What is it?
The DSC module is a direct replacement to the OEM PASM control box which works with the various sensors in our cars and the vehicle's onboard computer to adjust damping rates to provide as close to optimal adjustments based on road conditions and driver inputs.

Making the switch
As mentioned by others, the OEM PASM control box is located in the upper area of the passenger footwell, just below the glove compartment behind a foam like housing. Simply remove four plastic screws, locate the OEM PASM box, (I had to pull back the upper section of the carpet in the passenger foot well area but not by much and it sticks right back) and replace. The boxes are held in place by a set of clips. It took me 25 mins to switch it out but only because I was going extra slow to avoiding causing any permanent damage. It could be done in under 10 mins.

Does it work?
Boy does it work! First, some details on my car. It's a 997.2 TTS on stock suspension. I had no major issues with the car's suspension but at high speeds on the highway certain bumps would "shift" the car and allow for a slight loss of traction, quick steering responses at speed would induce some 'roll', hard acceleration and braking induced some "squat" and "dip" respectively and our notoriously bad roads in NJ/NY often made selecting PASM Normal the default choice, which exacerbated all of the above. PASM sport helped with the roll and squat/dip but made the ride jarring on certain sections of road.

Enter the DSC module!! To say the difference is noticeable immediately is an understatement. The majority of road imperfections are absorbed, making for a much more compliant ride but at the same time the damping mechanism is equally improved which makes the car more planted around bends/corners. The car simply feels more balanced...the slight squat under hard acceleration is gone which might not make the car any faster but it sure does make the car more composed!

On the highway, I felt more contact with the road, especially at high speeds going over road imperfections. I conducted a series of tests on some familiar on/exit ramps and the feeling of control at speeds +5mph to +10mph higher than I normally feel confident taking those ramps was impressive.

The Modes
Mode 1 - feels much better than PASM Normal. The much improved ability to absorb bumps in the road while retaining a fair amount of stiffness for cornering etc. is great. The PASM button remains steady lit on in this mode.

Mode 2 - is noticeably stiffer than Mode 1 "Normal" and IMO slightly stiffer than PASM Sport. This is masked however by the DSC module's ability to retain its absorbing effects on bumpy roads!! Incredible, at first I thought Mode 2 was not as stiff as PASM Sport (due to the still compliant ride) but a quick run through a familiar 270 degree exit ramp cleared things up! I could take the ramp quicker and in more control than I could in PASM Sport! The PASM button blinks twice rapidly intermittently in this mode.

Mode 3 - honestly I couldn't discern much of a difference between Modes 2 & 3 but I suspect my 45 mins test drive had a lot to do with that! I suspect one needs to really push the car for the effects of Mode 3 to be more apparent. I know Mode 3 is certainly stiffer than Mode 2 as the quarters I have in the "ashtray" space in the center console jiggled slightly more than in Mode 2 on certain roads, but that's about the extent to which I could discern differences. The PASM button blink three times intermittently in this mode. For those who "complained" about the blinking, I did not notice it unless I looked down and even then it wasn't a bother.

Mode 1 "tamed" my local roads, Mode 2 is the sweet spot for my sensibly aggressive driving style and I'll explore Mode 3 further at my next track day. One added benefit I noticed during testing was that the selected Mode remains selected when you turn the car off/on! As we know PASM defaults to Normal on start-up. Similarly, normally hitting the Sport button automatically engages PASM Sport, with the DSC module your selected Mode is unaffected by the Sport/Sport Plus button. A nice feature. Switching between modes is as simple as pressing the PASM button.

This module simply inspires confidence behind the wheel, the technology truly makes a remarkable difference in handling and road feel (comfort). If I had to sum it up for someone wo doesn't currently own one, I would say the feeling is comparable to that you have immediately after installing new tires after rolling on 2/32" - 4/32"! That WOW, the car handles better, is quieter (less jarring), stops better, performs better feeling. It's a bit like that but here it's the suspension mechanism that's improved!

Thanks to Harris for a super quick response and quick shipping! Honestly, this is a mod I wish I'd done months ago! I look forward to enjoying this for a while...

When Santa keeps delivering into mid-January!


The DSC module


A few shots vs. the Porsche OEM PASM box




UPDATE (4-13-15)

I conveyed my favorable impressions of TPC's DSC module on the street and promised an update once I had the opportunity to test the DSC module on the track. Well thankfully NNJR's PCA DE season kicked off in April with a 2-day track event at historic Limerock Park in Lakeville CT! For those who haven't been, Limerock is a fast 1.52 mile track with quite a few technical corners including the infamous "Big Bend", the "Uphill" and the ensuing "Diving Turn" which leads to the front/main straight. The update covers primarily "Mode 3", which as folks may recall I really couldn't discern a significant difference over "Mode 2" on the street.

The Conditions
The event was held on April 8th - 9th. The weather was cold on both days (sub 45 degrees) and compounded by intermittent rain on Day 1. As you can imagine, Day 1 was extremely tricky as the combination of cold and wet tested even the most advanced drivers. Day 2 was dry, thankfully, but still cold! No need to mention the traction issues that cold weather presents on tires (before warming up).

The Performance
The DSC module shined on both days! While Day 1 was cold and wet, with speeds moderated by savvy drivers for obvious reasons (a few of us did hit 125mph on the main straight nonetheless), the DSC module in Mode 3 did a fantastic job in the corners of adjusting the damping rates to not only keep the car level (minimizing weight transfer on the outside tires) but also aiding in maintaining maximum surface contact by the tires. This was confirmed through conversations with fellow drivers on similar street tires who reported squishy and tire travel/loss of traction in the wet! The TTS just plowed through it. My Day 1 instructor commented on the handling in the wet asking what combination of suspension and tire set-up I was running! I gladly informed him (stock suspension, Michelin PS2 w/ DSC module!).

Day 2 was where the DSC module excelled! In the dry, every driver felt confident and was inclined to push their cars a lot harder. For reference, I hit 148 mph on the main straight before "Big Bend", a ridiculous top speed, so I was told, for Lime Rock. The DSC module did an excellent job maintaining the car's balance going into "Big Bend" following the heavy braking required to hit the first apex after 140mph+ speeds on the main straight! That balance allowed for similar control into the 2nd apex (Big Bend is a long double apex corner, hence the name). Each corner was equally well tamed. So much so that for the last session, I was 'signed off' to run solo (I was in the lower intermediate Yellow group and solo runs are reserved for the Upper intermediate White run groups and above). My instructor expressed that much confidence in the car...and driver!

Full disclosure requires that I mention that I am fully aware that my TTS has ALL the electronic gizmos that Porsche engineers designed to keep my car from going 'off track' (e.g., stability management, traction control, torque vectoring and even dynamic engine mounts to offset the engine's rear-weight bias in turns) and I am aware that each of these features played a role in the car's amazing stability during high-G turns. That said, given that I had tracked the TTS at the Monticello Motor Club with the stock OEM PASM box I could easily tell the difference in handling afforded by the DSC module.

The DSC module is a KEEPER!

A few pics...





UPDATE (11-29-16)

There comes a point, (if you track your car with any frequency,want to improve your lap times and generally have a desire to keep up with the ‘competition’) when you will need to upgrade some of the stability and suspension bits in our 997.2 TTS! These 991 GT3’s and ever increasingly present Cayman GT4’s are hardto keep up with through corners at the track (although they’ve got nothing on aTTS in the straights)! Solution: a visit to TPC racing for (i) TPC Racing adjustable sway bars, (ii) track alignment and (iii) DSC module firmware update.

DSC module firmware update – the technical details of the DSC module firmware update were quite extensive when speaking to Mike Levitas (more on Mike later). The two cosmetic changes that are immediately apparent are (1) the DSC module now only has 2 modes (instead of 3) and (2) the lights on the PASM button are either OFF (mode 1 or “Normal”) or ON (mode 2 or “Sport”) so no more full ON, 2 blinks and 3 blinks to indicate the selected mode. This is similar to the stock PASM lighting system, but that is where the similarities end, the underlying programming is quite a feat to behold. I will try to explain but will likely not do it justice.

First, the module’s source algorithm was completely reversed.The initial algorithms started with “street” car settings and were subsequently adjusted to incorporate “race” car characteristics in modes 2 & 3. The revised algorithm STARTS with “race” car settings and comfort is progressively dialed-in. According to Mike, where the change is primarily felt is that now, there is no compromise in the transition from comfort to sport. Apparently in the prior version, there were ‘gaps’ in the algorithm which compromised how the system engaged the damping response (Mike showed these to me as empty boxes in the algorithm). These no longer exist and have been addressed. The revised algorithm now also incorporates variables for speed sensitivity and also improves the braking application.

The difference between modes 1 & 2 is simply that in mode 2 “Sport” the engagement threshold is lower (i.e., the damping stiffening occurs much sooner/quicker when the module senses or detects aggressive application at each wheel). I will leave it to Mike to answer specifically why the 3 distinct modes were eliminated, however on the street, I find that the new mode 1 “normal” is a nice more responsive blend of the old modes 1&2, while the new mode 2 “Sport” is a more responsive progressively linear version of the old mode 3. Each performs great in their respective applications (street and track).

In a nutshell, the prior version was intuitive, now the DSC module is almost telepathic in its ability to respond to both road surface imperfections and driver inputs.

Mike and the guys at TPC Racing are true suspension and carguys who refine their products on both the track and on the street. These guys know their stuff. I am told that the revised firmware vastly narrows the gap between our 997.2 TTS damping characteristics and that of 991 GT3’s. The chassis certainly felt more connected to the road at VIR after the upgrades. Mike is truly passionate and extremely knowledgeable. Having the opportunity to spending time talking with him plus getting a peek inside the fantastic algorithm operating the DSC module was a privilege and a lot fun. I’m certain I’ll be back to TPC Racing for more “goodies” as I strive to continue keeping 991 GT3’s and Cayman GT4’s in my rear view mirror at the track!

TPC Racing adjustable sway bars – This is basically TPC Racing’s 997 Stage 1 suspension kit without the Drop Links (the 997.2 stock drop links have sufficient tolerances that upgrading to adjustable drop links weren’t deemed necessary + additional benefit was being able to retain the rubber insulation boots which keeps the cabin quiet). The goal for the upgrade was to achieve greater cornering balance and stability to enable me carry faster speeds through corners (specifically higher corner entry speeds).

Track alignment – the goal here was simply to dial in more/max negative camber, particularly in the front tires to increase the contact patch thus increasing the tire grip/limit of friction to combat understeer characteristics mid-corner.

 

Great write up! Will be installing mine soon as well. Will compare my experience with yours.

 

Great write up! I am glad to hear that you are enjoying your car!

 

Would the improvement be more desirable if new springs are installed? If so, which springs would you recomend Eibach or H&R? Thank you.

 

You will notice improvements with stock or modified suspension. If you were to install springs, I would recommend the Eibach springs.

 

Thanks 808c2s. I look forward to reading about your experience. If it is anything like mine, I have no doubt that you will be impressed.

Thanks Harris for a fantastic product. IMO, Mode 1 is how PASM Normal should have been from the factory.

 

Can someone please show me where the module is located?

 

He described it in the first post

"the OEM PASM control box is located in the upper area of the passenger footwell, just below the glove compartment behind a foam like housing. Simply remove four plastic screws, located the OEM PASM box, (I had to pull back the upper section of the carpet in the passenger foot well area but not by much and it sticks right back) and replace. The boxes are held in place by a set of clips. It took me 25 mins to switch it out but only because I was going extra slow to avoiding causing any permanent damage. It could be done in under 10 mins"

 

Gladly, however I'm in the office right now . If no one responds by the time I get home, I'll take a picture and post it for you.

If you look at the spot above where a passenger's feet would normally be, you should see a dark grey foam covering with 4 plastic screws. Remove the screws and foam cover and the OEM PASM box should be visible in its bracket with the wires attached/plugged in. I had to peel back some of the adjacent carpet (near the top of the passenger footwell) in order to safely remove the module. Simply pull back on the bracket clip to release the module. Hope this helps.

 

If I had only pulled the trigger on it last year. The Canadian to USD is now 1.21!!!

 

Tell me about it. My shopping list has shrunk for this upcoming summer with the useless peso, I mean dollar we have.

 

I just wanted to add a little clarification for Jako. Once the foam panel beneath the glove box is removed, the carpet that needs to be pulled back is on the right side of the passenger footwell. I was uncomfortable peeling this carpet panel down, but with some persistence it did come loose and it was then just a matter of unplugging the old and plugging in the new - easy beasy, and the carpet easily pushed back into place. If I recall accurately, someone posted pictures on a thread awhile back. A search may help.

 

Great post...I love how my car is modded to 2015 standers....feels new..this is a must have mod....just to add to your great info...the car dosent drive rear engined anymore ....like you said great balance and I'm sure your picking up big time on track on confidence alone....can't wait to go out for a ride again...

 

Here you go,

Beneath the glove box, the dark area is the foam like cover, which needs to come off first. The carpeted area to the right of the foam cover is where you need to peel back to access the OEM PASM box



Here is a shot of the module in place, what you see at the bottom is the carpet peeled back. It goes right back into place however when done. Note the black plastic clamps which hold the module in place...be careful not to snap them (although they are fairly sturdy).

 

Right on the money BK Boosting! I feel like I'm closing the gap on the 991s. When I test drove a 991 50th anniversary edition I was really impressed by how compliant the ride was, compared to the 997 TT's I had taken on test drives. The DSC closed that gap nicely, basically I get the benefit afforded by the 991's longer wheelbase without giving up the tactile feel of the 997's crisp steering response and smaller turning radius on the shorter wheelbase.

The 991TTS had more power, my FVD tune closed that gap, the 991 had a more compliant ride, the DSC module closed that gap, the exhaust note was slightly better in the 991TT (not by much) and in the 50th anniversary car w/ PSE glorious, the Europipe crushed that gap! All that's left that I really miss is the updated interior (including the dash cluster which has quite a bit of information on the far right gauge). I can live with that. I still prefer the 997 exterior styling to the 991, so no real longing there (although I saw a GT silver '15 TTS at my dealer on Saturday which made me look twice ).

Just loving the 997.2 TTS more and more!