L_perm

Ever driven an old patch of interstate at 75 mph and wondered how your car, your wheels, and your back are still in one piece afterwards?

I don't know what to do about my suspension.

I like to drive long distances, and I often travel from Charlotte to DC and back. When I can, I go VA back roads, but that doesn't always work with my schedule.

I have driven that route (I-85 to I-95) with the car bone stock. I've driven it with: Ohlins R&T coilovers (14 clicks out), Ground Control camber plates in front, RSS toe links, RSS dog bones, GMG sways, and Tarret drop links. I then softened the coilovers to 18-clicks out and drove the route. I then softened them all the way (about 22 clicks out) and removed everything else but the sways and drove the route. (The coilovers have always been set to minimum drop, which amounts to about a half inch.)

I still can't relax and drive because I have to brace myself for the next road-to-bridge expansion joint that slams me around as if I'm in a wooden wagon!

Is there no way to make the 997.1 Turbo not bounce like a boat (stock) without sacrificing your back???

Observations:
- I loved the effect of putting everything on until I took a long trip up the interstate--more noise, tiring over the filled potholes and road imperfections, and the big road transitions WILL hurt you if you are not seated correctly.

- Taking the links out reduced the NVH-type noise, but I'm thinking of putting them back, because the handling is noticeably degraded without the links, even with the coilovers and sways still on.

- The sways are either coming off, or the bushings will be changed to rubber, because the urethane bushings are noisy--creak, creeaak, creak, creak...

- My rears will not go less than -1.4* camber with the eccentric. It was with the dog bones and toe links that I had the rears set at -1.0* camber, and the car felt better through a curve then than it has since. (I had -1.4* in the front then, and still do.)

- To me, the stock PASM setup was too soft (bouncy) in "Normal" mode and way too stiff for use on any public road I know of in "Sport" mode.

Options?
- Do I go softer on the Ohlins coilover springs? Can it be done without causing a shock/spring mis-match?

- Is there an OE-style strut/spring alternative that is better than stock? Or, do I only have lowering springs or coilovers to choose from? (My experience looking at just springs was that all of them were meant to lower the car and were stiffer than I really need them to be.) There is seemingly no alternative that is meant to improve upon the stock setup without the track in mind--no in-between.

- I know of the TPC PASM Module, but is it meant to help with interstate expansion joints, so to speak? I can't tell from the chatter whether they make a significant improvement on the stock "Normal" PASM mode. It seems meant to improve track performance, and I don't know how that translates to my issues.

LP

Terry Adams

Agree.

Have done I-95 11 hours to FL, and have done partly the back roads. Just on OEM.

I call it "In your tail pipe at 95 (mph)" the way they love to tailgate a Porsche.

Can't suggest an alternative.

Newer tires help a lot but that's not a valid suspension solution.

nzskater

Buy a Macan, and save the Turbo for the weekend?

XPC5

18" wheels with more tire sidewall to absorb some of the impacts could help. Tire brand/model also is a factor, check reviews/tests as some are more absorbent of impacts and noise reduction than others (eg. michelin pss is very smooth and quiet in that regard). You could reduce spring rate on the ohlins, that will help. For best ride and bump/pothole absorption I would stick with stock sways.

So recipe is:
Ohlins, - and fine tune with spring rates and shock settings - stiffer than stock though and you get ride height adjustment
No camber plates - the spherical bearings add harshness
Stock sways and links - will reduce one wheel bump harshness
Taller profile tires on 18" wheels

TT Surgeon

Bilstein b8s with lowering springs of your choice or b6 with stock springs coupled with a dsc box. Stock gt2 rear bar only, no additional links, etc.

L_perm

Same experience--everyone wanting to push that Turbo. Tires are new PSS. I could probably reduce the pressures a bit more.


I have a 2013 Cayenne GTS, but it's not as fun as the Turbo. The Cayenne makes the trip very nicely, though.


I have new 19" PSS's on right now, so I don't think it is tire brand. I agree on the 18" suggestion. I'm not sure how feasible it is, given how much I have in my 19" wheels, but I'll look into it. The sways will be coming out, though I honestly don't think they are significantly related to my main issues. I have the GMG's set to their softest settings, which I believe were only around 15-25% stiffer than stock.


I'll ask TPC about the Bilsteins when I call them about the DSC box. How stiff is the rear GT2 bar? Maybe I can approximate it with the adjustable GMG.


Thanks for all the replies,
Louis

TT Surgeon

The gt2 is similar to the gmg bar but with rubber bushings.

L_perm

Thanks. As I mentioned, whatever bars end up on the car, the bushings will be rubber, not urethane. Looks like leaving the GMG in the rear with new rubber bushings and putting the OE front back on may be my next move where the sways are concerned.

I'm going to call the regional Ohlins supplier and discuss spring options, and I'm also going to call TPC.

Just BTW, the Ohlins springs are 400/686 inch pounds f/r.

TT Surgeon

Switching the front out is a big job, maybe just swap rubber bushings and leave the bar. When I had gmg springs, dog bones, links and f/ r sways on my first turbo it wasn't all that bad. When I added coil overs and drop links it sucked. The coil overs might be the culprit.

L_perm

I agree. I think I'm going to have the dog bones and toe links re-installed. They do transmit noise, but I don't think they are a major part of the "bump comfort" story. And, I did like their effect on handling.

I have Eibach coilover springs coming for the Ohlins. I went down to 300/550 lbs/in f/r from the Ohlins' stock 400/686. I talked to Ohlins and they told me I could soften by up to about 30% without having to re-valve.

I also have rubber bushings on the way from GMG.

L_perm

Correction: GMG didn't have any rubber bushings, and I couldn't find any that I knew would fit the GMG bars. So, I've got a GT2/GT3 rear bar coming that I will have installed along with the stock front.

The Tarret drop links will not be going back on, but I am going to re-install the RSS dog bones and toe links. The softer Ohlins springs 300/550 will also go on. So, I'll have rubber all around, except for the dog bones and toe links, along with softer springs that do not require a re-valve of the shocks.

I'm contemplating whether I should have the Ground Control camber plates up front removed. Can't decide.

bondjockey

Think about installing GT3 lower control arms instead of the camber plates. You can dial in a fair amount of neg camber with less nvh. My set up is pretty similar to yours now -- stock front bar, GT2 rear bar, Tarret rear toe links and locking plate, stock springs and struts, front GT3 LCA's, TPC DSC and an aggressive alignment. It handles really well and won't shake out your molars. If I don't complain on the twisties and my wife doesn't complain going over bumps I know I got it right

L_perm

How does the GT3 lower control arm differ from the Turbo's? Is it adjustable but retains the rubber bushings?

I only run about -1.5* of camber up front. Do I really need anything other than the stock parts? I was initially of the understanding that I needed the camber plates to accommodate the coilovers, but someone recommended removing them.

My wife won't ride with me. She hates sitting so low--has motion issues. So, this is all about ME!

LP

bondjockey

Ha! The stock Turbo LCA only allows for something like -0.6 of neg camber. The GT3 LCA allows for more neg camber but if you want to go above -2.5 you need camber plates. I am running -1.9 in the front with a 10mm shim. Tarret sells the kits w/choice of bushings (I got rubber). It basically allows for more aggressive alignment and better handling w/out a harsh ride.

Kevin at UMW suggested this set up and everyone knows he is the man!

L_perm

I'll look into it. Thanks!