GT3 Racer

Is it possible to over-rev a PDK equipped car?

Bob Rouleau

No it is NOT possible unless you have a very very steep hill long enough to get the car over 200 MPH in top gear

Edgy01

I think you'd have a heck of an argument in your favor with Porsche if it did!! I would love to see them try to weasel out of that one if an engine over revved. The only way I can see it happening is if the car is entirely out of gear, and someone pushes the accelerator to the floor with no regard to the RPMs. Once it gear, it should never over rev, by design.

OldGuy

You may be able to bounce if off the rev limiter. But electronics will save you.

Carrera GT

While it's possible, in Sport Plus, to downshift to 1st at the redline, it seens not to be possible to get 1st gear anywhere near close to the redline under full brakes (I mean on the track, literally as much force as you can apply with your leg or both legs if need be.) I've played with this for dozens of laps and the car consistently refuses to go to 1st (and will even upshift to 2nd once PSM intervenes.)

PDK also has some "rules" about a downshift into 1st with certain degrees of steering input. I presume that most of the constraints on getting 1st pertain to stability and PSM rather than PDK being worried about the engine speed. The conflict I see is that PDK can only disengage both clutches, it couldn't intervene with the brakes to protect the engine (compromising the primary objective of protecting the occupants of the car ...)

I have by no means come to understand how it all works together "in extremis" but it has some very specific "out of bounds" conditions where it will do whatever it deems necessary to keep the car in a "plausible" envelope of all its sensors (the one it fears the most is yaw, but PDK and PSM have no qualms about four wheel drifts, understeer or oversteer, they just want to see those transitions occur within reasonable degrees of rotation.)

Anyway, suffice to say I have no doubt it's possible for PDK to allow the engine to overrev into at least some of the code ranges in traction-related conditions, but I doubt it's possible to "fool" PDK into a "money shift."

OldGuy

What he said^

fpb111

After watching the technical presentation in this video and the subsequent Master tech explanation, one might have a better idea of how a Porsche PDK trans works. Be sure to pay attention to the the section where the Master Technician explains about using the proprietary tester and billable hours.

It almost looks like Porsche and Mercedes were sharing some ideas Mercedes brought back from Chrysler.

http://www.break.com/index/understan...cabulator.html

savyboy

[QUOTE=Edgy01;7041358] The only way I can see it happening is if the car is entirely out of gear, and someone pushes the accelerator to the floor with no regard to the RPMs.QUOTE]

Nope, it hits the limiter, right at redline. You can't over rev in neutral/park.

mambodoc

Would love to see the video but cannot access it...

mambodoc

Belay that...break.com has some cool PDK tracking videos... Thanks man!

Carrera GT

http://www.break.com/index/understan...cabulator.html

(still makes me laugh uncontrollably)

larrytrk

I believe my lunar waneshaft is out of phase!!

OldGuy

Hey thats the same definition I give my kids when they ask how something works.
I keep going until:
A: they leave the room or
B: they ask their mom another question

No HTwo O

What if you spun the car, on the track for example, and spin the engine backwards??? Could it over-rev?

Bob Rouleau

I'll hazard a guess that unless you were going faster backwards than forwards before you spun the answer is "no".