Cupcar

Am I correct? I just realized that every Porsche model but the GT3 comes standard with PSM = Porsche Stability Management, a system that uses sensors and individual wheel braking to control yaw angle. This means the car can't be drifted if a certain angle of yaw is exceeded without the car trying to correct itself with PSM.

Furthermore, I find that the PSM system cannot be fully turned off since even with the on-off switch as it will still be switched back on if the ABS is triggered during braking.

How could you have any fun at the track if each time you brake for a corner the PSM is turned back on if you hit the ABS for an instant ?

Also, the Sport Chrono package is necessary if you want to set the system tor higher yaw angles before intervention and a higher ABS threshold before it re-engages if turned off.

I don't know about you, but I think these two trends of "big brother" driving the car for you at the track and having to pay extra to get a "sports car" by having to buy something like the Sports Chrono package when you are buying a sports car in the first place suck, or am I missing something?

I wonder how long it will be before even the GT3 has PSM!!!!

mooty

you actually have to do a lot to get psm to come back on (if you turn it off), you can trail brake smoothly wihtout it come back. you sure can't hang your *** out as much as you can with non psm cars, but you can still do it.

i am not saying psm is good, but just saying it's not that bad, yet.

there is a way to kill it off completely. no, it's more complicated than pushing a button or two. a good race shop that really knows 997 987 cars can do it.

icon

psm on all porsches thread LINK

the regulation states that it can be completely disabled.
hopefully porsche will offer the ability in the future.

Cupcar

Thanks! Boy did I come late to the party, I completely missed that thread on this topic. Reading the NHTSA letter I can see now that 100% of all Porsche cars will have PSM by Sept. 1, 2008.

I can't find the link to the regulation stating that it can be permanently disabled, can you provide?

Cupcar

Thanks!!! I found the link it is here http://dmses.dot.gov/docimages/pdf97/414636_web.pdf

This is very interesting reading. The pages on turning the PSM (NHTSA calls this ESC for "Electronic Stability Control") off start on page 64.

For fear some will disable the system completely, on/off switches will be allowed.

The mode that "off" selects so far has been at the discretion of the manufacturer.

Some manufacturers merely decrease but not eliminate the function i.e. the same option that Porsche offers with the Sport Chrono package's "Sport Mode".

Others turn if off totally. Porsche has elected to turn it off completely when off, but to re-engage when ABS is activated.

Personally I would like a "normal mode" (default) where PSM is agressively engaged with low yaw limits, a "Sport" mode where the yaw/ABS limits are increased or a "Track" mode where it is off completely never to re-activate.

It is precisely because of the on/off button that Porsche had to petition the NHTSA for an exemption for the dashboard lignt to indicate that PSM is off. To get the exemption Porsche are offering 100% vehicle equipment with PSM by 2008.

MJSpeed

there's a race shop in Canada that currently campaigns a Cayman in some sort of racing series and had an article in Panorama (I think) that discussed all they did to prep the car for racing, which included de-activating PSM altogether...IIRC it was simply by removing a fuse of some sort...not as complicated as originally expected.

mooty

MJ, i spoke with ernie many times (he's the one racing the canadian yellow cayman S). he liks to have the psm in the car, he turns it off, but it's not fully disabled. he said in the rain, it's like cheating ;-)

however, there is a way to kill it off 100%.

Nordschleife

I have a switch and two pieces of wire, looks oem when fitted. But its also worth having the ecu modified to let you lfb to your hearts content without disabling the PSM.

R+C