Bilstein and KW V3 are both excellent systems; both will transform the stock Turbo, which unfortunately in stock form is way too soft and as result becomes very boring after a few months of ownership for a number of people. If I didn't have Bilstein, KW V3 would be my choice, so why did I go with Bilstein?

1. Cost: In favor of Bilstein by a good amount. The key question is, does that extra chunk of money of KW buys you a "better" suspension, subjectively, or objectively? This is where it gets iffy.

2. Subjectively (which one feels better to drive): No evidence in favor of Bilstein or KW; owners of either are happy. That said, if you read between the lines and past complaints, it would seem that KW is a stiffer system. If you have a frequent female passenger, I would strongly suggest to stay with Bilstein.

3. Objectively (which one is faster to drive): No evidence to support one is faster than the other. At this level, if you are going to get track-serious, it's going to come down to the setup man and the driver, the tires, the spring rates, etc.. A better setup man and driver will make Bilstein faster than KW, and vice versa.

4. Ease of adjustment: For Bilstein, it's a big zero, no adjustment needed. The system is designed by the same team of engineers and consultant (Walter Rohrl) as the OEM suspension, so you know you *will* be in the right ball park. KW V3 requires tweaking of low speed/high speed bump and rebound dampening force, and that requires an experienced setup person **and** a very experienced driver to give the setup man feedback. Setting up low speed/high speed bump and rebound dampening is much more than going for the most comfortable setting (it actually affects understeer/oversteer behavior). It's black art best done by timing yourself at the track, etc., and the setup man is the key.

BTW if you want more adjustments, Bilstein also makes the non-PASM B16 PSS10 (vs. PASM B16 Damptronic), which allows you to set up to taste just like KW V3.
Also it's not true if indeed CEC said the Bilstein Damptronic has only 2 levels: Within each of the 2 levels, the PASM system's sensors continuously monitor the road condition, longitudinal/lateral acceleration, braking, steering angle, etc., and varies the dampening force accordingly. In other words there are multiple levels of dampening within each of the 2 levels. It is an incredibly sophisticated system and I was so very surprised to find out about the monitor/feedback system. BTW, the Damptronic's PASM system is much, much, much better executed than stock PASM, which has a design flaw (stiff is way too stiff and practically un-useable).

The bottom line is this: Lacking evidence that one is decidedly "better" than the others, either subjectively or objectively, cost and how the system feels become the deciding factor. Especially in your case, where there is a worry about the passenger, I would think Bilstein is the clear choice. BTW, my (humble) opinions and Bilstein recommendation apply to all who are first timers to suspension mods, and who want the car stiffer/tighter, but not too stiff for street driving. It's a very safe first start and it is extremely rare, practically unheard of, to find anyone who finds it so stiff that he wants to go back. It is really and truly a one way ticket to heaven LOL.

 

Ok. I gotta add to this thread with some some questions mostly related with bumpy roads.

No doubt when I go at a quicker pace on flat twisties the TechARTs work amazingly. However, I recently tried to DD the car (we have bumpy roads) and found the car to be very jittery and jumpy especially at slower speeds.

My question. Is this the result of a PASM system? My car has been stiffened up with sways and monoball suspension components vs. stock sways and rubber bushings. Could this jittery and jumpy be because of the computer programming of the PASM system - soft at slow speeds and harder as you pick up the pace? As a result, at slower speeds, my car will have a stiff chassis, body and monoball joints while running on a PASM computer modulated "softer" suspension setting.

Would this be improved with a non-PASM compatible suspension like the KW V3s? Means if I set up the KWs well and have a stiffer setting for both slow and faster speeds, would there be less jitter? Or is my jitter problem coming from the monoball components? One more thing I thought about is setting my sways from med-med to front-soft, rear-med. Would this soften the chassis a little (I don't mind having more oversteer) to reduce jitter.

Make sense? I'm totally guessing on this, so please forgive me if this is total BS.

Sorry, lots of questions. Trying to get the best of both worlds. Tight handing and less jump on flat and bumpy roads and while doing both fast and slow driving. Is it possible? Thanks!

 

First IMHO this is merely the classic trade-off between ride and handling. In general, as handling improves from stiffening of suspension, ride will suffer. You can't have both, and have to pick a middle ground that makes you happy in all conditions. Race car setup does NOT like bumpy roads and pro's readily alter suspension setup per road surface conditions.

1. No. In fact the PASM system allegedly does the opposite: it is supposed to soften up when road surface is bad, by reducing damping force.
PASM doesn't sense speed per se. What it senses is acceleration (longitudinal and lateral), road surface, braking, brake pedal pressure, steering angle, etc. Then it changes damping force to make car comfortable when it needs too, and stiff when it needs too.

2. Most definitely no. KW and Bilstein will have same behavior: stiffer suspension=more fun=less comfort. A properly setup KW (some apparently sent out with erroneously soft front spring??) have high spring rates (400/740) and might even be stiffer than what you have now.

3. Yes, most definitely these contribute to the overall stiffness. This is why in general, unless someone is a true track junkie, I recommend to change suspension in steps (so you know which step is causing problem- "one axle, one component at a time") and don't recommend altering the suspension links such as rear toe control arm, dog bones, etc.
Sorry, I don't mean to preach, above is for others new to this, not you.

4. Yes, most definitely so. In my experience with my particular setup (Bilstein with GMG sway bar and rear Tarett link), I have found the sway bar setting, in particular the stiff setting, has major influence on steering, handling, AND STIFFNESS. In fact I find the rear stiff setting to be unbearable.
For our Turbo, soft med is a "better" setting in general than med-med anyway. Less understeer and allows the front tires to "bite" better in high speed curves.

So bottom line: use soft tires such as Michelin PSS and make sure pressure is not over-inflated, change sway bar setting to soft med. The drop link also increases stiffness so that would be next to go. If that doesn't work, I would start taking out the other after-market links one at a time. Keep in mind though that your car will NOT be as much fun to drive in high-speed twisties.

 

Thanks Can. Makes total sense. Anyone know the exact difference between the Bilsteins and the TechARTs?

I'm gonna try changing the sway bar settings and look into the tire pressure.

I actually did do the suspension upgrade in steps. Funny thing is, every step definitely improved the car and ride comfort compromise was minimal; however, now I'm getting greedy and want everything.

This is a work in progress. Frustrating at times, but overall, an enjoyable learning experience. Thank you for your help.

 

You are very welcome. Re. Techart, we all know that it's a modified Bilstein Damptronic, but what is modified has never been revealed AFAIK. Some possibilities:
1. Same damper, stiffer springs.
2. Same springs, stiffer or re-valved damper. (Very unlikely.)
3. Same springs and damper, but revised ECU controlling the damper via PASM.

I am actually very curious to know. It would be fun and instructional for all if you could call Techart to find out, as a paying customer. They might be reluctant to tell but if you say something *inflammatory* like "some guy on the internet says Techart is just a re-branded Bilstein" then they might be more likely to spill the beans. Press and ask if they change the springs (stiffer front or rear, or both?), or the damper, or both.

Yes there is a "sweet spot" that you'll be very happy with and I am certain you have done enough to know what this spot is. For me the final fine tuning did involve setting of the sway bar and the drop link. Regarding tire pressure, as mentioned, they should be 33/39 hot with some small variations around this. Too much variation around 33/39 then one is using the tire pressure as adjustment for the suspension, which is not good because now yourare sacrificing tire traction, etc.

 

(1) is confirmed as the TechArts use Eibach springs.

As for (3), how would they revise the ECU? ECU Flash? Cause I have an FVD flash.

I agree that (2) is unlikely. So, I guess the main difference is (1) which could affect the ride of the car. Now I'm wondering what the difference is? Positive or negative? Hmmm . . .

 

By ECU I merely meant the Electronic Control Unit for the PASM. I have zero idea where it is and the extent that it could be modified. And I don't believe that it is in the physical space as the engine ECU. I mentioned that because a US tuner, TPC, has stated that they revise/modify the PASM ECU in their own version of the Bilstein Damptronic.

Yes springs that are different from Bilstein Damptronic original are a distinct possibility. If stiffer springs, in general you'll have better handling, worse ride. If softer springs, the reverse. The only way to know for sure is to call Techart and ask. It would be very interesting to know, and of course pertinent info for you.

 

I am picking up my car on monday with the KW v3 installed... the guys at the shop adjusted it 3X they are familiar with what I am looking for as far as my ride I probably will have to tune it from there. Regardless I will let you guys know hopefully I wont have to start adding more parts I want to get started on power mods.

 

There have been a couple of complaints about KW V3 that *seem* to be consistent with front springs that are too soft. I have no idea whether it's true for all the KW's (KW Germany and KW USA seem to be giving different info), and am curious what your tech has to say about this?

Note that you might "repair" this softness by increasing compression damping; but that's not necessarily the right way to do it. Better to change the spring itself, *if* indeed soft spring is the problem.

 

The ONLY KW suspension I'd ever put on a high dollar Porsche would be their Club Sport. The Varient (v3) stuff is low end product. For manually adjustable coil overs on a modern day Porsche the KW Club Sport, Ohlins, JRZ would be an improvement plus last a long time usually with out issues.

 

Anyone know if it is possible to just get the Bilstein Damptronic springs? If so, you guys think it's worth my time to try them on the TechArts?

 

Really? Is it that bad? Even for roads?

 

I just got my KW v3 on tested it for 2 days here are some comments.

quite bouncy at low speeds but not comparable to how bad it was on sport plus with stock suspension.

At highway speeds its actually alot smoother with the KW.

In turns the car is just amazing, I have full control... I did a quick slide in a turn with full confidence the car almost feels like it lost all electronic stability and became amazingly mechanical I really can feel everything. I could see how this set up is perfect for track... I mainly street race and DD therefore if I could do it again Id go bilstein but I have very happy with this product mainly for it's handling in the corners at fairly high speeds something I did not feel comfortable with before.

Bodyroll is completely gone.

 

Alexo, congrats.

For anyone new to the Turbo, however you want to skin the cat, Bilstein, KW V3, or stiffer lowering springs such as GMG or Techart, a change to stiffer springs is indeed **THE** most significant and satisfying mod for our Turbo, IMHO. For a number of people the stock Turbo is simply tuned to be too soft, too mushy.

While I love my Cargraphic exhaust and the GIAC ECU tune and wouldn't want to be without them, if I could only pick one "most significant mod", it would be the Bilstein, hands down.

 

Congrats on the V3s. I think they are a perfect setup for the street and occasional track day. I've had them on 3 cars and love them! Even on 20's the ride is way better than stock wheels.