Tom@TPC Racing

OP-

First make sure the tires are in good shape(at least 50% thread, and no age cracks). Once verified the tires are good then consider our suspension control module to replace the factory PASM module,for this generation of 997 the factory PASM is a bit lacking as it was Porsche's first gen PASM. Our control module is called DSC(Dynamic Suspension Control), there are hundreds of DSC users reported faster lap times on track while improving high performance driving stability and enjoyment and comfort. Our DSC technology is so superior that even car owners with 991 GT3, 991 Turbo, and GT4 are installing them with no regret. If you install the DSC which we also use GT3 mapping, then do a factory spec GT3 alignment the car will handle awesome. 2008 car will require DSC 3-axis accelerometer because the care came factory equipped with 2-axis. 2009-newer cars came with 3-axis.

Regards,
Tom

evo9

Hello all:

I have a 2010 c2s 6m w/ pasm w/ 40K miles. And, I'm glad to see other folks have/are experiencing similar rear end "wag" that I have observed in my car. At least I now know nothing is busted. suspension-wise in my ride. More specifically for me, when executing a fast highway speed lane change (70-80mph) while accelerating (moderate to heavy on the throttle), rear end exhibits what I would call a slight oscillation/weave. Seems to occur regardless of pasm selection. A little disconcerting to say the least because I know your not suppose 'to lift' off the throttle, which would lighten the rear and most likely make it worse, especially if in a turn. In steady state high speed curve, car is fairly stable but, if there is a mid-corner dip or bump, I get what seems like an extra 'rear-end bounce'/oscillation. It seems to my novice senses, like a lack of rear shock rebound dampening.

In any case, based on forum members favorable feedback of TPC DSC module, it seems like that may be my first suspension related mod., to address this rear-end wag/weave/oscillation/yaw I've experienced.

Cheers,

Wm

Mike Murphy

Bruce In Philly

Check to see if your rear shocks were leaking. Mine did and I had a similar experience (2009 C2S) but I had way more miles on the car.

Read some here: https://rennlist.com/forums/997-foru...ecs-oh-my.html

Peace
Bruce in Philly

kmetros

I have a new set of Michelin Pilot Super Sports and an alignment scheduled for later this week. Plus, a DSC module is on the way! The DSC module is the one I'm really excited about!!

exgtinows4

i had issues with my GTS with the unsettled rear end, mostly during hard braking. I eventually got rid of it with upgrading to mono ball dog bones in the rear and toe holding rear links. These upgrades really really helped. That and a good track alignment.

Of course goes without saying that you should rule out obvious issues first like others have pointed out...

MaximumA

I'd check your tyres, typre pressure, alignment, and then suspension parts. The only time my car's *** wags is when I'm overdriving it, or it's winter. And then, it's only a little wriggle.

Mike Murphy

jchapura

What does it mean/how to check suspension parts?

I have a 2005 C2S ~75000 miles. 4000-mile-old Michelin PS4Ss. 8000-mile-old Function First semi-semi-solid v2 engine mounts.
12000-mile-old alignment is "milder" to combat the rear inner edge tire wear normally seen.
Shocks are dry - no apparent leaking.
I get tail wag/wallow whether in Sport or Normal mode.
My "control" ramp brings the wag out every time - 70 mph constant throttle right-hand sweeper, slightly reducing radius, small wave/bump in road leading to a jostle and the wag/wallow.
Other road defects/car conditions produce a similar wag/wallow.

I've put the car up on my QuickJacks.
I've visually inspected the rubber bits I can see from underneath.
I pulled and pushed on suspension parts.
I've used a 6ft 2x4 pry bar to try to see untoward deflection.
I'm just not seeing anything.
If I did see deflection - how much is too much?
What am I doing wrong in trying to inspect the suspension to find a part that needs to be replaced?



Front - no change (other than to vertically-align steering wheel):
Rim diameter: 20.5 in or 520.7 mm
Start and finish:
Toe L 1 mm in or 0.22 deg in
Toe R 1 mm in or 0.22 deg in
Castor L not measured
Castor R not measured
Camber L -0.8
Camber R -0.7

Rear:
Rim diameter: 20.5 in or 520.7 mm
Start:
Toe L 2 mm in or 0.44 deg in
Toe R 2 mm in or 0.44 deg in
Camber L -2.0
Camber R -2.0
Finish:
Toe L 1 mm in or 0.22 deg in (spec is 0.08 deg in to 0.25 deg in)

Bruce In Philly

Good question.

I my experience, these cars are so tight, it is hard to really see anything wrong unless it is really wrong. You will hear/feel clunks way before they are visible such as destroyed bushings. About the only thing you can readily see are leaking shocks. This happened to me .... just the rears.

With less tight cars, you sometimes can take a crow bar and apply pressure... if you see a joint moving, then it is bad, but these cars are so tight, that really doesn't work that well.... maybe if you are an expert on them. There are common wear points, should you just want to replace stuff, such as the lower control arm... the one with three attach points, one being in the center.

Just check for uneven or odd wear on your tires and look for shock leaks.... listen for clunks that occur when driving slowly over undulations (not bumps). That is about it IMO.

Peace
Bruce in Philly

jchapura

kmetros, did you ever get this diagnosed before putting on any new parts (besides tires)?
If you did put new parts on, which ones and do you think it solved the problem?
Thanks!

wc11

You've gone from a front weight biased car to a rear wight biased car.
So much more fun to drive but you must be mindful which reminded me of a question on curves...