cstyles

I can report that when the DSC is paired with Eibach springs on oem PASM shocks, the results are exceptionally good - street and track. @4ocious, maybe you could look at replacing whatever springs are on your car with a more compliant set of springs without such an aggressive drop ie Eibach. The 997.2TT has an upgraded OEM suspension system over then 997.1TT, so for you to have such poor ride quality there must be a specific reason ie ****ty springs. Based on your pics and how low your car is, I bet they are H&R.

4ocious

Thanks everyone for your comments. My TTS does sit lower than other P-cars. That's the first thing I noticed when I bought it 9 months ago. But, I don't have a lot of seat time in it so I initially dismissed the ride quality. Several months ago I drove to North Carolina and upon my return I felt like I needed to visit a chiropractor. Granted I-95 in the mid-Atlantic states isn't the best in some areas but overall t's not too bad so I was surprised by the uncomfortable ride quality. That was my first real clue but my TTS has been garaged since then because of weather and only occasionally street driven. I was hoping the DSC would make a difference.

Anyway, my next step is to visit a suspension shop and baseline what my current set-up consists of (H&R, Eibach or other springs, non-OEM PASM shocks, suspension mods etc.). I will also experiment with different inflation pressures and if necessary purchase new Michelin PS4's earlier than expected because I don't like my Bridgestone N2's. If these mitigations fail then it's time for Plan B which is - ?

DocHW

John NY-Naples

Maybe go back to the stock suspension/springs and see how you like it? Then decide on the DSC. I have the stock suspension on my 997.1 TT, and I'm perfectly fine with it in either normal or sport mode. I don't track my car, so my needs may not be as demanding as others, but the normal mode feels like perfect balance between comfort and road feel, while the sport setting gives you the harsher ride one would expect.

Tom@TPC Racing

What is your ride height measured from the ground to the middle of the fender?
The lowest we would set the ride height on a 997 road car is 25.7" front / 26.4" rear.
Our typical target for a 997 road & track car is 26.0" front / 26.6" or 26.7" rear.
For reference stock height is around 27.0" front / 28.0" rear.
When the ride height is too low, the shocks are either too close to bottoming on the bump rubber or already riding on the bump rubber. If this is the case, then DSC isn't going to help since there's no suspension travel except suspended on the rubber.
As others have mentioned, please take a photo of the springs and show us. We can try to determine by photo if the springs are too stiff for the shocks to the effective. If this is the case, then DSC isn't going to help either since the function of DSC is to control the travel movement of the shocks, when the spring force is greater than the shock's mechanical capability, the shocks are then just along for the ride.
DSC works great when there's enough travel range of the shocks for it command, and when the springs aren't stiffer than the shock's mechanical capability.
I don't think there'll be a huge change in comfort switching tires. Before buying new tires you could drop tire pressure by 5psi and drive around a low speeds just to get a feel. Dropping 5psi will make any tire ride less harsh. Just don't go below 30psi cold. They need minimum of 30psi to support the weight of the car.
Does the car feel bouncy over bumps or just plain harsh jarring over bumps?

4ocious

Hi Tom,

Thank you for the information you provided above. Both fronts measure 26.7" and the rears are 27.3" cold inflation, flat surface at recommended pressures.
But, I did take a much closer look at the front springs. Both have three coils but the drivers side front appears bent and it's partially out of its cradle.
I can only assume that makes a huge difference?

Tom@TPC Racing

Your ride height of 26.7" / 27.3" sounds good.
What tire sizes are you using? The ride height numbers I provided are for stock size tires.


That does not sound good. You should have an experienced professional mechanic inspect the bent spring coming out of the cradle.

JG 996T

That cannot be good.

4ocious

After work yesterday I took the car to a reputable indie who specializes in European cars. We put it on a lift and looked at the springs and shocks. My springs appear to be stock OEM two coil and are not painted like Eibachs or H&R's. The shocks also appear to be OEM without any leaks. Per your recommendation we also checked the front sensor connections which appear to be ok.

The mechanic said the springs are connected correctly and not bent or overly compressed on the drivers side. He showed me where it's normal for the bottom coil to spiral upward out of its cradle to form the middle coil. And spiral downward as it forms the bottom coil. We also looked at the passenger side which is doing the same thing. I want to believe this is correct but is it?

I'm not receiving any PASM failure lights and I did switch from normal to sport several time which operated correctly although I really couldn't tell the difference between the two. You asked how the ride is when I hit a bump?. I feel all bumps because the suspension bottoms out vs. float over them.

Anyway, "I think" perhaps what I'm experiencing is normal and I'm just not use to it. But, I just looked for springs for my TTS on Ebay. The Eibach's and H&R's all have four coils not two. Is it possible the former owner cut the OEM springs? What do you think?

Rambler_13

4ocious, was the tech able to comment on whether maybe the suspension is worn and in need of replacement? I'm not aware of whether the S suspension is any firmer or different than the non-S but I've never felt mine to be too jarring or uncomfortable in any way. Even sport mode is very tolerable on decent roads. Our roads here are pretty terrible too.

JG 996T

The picture of the yellow car in your avatar is not stock ride height. Might have cut the springs.

I have gmg. Not yet installed, but it looks like at least 5 coils.

4ocious

Thank you, my springs don't look at all like that! The top connector doesn't count as I understand it. So, when looking at mine I have a middle coil and a second coil that ends in a cradle. I suspect my OEM springs have been cut. They center coil has a blue rectangular square and a white rectangular square but they are otherwise unpainted.

I think it's time to replace the springs all around. I don't want to lower the car any lower than it is so maybe it's time for spring recommendations?

Kayaknfly

Can you post pics of your springs? I'm curious as to what they look like.

4ocious

Can you post pics of your springs? I'm curious as to what they look like.[/QUOTE]

4ocious

Attached above are photos of my springs, The top is the passenger side and the bottom is the drivers side.