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"PASM" (Porsche Active Suspension Management) was an option on Porsches since at least about 2006. It's based on Bilstein Damptronic which uses an electronic valve in the shock to vary the damping.
I dyno'ed an 09 factory PASM front damper, results below, for varying terminal currents (about 600 to 1300 mA... I think I skipped one step though)
Some observations.
Huge dynamic range. Rebound at 5 ips varies over a 6:1 ratio.
In the softer settings, low-speed bump and rebound are symmetric, which I like.
These shocks are twin-tube. See large hysteresis at stiff setting.
Bilstein sell an upgraded set that are monotube.
TPC sell a programmable controller called the DSC that replaces the factory controller.
You can see it here
You can set each damper's stiffness as a function of cornering/braking/acceleration G's, and, in later cars, as a function of wheel position, and rate of rise of brake fluid pressure and TPS.
So you can do things like stiffen the outside front when powering out of corners to make the rear hook up better, or when getting on the brakes to prevent brake dive.
I know 949 are fixin' to go active... cool beans. I just with it happened 5 years ago!
09 Cayman S front factory Damptronic (PASM)
Last edited by JasonC SBB; 06-20-2017 at 08:03 PM.
Our current Xida Ace shocks have a very similar capability.
The control interface is the next unit to be upgraded. The Tractive fob actively adjusts pairs of shocks in response to dive/squat and roll left/right.
That DSC Sport unit works with our shocks. We want one. We just need a "Gentleman" customer to help justify a few.
How fast does the ACE valve respond from soft to stiff and back?
I have some ideas for a "comfort" setting if the valving real time adjustment changes rebound more than it does bump.
The Tractive ACE valve is the centerpiece of both the DSC control system and Tractive's own, simpler control system. The ACE valve responds in 6ms, in infinite steps. One neat thing we learned about the ACE valve is that due to it's physical configuration, it has a wider sweep than a manual adjust can achieve. On the ACE kits, we use this to range to allow almost zero damping on the low end. This gives amazing sharp bump response without the floating or lack of control after the bump that you would get with a manually adjusted damper. It's weird to be driving over knarly broken pavement with the car just floating like an SUV, then respond like a PTE points build with 1000/400 springs when you snap the wheel into a turn.
Current ACE kits for the NA, NB, ND and by Q1 2018, NC use the simple fob adjuster and standalone accelerometer based actuation engineered by Tractive. We have been in communication with the folks at DSC about doing a DSC control system for the ND. That process will begin in a few months with an eye towards having something in production for Q2/18.
The DSC system for the ND will be fully integrated into the CAN bus utilizing the following native sensor inputs/outputs:
Like the OP, the ND system would use the same PC based user interface for tuning. It is our vision to offer three basic "maps", Street, Sport Touring and Race. From there, an owner can get into the software and build their own maps. This system is not only more complex and expensive, there are precious few customers that would understand how to take advantage of the software's capabilities. For that reason, we entered the market ith the basic Tractive fob controller first.
On a side note, we're doing a DSC system for my C6 Z06. That's a one off project back burner item. It may become a "Xida ACE" to be distributed by us or maybe we'll have DSC sell it. That remains to be seen.
Does the ACE valve primarily affect bump, rebound, or both like the plots I posted?
I think they each have their pros and cons.
Having a separate valve for bump and rebound would be ideal.
As our Xida ACE systems filter into the market more and more people will have an opportunity to take a ride on them. It is truly eye-opening. We will have an ND & NB with Xida ACE at MRLS in October giving street rides.
Yarp. Not legal anywhere except Super Lap Battle/ GTA unlimited. :(
Actually... poking at the GCR, the specific wording SCCA uses against these kinds of things is absent in the GT tube frame classes. I wonder if that's why someone at the June Sprints was getting pissy at me looking at his car.
06-20-2017, 06:01 PM
Bilstein Damptronic dyno curves
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