said before: whenever I ride with a student with PSM, and they choose to leave it on, any time it intervenes I bring them into the hot pits.
Why?
Beacuse PSM has a relatively high threshhold for intervention, and when it is noticed by driver and/or passenger, it has just save the driver from something MAJOR. And we can use this as a learning tool!
Why?
Beacuse PSM has a relatively high threshhold for intervention, and when it is noticed by driver and/or passenger, it has just save the driver from something MAJOR. And we can use this as a learning tool!
02-16-2007, 11:06 AM
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OK, I will leave it on that was the direction I was leaning anyhow since I never saw it kick in with pretty aggressive driving. It seems there is a large margin between when PSM kicks in and when it doesn't, I didn't really see the point of turning it off especially during a none racing event like a DE.
I personally like the idea of a bacon saver!
I personally like the idea of a bacon saver!
02-16-2007, 12:14 PM
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There was a good article in one of the mags, don't remember which one where Hurley Haywood talked about how good a learning tool PSM is and why they use it at the Porsche Experience School.
02-16-2007, 12:14 PM
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I've found (in my 987S) that PSM has 3 moods...
It can be subtle. There are times when I have been intentionally playing with the system to see what it will do, and if I wasn't paying real close attention I would never notice a subtle adjustment that I know *I* didn't make. Over and done with before the light even has time to flash.
It can be overt. Unless you're dumb, deaf, and blind you can't miss this. The system will cut power and brake one corner of the car. The light flashes and you know your electronic copilot has put his hand on the controls. If you're good (well not so good as to avoid it) you can see this one coming.
It can be an in your face drill instructor. Even dumb, deaf, and blind you can't miss this. I had PSM practically lock up a wheel to save my ***. This was two years ago, and I had even less of a clue how to drove my new Porsche and did something stupid in an off-camber turn on an unfamiliar street. Times like this you thank God for PSM.
Remember, it's usually the guys that claim their stability system is "slowing them down" that need a flatbed before the day is done. Unless you know how the system works and can predict it will intervene before you do something, leave it on. A fraction of a second is a lot cheaper than bent sheetmetal and medical bills.
It can be subtle. There are times when I have been intentionally playing with the system to see what it will do, and if I wasn't paying real close attention I would never notice a subtle adjustment that I know *I* didn't make. Over and done with before the light even has time to flash.
It can be overt. Unless you're dumb, deaf, and blind you can't miss this. The system will cut power and brake one corner of the car. The light flashes and you know your electronic copilot has put his hand on the controls. If you're good (well not so good as to avoid it) you can see this one coming.
It can be an in your face drill instructor. Even dumb, deaf, and blind you can't miss this. I had PSM practically lock up a wheel to save my ***. This was two years ago, and I had even less of a clue how to drove my new Porsche and did something stupid in an off-camber turn on an unfamiliar street. Times like this you thank God for PSM.
Remember, it's usually the guys that claim their stability system is "slowing them down" that need a flatbed before the day is done. Unless you know how the system works and can predict it will intervene before you do something, leave it on. A fraction of a second is a lot cheaper than bent sheetmetal and medical bills.
02-16-2007, 12:27 PM
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Originally Posted by 1957 356
There was a good article in one of the mags, don't remember which one where Hurley Haywood talked about how good a learning tool PSM is and why they use it at the Porsche Experience School.
By the way I love your Avatar with the right wheel lift, would you call that a PSM moment?
02-16-2007, 12:28 PM
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Originally Posted by 1957 356
There was a good article in one of the mags, don't remember which one where Hurley Haywood talked about how good a learning tool PSM is and why they use it at the Porsche Experience School.
Wasn't it in Pano last summer? I seem to recall this.
Hell, if Hurley endorses it, that's really all we need to know!