Wayne Smith

I believe what got added in the 991 was shock (shaft) speed. That definitely is not on the 997.2.

The .1 cars need to have the G sensing added.

Also the controller is different for the .1 cars vs the .2 cars (for reasons beyond my pay grade, but I might guess it is CANBus related).

BLU997

I have purchesed a DSC unit for my 997.2 CS, but it has not arrived, so a little time to think about how to attempt to record & analyse the changes.
There are a few "seat of the pants" & "coffee spill tests", before/after impressions of the fabled DSC improvement on Utube, but nothing scientific, with recorded car ride data etc.
I checked on app store and there are a few specialised apps that can record in real time, the actual acellerometer data from your phone.
My Foxwell NT530 maybe able to see what's going on in real time 'data from the OBD.

.Any suggestions for a foolproof methos of comparing before/after ride performance with the DSC?

Spastblast

Nordschleife lap time?

No, it just depends on what you're looking for. Some looking for performance, some looking to improve comfort.

DesmoSD

Stock PASM w/out the DSC controller sucks.

Tom@TPC Racing

The literature posted by the OP in this thread has been posted in other threads from the past. The literature's description is accurate. Mostly. On the input side. I'll expand on this later. The literature was in the marketing material during the intro campaign of the 997.1 Carrera S back in late-2004 and has been in the owner's manual since. Back then we were primarily a full-time race car team racing GT3 Cup cars in pro class and was involved in mechanical 3-way and 4-way damper tuning and development. Obsessed by suspension technology, of course we were beyond excited when we first read the intro of the 997.1 active suspension system. So excited that we took delivery of one of the first newly released 2005 Carrera S and drove the car 300 miles from the dealer to a race track. That 300-mile drive was the break-in. With high expectations based on what we read the car was ran by a pro driver in both modes. We concluded that to get the best out the car in stock form the modes had to be switched for different parts of the race track while driving on the track. This exercise(totally not recommended for safety reasons BTW) showed us the output range of the dampers in each mode and what potential there is between the two modes. This done way back in 2005. Many drivers by now have experienced the two modes to be pretty binary; soft or stiff. Some drivers like it this way. Some drivers desire more. The inputs are on CAN(Control Area Network) as descripted by the literature. DSC gets all inputs from CAN as well. Although we never found the 3rd axis from the accelerometer on CAN on a 997.1 after a full year of looking. Whereas on the 997.2 was found in one day. In previous postings I have used stiffness percentages as examples. I should have clarify that that was to express a relatively limited output range in each mode of the stock car. The input data is all there. Except for the one axis we were unable to find. Anyway, for me, I want a wide output range that uses the fully capability of the dampers to the inputs on CAN. Like, I want the front dampers to stiffen up 50% when I stand on the brakes for anti-dive and have less body roll when I engage a 1.0g+ sweeper turn. Only the wide output range of the DSC does that.

wjk_glynn

Hey Tom,

Briefly what other differences are you aware of between stock PASM controllers on the .1 vs. .2 cars (3rd axis accelerometer aside)?

Basically what improvements (if any) do you know of between the generations of controllers (in stock configuration)?

Thanks.

Karl.

PS: I appreciate your product repaves the controller with your own solution...

Spastblast

Hi Tom,

Thanks for clarifying this for a newbie like me. So basically Porsche never fully took advantage of what could be done with their PASM controller. I mean, the input is there; they just didn't unlock the potential of mapping them to the outputs in the best way possible. I don't know when your DSC controller came out, but could it be a limitation of their 2004 electronics? That e.g. they couldn't do all these calculations fast enough with their hardware (while keeping it cost effective)? I've experienced their implementation to be very binary, as you say, and therefore thought the changes were only applied when pressing the button ('active' on button press) and not based on these dynamic conditions ('active' during changing circumstances).

Too bad the 3rd axis was never found in the 997.1 CAN bus data. I'm wondering if anyone else might have ever come across it, but I guess not.

Looking forward to getting the DSC controller and accelerometer when my budget allows it. Great that you created that. It looks to be one of the most rewarding upgrades one can get for a 997.

saxonite

You'll really enjoy it. I drove mine for 3 years before I got the DSC and absolutely love it. The ride is more compliant on road but when really pushing the car, especially on track, the chassis is much more composed.

Tom@TPC Racing

From my experience the control strategy is very similar between the gens.
The more noticeable changes for me are the different damper/springs/sway bar config between the gens and the different model within the gen.
DSC had been an extremely popular and well-liked product because it fills the gap between the two modes and beyond the two modes to the inputs in real time.

Tom@TPC Racing

Been evaluating all the stock models with electronic suspension from 2004 to present. The stock 2 mode strategy has been consistent. Owners of 997.2, 991.1, 991.2, and 992 can attest to this. Some like it the way it is. Some want wider output range and more dynamic input-to-output. The stock damper/springs/sway bar package improved by every gen.

Liste-Renn

I don't think looking at an app is necessary to notice the substantial delta in handling/ride between the two controllers. With a 5-minute plug and play, you can swap boxes and drive the same route back-to-back with each controller to compare them.

Easy peasy.

With virtually any other suspension change, that is impossible without a shop, a mechanic and access to a nearby race-track or a particularly challenging road. I found one of the latter...

My PASM controller comparison test:

I drove Latigo Canyon Road in the Santa Monica mountains four times RT (80 miles) with the OEM, then swapped to the DSC box and repeated the same 80-miles of twisting, descending/ascending (with hairpin switchbacks) linked 2nd and 3rd gear turns.

(Seems like about 50 turns and 25 up/downshifts in 10 miles.)

I have not found a better road to explore chassis performance envelope boundaries in a 911. Every variety of weight transfer possible is experienced in those 10 miles up and 10 miles down. Off camber braking downhill switchbacks are notorious for exposing suspension limitations.

And, as we all know, driving a 911 well is about controlling/exploiting the chassis weight transfers. Hence Porsche has developed PASM, PDCC, PADM, PTC, PTV and when all else fails, PSM (Please Save Me).







Latigo Canyon Road Malibu




The dynamic A/B comparison between the boxes was profound.

I echo Tom's description of the DSC transforming the PASM from the binary SOFT/STIFF into a continuously variable reactive system that, with either mode selected, adjusts real time to multiple chassis sensor inputs. The anti-dive and, to a lesser extent, the anti-squat feature are dramatic improvements in straight line dynamics. And similarly the lateral g-forces that induce lean are mitigated by the greater range of valve adjustment to the individual shocks.

The overall ride also feels more compliant in both NORM and SPORT modes. Chassis upsets from road imperfections are minimized, keeping the contact patches loaded/planted at all four corners. I had a major complaint with the OEM box not adjusting well to mid-corner bumps, humps and heaves. A stiffer suspension is not advantageous when encountering those imperfections at speed pre/post apex. With the DSC controller, the compliance noticeably improves mid-corner grip compared to OEM.

Pretty cool stuff for $1200.

Bruce In Philly

Excellent..... I would like to add two items the DSC controller does for me: 1) No more expansion joint "bangs" (or less so), and 2) Less rear-end heaving/moving when accelerating in bumpy turn. This heaving when you accelerate in a bumpy turn is partly the controller and mostly the engine mounts. The DSC controller helps with this handling flaw.

Peace
Bruce in Philly (now Atlanta)

Spastblast

Thanks for sharing your experience.
FYI: It looks like prices in Europe are around €2500 (incl. accelerometer), so I guess it's cheaper for me to buy a plane ticket and pick it up in the US