[dcharnet]

I track a 14 BS MT with Sports Chrono.

Rev matching, very useful, only activates in Sport +.

I cannot turn off PSM in Sport +. If I try to turn off PSM while in Sports +, Sports + deactivates.

With PSM on, I cannot rotate the car quickly on corner entry by easing off the brake pedal while turning to facilitate momentary controlled oversteer---a standard advanced trail braking technique in road racing.

Thus, I cannot combine rev matching with "PSM Off." Apparently I have to choose one or the other.

Is this designed into the system by Porsche, or do I have a malfunction?

Can it be overridden so that I can rev match with PSM off?

 

[wagzhp]

I can't swear to this, but I'm pretty sure i can dissable PSM and have sport+ active. But note that I also have PDK, the programming might be different between PDK and manual cars.

 

[dcharnet]

Thanks, but the issue is why this MT car (not PDK) will not rev match with PSM off.

I do recall reading somewhere that PSM was less aggressive in Sport + mode. But is still always "on."

 

[Westcoaster]

Thanks, but the issue is why this MT car (not PDK) will not rev match with PSM off.

I do recall reading somewhere that PSM was less aggressive in Sport + mode. But is still always "on."

IIRC, yes PSM is less aggressive in Sport+, it's threshold of intervention is higher but never really off so depending what the sensors pick up PSM will intervene. As for rev matching I never heard that there was a way to turn on in the 981 without turning on Sport+

Maybe time to learn/practice rev matching the old fashion way...

 

[dcharnet]

I have years of rev matching in prior race cars, including two cars with non-synchro boxes (Hewland and Ford Rocket Box) which when mastered, added to the challenge and fun. The idea appeals to the purist vintage racer still lurking in me, but I prefer the function to be automatic, Also, the 981 throttle and brake pedal would need mods.

 

[Westcoaster]

I have years of rev matching in prior race cars, including two cars with non-synchro boxes (Hewland and Ford Rocket Box) which when mastered, added to the challenge and fun. The idea appeals to the purist vintage racer still lurking in me, but I prefer the function to be automatic, Also, the 981 throttle and brake pedal would need mods.

Gotch ya! If I understand the situation correctly in the new Spyder/GT4 they have separated the ability to turn rev matching on/off irrespective of the suspension and traction control settings, perhaps they figured out people wanted this choice...

 

[dcharnet]

I wonder why they engineered it like this on the 981 in the first place.

Safety, probably.

Good thing, probably.

 

[987Hermes]

PSM does switch to a less intrusive setting with sport mode, and more so with sport+. Regardless, I am able to turn off my PSM with sport+ on. The thing is, with PSM off, the car will turn off rev-matching in sport+, or so I've read.

I don't know for sure because I habitually rev-match manually even when sport+ is on.

 

[dcharnet]

Right, that was the point of my post---the car turns off rev matching in S+ mode when PSM is off.

Ironic, because dynamic imbalance (and thus the possible need for PSM in a sliding car) can be a consequence of poorly matched downshifts.

Perhaps the potential shock loads exceed the design parameters of PSM.