Bruce In Philly

2009 C2S 113K MT Coupe

I purchased and installed the DSC TPC PASM controller a few weeks ago..... and made a 600 mile trip in addition to many miles on local roads.

Summary: Wow, it fixes most of the things I disliked about my C2S handling and ride. Highly recommended....... if your concerns were as mine. Installation takes all of 5 minutes, requires no tools, and no brain.

Who is this for?: I see two types of customer: 1) Those who are disappointed with the handling and ride (me!) and, 2) Those who want to make the ride and handling "better".

For #2 make it "better", I really have no comment or recommendation about this software change. Some folks want to improve or change track performance... others just like to tinker.... some want "track like" performance for the road..... others are just neurotic and do this for entertainment. I don't track my car so I can't comment here and beyond this, tweaking your car is deeply personal to only you. When someone notes "better", I shut down.

For #1 the disappointment, if your concerns were similar to mine, this is just what we were looking for.

What I didn't like about 997.2 PASM: For folks who read my threads, you know I have peppered my comments that I didnt like the car's ride or handling and always thought my 2000 Boxster S was a better set up. Here is what I don;t like about my 2009 C2S PASM
- Expansion joint "bang" The ride seems too hard when it shouldn't be. I am not referring to a firm ride but a hard ride. Sports cars should be firm... my Boxster S was but it never banged or slammed on sharp bumps.
- Uneven turn "wag and hop". The back end and front (to a lesser extent) will hop around and wag when I pull into a turn with uneven surface, press the gas...... the back end feels like the engine is moving around or something..... it is just not right and can be a bit surprising. I suspected my engine mounts so I replaced them with new Porsche units.... no improvement... some said it is the overall bushing compliment.... whatever.

Said another way, the handling is harsh when it shouldn't be and soft when it shouldn't be. I am no chassis expert so this is about the best I can describe.

My use of Porsche PASM is normal mode most of the time, Sport when I am on the interstate. Sport on the highway makes the car nice and stable... but darn the "bang!" on seams and joints.

DSC Software performance summary: In short, it softens the ride most of the time (both Normal and Sport mode) but quickly hardens the shocks when it is needed... really cool. I find Normal mode a bit too soft as the front and rear can float away over humps (not bumps).... I ride in Sport mode now ALL the time.... yes, Sport is way softer for just cruising down the road than even Porsche Normal was. I do put it in Normal if the road is chopped up or I am bouncing down a gravel road doing my photography. I love this system.

Best thing? No BANG or Wag...... they nailed it.... the car handles really well now.

Some info from DSC guys There are tons of information on the forums so do some research... I will add some here given my interaction with their staff. First, Mike, the owner of DSC / TPC is a race car owner and driver .... from their website "Since 2001, Michael has won 12 races in the Rolex Series, finished 2nd eight times, finished 3rd 10 times and racked up an additional 25 top-ten finishes. " These guys are not a shop making shiny exhausts and other eye candy go fast bolt ons. Mike said that there is no reason a sports car ride should be harsh...... the Porsche PASM system (actually it is Bilstein's Damp Tronics) is just not tuned properly.

Further, the 997.2 system that is built into our cars is not being fully utilized by Porsche. The system is dynamic in that there is a Normal and Sport mapping that changes the dampers based on various factors... however they use the system as a singe channel damper.... in other words, all four shocks are changed in the same way at the same time...... but, Porsche's system is actually a four channel system... and DSC takes full advantage of this changing only the shocks it needs to.

I talked to the guys on the phone before I purchased the product and then stopped down to see them in Jessup MD last week and got more information now that I had the system installed for a few weeks. They did note that they get some concerns that Normal is too soft and there is some internal disagreement about how soft they should be off the shelf. But here is some good news: They will provide you with a file you can upload that makes a firmness adjustment to the stock setting... just call them.... or ask them when you order the box.

If you are a tinkerer.... they provide software that is massively cool and it allows you to change all the parameters yourself.... I have no desire to do this as I am really happy with the system out of the box... they will also tell you what to change to take out the bit of float for slower driving.

They noted that the system sniffs the CAN bus and pulls in speed, G-force in three axis, brake pedal position, throttle position, wheel position..... not sure if that is all and then tightens/loosens up the particular shock(s) as needed. Wow, cool stuff. Of course Porsche is doing this, this is not a DSC invention but, DSC takes advantage of the four channel system like Porsche inexplicably didn't do, makes use of the system's softer settings that Porsche does not drop down to, and of course has simply a different tune that Porsche.

The system interacts with the Porsche dash and displays Normal or Sport message and lights the switch led as appropriate. What I really like, is that the DSC system remembers your last setting so when you start the car, it comes up in the mode you like.

Another big plus is that if you don't like it, it takes literally 5 mnts to swap out the unit for standard, and there are no tools needed. Then you just sell the unit and recoup most of your cost. How can you beat this? Talk about low risk.

BTW, they noted that given the success they had with Porsche (they are a big Porsche shop), they are now making this system for other makes and now working on a system for the Camaro. If you think you want to install this sytem in any other car, you really can't as every make uses a different format for their communications protocol even if they are using CAN.... DSC still has to sniff the data feed and pick it apart to pull out needed information and this R&D time and money.

More about my perspective: I want you, a perspective buyer, to understand where I am coming from in the hopes it helps you make a decision. I have a friend who is neurotic like me and is always buying/selling cars and then immediately starts tweaking the suspension.. at my house with my help. I never had the same taste in performance and ride as he but I learned two things from all this wrenching: 1) it is expensive in both money and time (fun though!), 2) you really don't know what you will end up with until you are done... then you are stuck with it until you swap out to the next configuration. Yes some coilovers have compress/rebound adjustments, but these on not conditional as the computer is. You can get a good idea if you are talking to someone experienced with suspension configurations, but I don't believe you will ever match tastes. Again, I am not talking about track performance, but taste in road performance... something that is very personal.

When it comes to taste, I suspect I am unique in that I keep the DSC module in Sport mode 90% of the time. I do this because I like Sport of course, but I purchased and want a sport car.... I want a firm, controlling ride. I don't want a BANG BANG ride nor a waging tail. These active suspension system are unbelievably cool and sophisticated.... I just don't know what Porsche was thinking when set this car up or why they didn't use the full four channel capabilities built in to the car..... my Boxster S rode more like a sports car than this C2S and never had that bang or wag.

Anyway, while not cheap, this unit is way cheaper in both money and time than swapping out parts.... and you still can swap out parts if you want.... and you can sell this thing and get most of you money back..... and you can tweak the crap out of it using a laptop and their customer software.

If you are unhappy with the suspension, like I was, I highly recommend this product.

Quick warning: When you read the forums, you will have to wade through a ton of irrelevant stuff as the software evolved quite a bit since its introduction.

Disclosure: I put new tires on ... went from worn out Michelin Super Sports to the new 4S and I find the 4S a bit softer. To try and normalize for this change, I swaped the Porsche PASM box back in to compare. The swap takes a whole 5 mnts and requires no tools.... you can do it out on the open road... just pull over, pull the key, and swap. If the tires change the ride by a factor of "2" the DSC sofware changes it by a factor of "20"... no real tire issue here.

For those thinking about making your suspension "better": I noted I can't provide a recommendation for you but..... is sure seems to me that screwing around with software is easier and heck of lot cheaper than installing new coilovers. On top of that, you have infinite tweaking ability. The DSC website has a forum where users like you can upload their favorite programs and some tuned for various tracks. If this doesn't do it for you, swap the old system back in and continue on with your original plans... no harm no foul.

Peace
Bruce in Philly

Useful Links:

TPC and DSC are the same guys

http://www.tpcracing.com/about-us.html
http://www.dscsport.com/

You tube has a ton of stuff.. user and DSC produced

https://www.youtube.com/channel/UCwn...eXJPr-4ULbOdoQ

Check out their software tutorial... amazing....

Presto

fantastic review. This is on my to do list for sure. Heard only good things about it.
i see 2 websites selling it. I'm guessing one is reselling it, not sure which one

http://www.dscsport.com/porsche/#997

http://www.tpcracing.com/dsc.html

Bruce In Philly

They are the same company in the same location and the same guys. Just call the number for either... I ordered over the phone.

Peace
Bruce in Philly

Wayne Smith

I'm glad you pulled the trigger on this purchase Bruce. Thank you for the detailed report!

rhinoman

That's a good review, if I didn't already own one I'd have bought one based on your comments as I too wasn't fond of the standard ride. I've only driven my car once since fitting, and it was wet and raining so only really tried normal mode but its so much nicer and more composed.

Bruce In Philly

You had this system for a while now Wayne, why not provide us with your commentary?

BTW, they will provide you with another file to address any concerns with softness you or others may have. They told me the Bilstein system in our cars has a wider range of softness values than Porsche used.... the DSC "baseline" is pretty soft and can be set a bit higher but still softer than Porsche's choices. DSC told me that this baseline is then modified when certain thresholds are crossed such as speed, G-force, brake pedal, etc. etc. This baseline setting will not effect the rest of their program.

Peace
Bruce in Philly

Wayne Smith

I have written a review within another post.

DSC uses higher current drivers to get faster response than PASM. Bilsteins will respond faster than OEMs.

A good friend acquainted me with the term Skyhook suspension. With independent stiffening on the loaded side or end of the car it does seem like an outside force is at work. That has taken me a while to get used to.

I agree with everything you reported, but want to load the GTS tables to make it stiffer. It floats too much IMHO. It's better, but could still improve I think. I just haven't had time to do this yet.

z3mcoupe

Bruce, your review mirrors my own impressions of the control box also. Finally, you can leave the dampers in firm on the road. I usually do unless I'm on a particularly bad stretch of road.

It is kind of amazing that the Porsche engineers didn't 'finish' this part of the suspension tuning - it should have certainly come this way from the factory. I also love how easy it is to install on the .2 cars, it's literally plug and play!

TheLex

Thanks Bruce for that detailed review. I too am annoyed with the "Bang" over freeway expansion joints. This one annoyance oftentimes causes me to grab the keys to one of my other cars whenever I head out for more than a short distance drive on the freeway. It's a fatiguing part of the 911 experience. I love the handling, the sounds, etc. I just hate the harshness over rough roads and the "bang". Looks like I'll be ordering this unit soon.

ADias

Bruce: How is braking? Please comment on (i) normal braking, (ii) trail braking and (iii) all-out braking with ABS intervention? Stability, mass transfer, traction?

Also... can you please comment on your perspective re to Wayne's reference to 'sky-hook' platform feeling. I suppose you know what it means, if not here are some references:

https://en.wikipedia.org/wiki/Active_suspension

http://www.prnewswire.com/news-relea...-55764957.html

https://www.researchgate.net/profile...uspensions.pdf

Petza914

Same impression as Bruce and I was one of the early adopters of the DSC. The problem with the OEM PASM suspension is that it lacks proper rebound dampening which gives you that wallowing back end feel. With DSC and my RSS motor mounts all of that is gone. Hruce you may want to get away from the OEM hydraulic mounts as they still allow for too much free weight transfer IMO.

I'd also take 15 mins t OK bolsters around with the g-tables and software programming as it's a shame for you to not have 2 usable modes in the box. Make your current Sport mode your Normal or soften it just a little and then create a slightly sportier sport mode for curvy mountain drives, parade laps, or what have you.

I have Bilstein coilover and full RSS suspension so I actually had to soften the Normal mode the DSC box came with and have it programmed to stay full soft up until about 40% as the Bilsteins take care of chassis control until then, but have them stiffen progressively after that so even in normal mode, high speed on ramps and evasive maneuvers stiffen things up instantly. This gives the car a very compliant highway ride for longer trips even with the track suspension. For my sport mode, I start stiffer even at 0% and progressively go to full firmness in even increments. This is my mountain carving, track day, and high speed highway setting. It's like having 2 different cars - it's that good.

For anyone with a similar setup in their 997.1, my maps are on the DSC share site and the file names describe the setting parameters.

Bruce In Philly

You are asking questions that go beyond my intent here... you are jumping deeply to the "make it better" and performance world and better is the problem. Better according to what standard?

Anywho.... I can say this: Besides fixing most of the what I consider the poor ride and handling for the 997.2, the DSC module keeps the performance high. And, given the tail doesn't hop and wag, it is better.

The Porsche system was active and reacted to braking, speed, and whatever else they wanted to react to. The DSC system keeps the ride compliant but also keeps the performance aspect of things.... that is what an active system is supposed to do and what Porsche did not do a great job of.

Regarding the hook aspect.... yes, the darn car seems to have more traction and stability in turns.... but I am only driving on the roads, not a track... Honestly, I have no idea if the DSC system extended the limits of the car or made it a better track timer.

Regardless of opinions, it sure seems to me that anyone considering modifying their suspension, regardless of the reason, should screw with the software first before swapping out hardware. It is just cheaper, easier, and highly configurable.

Peace
Bruce in Philly

ADias

I am sorry you see it that way. The first question is safety not performance and the reason I asked is that I know PASM and braking are interconnected, more so in a 911 than in any other architecture. The second question may have a performance answer even though my intention was feeling - because 'skyhook' changes the seat of the pants feel. Some like it, some don't.

voiceprint1

can I add my .2 cents, I gave a ride to friend in my non PASM base model and he was coming from a cayman with the PASM ect, and he commented that the ride was closer to a Cayman GTS in sport mode he drove recently.

I would love to hear from another C2 driver who has the base, do they experience what Bruce does? I find the ride in my car a bit rough, but passengers have described it as smooth?

Bruce In Philly

I have not tested braking at the extreme.... I just didn't do this test. The nose does not dive... but then it never dove (much). I just have not driven the car at the extremes on the roads so I don't have data. For the driving I did do, the car stays flat in Sport mode but can float over humps (not bumps) in Normal mode.

However, as soon as you put in a serious input such as brake, quick turn in, hard accelerate or pitch the car with a lateral G Force, the thing tightens right up and remains flat.

Regarding the "Skyhook" algorithms to ensure tire-to-road contact over uneven surface, I think DSC does this better than the Porsche tune. Again, I never pushed the car to slide so I don't have the science. I will assume that having a car lurch around will result in varied weight on the road and therefore changing friction coefficient witch, simply, cannot be good for traction. Note that in reading about skyhook algorithms, it is all about passenger comfort..... and the algorithms, as far as I can tell with my little brain, require tracking vertical movement of the car. The 997.2 does not have road height sensors on the wheels.... the 991s do have these sensors and DSC supposedly uses this information as input to the action it takes. Anywho... as I noted... the car runs flatter with the DSC software (at least feels flatter) than with the native Porsche algorithms.

Here is a good academic paper on Skyhook algorithms that you can download: https://www.researchgate.net/publica...ve_Suspensions

But regarding "seat of the pants", all I can say is the car is more comfortable, rides flatter, and feels more stable in turns and in particularly, bumpy turns. I purchased this software to fix a problem, not to do better trail braking or quicker lap time. Beyond this, I would be speculating way out my er .. um... seat of my pants.

Peace
Bruce in Philly