dbbarron

With all this talk of stock or bilsteins v. traktives relative to response time, I was wondering if the 100ms response rate of the stock dampers was 'too slow' for various driving conditions. Accordingly, I took a video segment from an AX this weekend and isolated a relatively fast slalom with relatively high G forces to figure out whether 100ms is a long time relative to the course or otherwise.

The answer is 'otherwise' - 100ms appears to me to be a fairly short period of time relative to the motion of the car and particularly the changes in pitch of the vehicle (I've inserted a static horizontal line you can view against the horizon to give a sense of pitch changes). The 100ms stock update rate (although not nearly as good as the tractives) certainly seems relevant to real conditions.

The frame counter is about 33ms per tick, so every three ticks is 100ms.

The video runs at 1/10 normal speed.

Here is a link to the video (2011 997.2 GTS; SPASM; 'Sport Plus' damper setting; Cup 2s):

bmwtye

Is something in the works with JRZ?

DSC Sport

Pretty much all shock companies have either developed, or are developing, an electronic control valve. The DSC Sport controller can be used to control all electronic valve designs.

Tom@TPC Racing

Thanks for taking the time to put together and share the video. I am in agreement with you that 100ms is suitable for many driving situations. Which is why DSC has been so wildly successful as a plug & play management device for OEM electronic shocks. DSC is cost effective approach to get the most out of the electronic shocks that came with your car. The accelerometer senses the g-force before the chassis even reacts so DSC commands the shocks to manage the movement in a predictive manner, in many situations ahead of the shocks' reaction time.

The value in the Tractive DDA shocks is not only in the much quicker reaction rate, the patented bi-directional valve produces wider range of compression and rebound damping, and can react to commands during mid-stroke(Whereas the OEM shocks have to complete the stroke. This why DSC mapping is different between OEM and Tractive, in order to stay ahead of the chassis in a predictive manner).

When DSC users decide to upgrade their shocks, a Tractive DDA coilover kit is comparable cost to other top-tier brand mechanical coilover kits. Tractive DDA kit includes front & rear spherical bearing top plates, axial bearings, hats, springs, and tool kit. Build quality and consistency are top-tier, superior to OEM assembly line. For those who wish to upgrade electronic shocks Tractive DDA is currently the pinnacle choice.

DSC and OEM shocks remain as a solid "Stage 1" combo, concurred by hundreds of positive reviews from users...we get new positive feedbacks almost everyday! For some, Stage 1 fills the need. For others, the full monty is a necessity.

floatingkiwi

There are still G anomalies Left to right in the 0.6G front G Table line in the GT3/GT4 map available from the website. Is this intentional?

DSC Sport

No, this was not intentional. Thank you for pointing it out. The effect of the anomaly was minimal if any at all, but it has been corrected and is now available on the website.

smasraum

I was reading info all over the 'net including the DSC and TPC websites. I kept finding myself wondering how this system was better than the stock system since the stock system is supposed to provide a lot of the same functionality.

"The system automatically selects the appropriate damper hardness based on
the PASM programme selected and the driving condition identified.
The Normal programme offers comfortable settings with low damper forces.
Special control algorithms in the PASM software modules enable the chassis to
offer greater active driving safety in extreme driving situations, even with the
Normal programme. To increase driving safety at higher speeds, the dampers
are automatically switched to a harder damper setting as speed increases.
The dampers switch to a hard characteristic when Sport mode is activated.
This offers superior agility and excellent steering precision on uneven surfaces.
If the system detects an uneven driving surface in Sport mode, it immediately
switches to a softer characteristic to improve contact with the road surface.
PASM selects the optimum damper setting for this softer characteristic from
the Sport map.
Since extremely hard damping is not always the ideal solution in every driving
situation (depending on the driving surface, the vehicle may start to bounce or
shift), the intentional overlap between the Normal and Sport maps allows a
noticeably soft setting to be selected if necessary. The customer gets an
“active sports chassis” which automatically responds to the actual road surface
and switches from a hard, sporty damping setting to a comfortable range as
necessary. PASM switches back to the original characteristic as soon as the
road surface is smooth enough."

Per Porsche, the stock PASM has Lane Change, Verital-control, Lateral acceleration, Brake and Load-change modules, which all change the characteristics based on various situations.

As I read, I thought, hmm, that sounds like what TCP/DSC is doing. I was so glad to finally get to the post above (and another earlier post that used slightly different numbers). I have to say that based on the explanations and various reviews, I am very excited. You should include a bit more detail, similar to the above post to give more indication of why DSC is better than factory PASM. I think the current page just says that the dynamic range and rate of response is changed. It would be nice if there was a bit more detail about how range and rate is increased.

I have noticed that if I have PASM set to Sport, and I hit a bumpy section, I feel the rear get really unsettled and bouncy. The same area with PASM set to normal seems to provide better traction and allow a lot more throttle and speed. Based on what I've read, DSC would improve the sportiness of the normal mode and the stability and functionality of the suspension in the Sport mode, especially on less than ideal surfaces.

Does anyone know if there is a thread similar to this but with more action on the mid-engined front? Boxsters and Caymans (Caymen? ) I haven't seen many posts about the Coxsters other than some GT4 posts, and it would be nice to hear from them since that's what I'm driving.

One other thing, when on the website there is a link to the accelerometer that's broken.
http://www.dscsport.com/?p=3095
"All 997/987 PASM-equipped Porsches. NOTE: all non-turbo .1 vehicles require the purchase and installation of a DSC Sport 3-axis accelerometer."

dbbarron

I am a recent purchaser of DSC for my 997.2 and had the same questions as you regarding why Porsche would leave anything on the table as the response conditions claimed for stock PASM sound very much the same as DSC. However, although I do not yet have any track time, from some limited time on the street I can say that DSC SPORT stock mapping mode is way softer in normal conditions than Porsche SPORT mode. Nonetheless, you can very clearly feel it stiffening up on braking and I assume in other conditions not possible on the street. Definitely more 'active' than stock PASM - more in a few weeks after a couple of events.

For whatever reason, Porsche felt the variability offered by DSC was not appropriate despite having the same potential capability. Probably some compromise between driving uses and marketing intention as are all things.

db

dbbarron

997.2 with SPASM and Sport Chrono. DSC box just installed.

In 'normal mode', I can switch DSC modes using the PASM button ('Normal/Sport')
Same of 'Sport Mode'.

However, in 'Sport Plus', DSC seems to be locked on Sport mode so I can't switch mappings. Is this normal? Is there a way around it?

I'd like to stay in Sport Plus, but be able to switch the mappings for AX for some testing/optimization of the suspension settings.

db

smasraum

Interesting. For the folks that only have normal and sport, the change to 2 modes was an improvement. Now there are lots of folks that have 3 modes. I wonder what the fix will be for that? Back to a third mode? Needing to have 2 versions of the software (2 and 3 mode). It sounds like maybe the programming for cars with 3 modes is a bit different than the 2 modes, and not covered by the update to get rid of the blinking lights.

Larry Cable

So did the OEM PASM controller display this behavior?

I very much doubt that this is a (dis)function of DSC ... based on my experience PASM mode is always selectable independent of other (sport chrono) settings ...

smasraum

Good call, I was thinking pasm, but this is about the sport/sport+ mode (which does engage PASM, but is different.)

Larry Cable

exactly! - SC mode normal/sport/sport+ *does* select normal/sport PASM also (initially) but you can independently *also* select PASM normal/sport regardless of the SC mode selected (at least that is my experience with a variety of 911's) ...

To the best of my knowledge 2 or 3 mode DSC on either the 997 (GT3) or the 991 operates in the same fashion as the OEM PASM controller ... i.e the is no mode lock function dependent upon SC mode selected.

So this is either a (new/different) behavior on the 997 Carrera or the DSC (which I seriously doubt)

dbbarron

I just completed my first AX event using the DSC controller. Driving 997.2 GTS, SPASM, Cup2's and cup car LCAs with -2.8/-2.3 camber settings.

First video is AX a few weeks ago stock controller, Second video is yesterday with DSC. Different course layouts (but same location) and I was driving much better yesterday, but both my co-driver and I both felt that that there was better stability and lateral grip using the DSC controller (unmodified 997 sport mode programming from DSC). If you watch the video I think you will notice considerably less lateral roll. The greatest seat of pants subjective difference is in the slaloms - just felt like you could carry more speed and the car (specifically the tail) had somewhat less tendancy to get loose when you pushed it. On second thought - ditto that comment everywhere! Good upgrade.

Another event next week.

Stock Controller


DSC Controller

db

nwGTS

Congrats for winning the Gold Cup class at Road America, guys! I assume you're using the DSC in your Cup car if it's even allowed. If so, Is anyone else using the TPC DSC besides you? Would you even sell it to them if they did want it? I suppose Platinum and Gold don't compete.