PSM - How important do you think it is?
04-18-2008, 02:52 PM
#47
Three Wheelin'
04-20-2008, 12:00 AM
#49
Rennlist Member
I just spent 2 days at the track playing with the PSM, and frankly, I like it. It helped point out some bad habits I've developed over the years. After a few sessions of finding where and how the PSM kicks in, I was able to adjust my line and technique to prevent the PSM from kicking in - and turned some nice smooth laps.
When you do get over the limit, it really, really works at saving it. I was quite impressed.
04-20-2008, 12:51 AM
#51
Racer
It's certainly a great system and obviously is here to stay and helps cars move down the road extremely competently, but it shouldn't be a no-go if the car does not have it. Besides, we shouldn't be pushing it that hard on public roads anyway, right?
04-20-2008, 09:42 AM
#53
Three Wheelin'
Until you push it to the limit!!
I just spent 2 days at the track playing with the PSM, and frankly, I like it. It helped point out some bad habits I've developed over the years. After a few sessions of finding where and how the PSM kicks in, I was able to adjust my line and technique to prevent the PSM from kicking in - and turned some nice smooth laps.
When you do get over the limit, it really, really works at saving it. I was quite impressed.
I just spent 2 days at the track playing with the PSM, and frankly, I like it. It helped point out some bad habits I've developed over the years. After a few sessions of finding where and how the PSM kicks in, I was able to adjust my line and technique to prevent the PSM from kicking in - and turned some nice smooth laps.
When you do get over the limit, it really, really works at saving it. I was quite impressed.
My feeling is that it's unnecessary. If you get stuck with a car that has it it's good to know you can turn it off.
04-20-2008, 10:53 AM
#54
Burning Brakes
Join Date: Apr 2007
Location: MA, the cradle of random driving
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Where I live there is snow on the road 3 months of the year, sand on the road 5 months of the year, and frost heaves, broken asphalt, and potholes year round. This isn't the pacific west.
04-20-2008, 02:44 PM
#55
Cap'n Insane the Engorged
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To answer this question, you have to analyze the various functions of PSM and what they are intended to do. Then you can decide if they are really needed.
ABS - PSM controls and uses ABS, which I think we all would agree is a good thing. ABS remains active, even when the PSM button is turned off.
ABD and ASC - Automatic Brake Differential and Automatic Slip Control. ABD uses the brakes to act as an electronic version of a limited slip differential to keep drive torque going to the rear wheel with grip.
ASC is simply traction control, it closes the throttle if both rear wheels are slipping under acceleration. This is a function that can easily be replaced by some training of the right foot. A car with ASC should out accelerate a non-ASC car on slippery surfaces with 99% of drivers, because the computer will react faster than most of us. This could be important in a wet race where you want optimum traction in slippery conditions but is not as critical on the street, where you shouldn't be trying to maximize acceleration when the conditions are slippery.
ABD remains active, even when PSM is turned off.
EDC - Engine Drag-torque Control. This function is basically to counter trailing throttle oversteer which is what you get when you are near the traction limit in a corner and you lift, which begins to rotate the rear of the car. A well trained driver will use this characteristic of the 911 to get the car to turn in for a corner, so having an electronic aid to counter it is not always desirable. Of course, this feature can be turned off via the PSM button. On the street, you probably shouldn't be cornering fast enough where this function is engaged.
DDC - Driving Dynamics Control. Basically this system detects understeer or oversteer conditions and selectively brakes the appropriate wheel to counter the unwanted condition. DDC will also retard the throttle if you are badly out of shape and it can not correct by just using the brakes. Of course, if a car is properly set up, oversteer and understeer should be completely controlable through driver inputs with the steering and throttle. This is called car control and good, experienced drivers have learned how to do it. New drivers need to learn it. DDC could be useful on the street but if you're getting into it, you should probably just slow down.
ABS - PSM controls and uses ABS, which I think we all would agree is a good thing. ABS remains active, even when the PSM button is turned off.
ABD and ASC - Automatic Brake Differential and Automatic Slip Control. ABD uses the brakes to act as an electronic version of a limited slip differential to keep drive torque going to the rear wheel with grip.
ASC is simply traction control, it closes the throttle if both rear wheels are slipping under acceleration. This is a function that can easily be replaced by some training of the right foot. A car with ASC should out accelerate a non-ASC car on slippery surfaces with 99% of drivers, because the computer will react faster than most of us. This could be important in a wet race where you want optimum traction in slippery conditions but is not as critical on the street, where you shouldn't be trying to maximize acceleration when the conditions are slippery.
ABD remains active, even when PSM is turned off.
EDC - Engine Drag-torque Control. This function is basically to counter trailing throttle oversteer which is what you get when you are near the traction limit in a corner and you lift, which begins to rotate the rear of the car. A well trained driver will use this characteristic of the 911 to get the car to turn in for a corner, so having an electronic aid to counter it is not always desirable. Of course, this feature can be turned off via the PSM button. On the street, you probably shouldn't be cornering fast enough where this function is engaged.
DDC - Driving Dynamics Control. Basically this system detects understeer or oversteer conditions and selectively brakes the appropriate wheel to counter the unwanted condition. DDC will also retard the throttle if you are badly out of shape and it can not correct by just using the brakes. Of course, if a car is properly set up, oversteer and understeer should be completely controlable through driver inputs with the steering and throttle. This is called car control and good, experienced drivers have learned how to do it. New drivers need to learn it. DDC could be useful on the street but if you're getting into it, you should probably just slow down.
04-20-2008, 07:01 PM
#56
Ironman 140.6
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A car with ASC should out accelerate a non-ASC car on slippery surfaces with 99% of drivers, because the computer will react faster than most of us. This could be important in a wet race where you want optimum traction in slippery conditions but is not as critical on the street, where you shouldn't be trying to maximize acceleration when the conditions are slippery.
In my experience it cuts engine power (big time) to regain traction and it's very slow to re-apply power. The system seems to work best in extremely low traction situations. In medium to high traction conditions I find that it is far too aggressive.
04-20-2008, 07:57 PM
#58
I was driving aggressively on brand new rear tires, I forgot that there is a break in period for like 500 miles... PSM is great for blond moments like these. No offense to the blondes 
