"Foating" feeling with PASM
#1
"Foating" feeling with PASM
Hey all,
I have a 2009 C4S that I purchased about 9 months ago. The car has an interesting feeling to me when PASM is in Normal mode that I would describe as "floating." The suspension still passes through bumps and feedback to the chassis and steering, but there's a hard to identify quality that reminds me of the chassis being a little disconnected from the suspension. If I put PASM in Sport mode the feeling goes away, but then the ride is too harsh for every day commuting. In normal mode, I would also describe the steering as "too easy," i.e. there's not as much weight to the steering as I would expect at high speeds (70mph+). This all combines to make the car feel less rock solid than I would like when I'm doing 70mph+ in the middle lane of crowded highway.
This is all very subtle, so it could be totally normal. But I don't have any other 997s available to compare mine to so I can't say for sure. Anyone else ever feel anything like this? Is this just tramlining in action? Do I need new shocks? The tires are only a few thousand miles old (Bridgestone Pole Positions), which I put on because the previous owner had Pilot Super Sports, and one of the rears wasn't round, which caused the whole car to vibrate slightly at high speed. The new tires have a nice smooth, quiet ride, so I don't think it's the tires, but I guess anything's possible. Thoughts?
Thanks!
I have a 2009 C4S that I purchased about 9 months ago. The car has an interesting feeling to me when PASM is in Normal mode that I would describe as "floating." The suspension still passes through bumps and feedback to the chassis and steering, but there's a hard to identify quality that reminds me of the chassis being a little disconnected from the suspension. If I put PASM in Sport mode the feeling goes away, but then the ride is too harsh for every day commuting. In normal mode, I would also describe the steering as "too easy," i.e. there's not as much weight to the steering as I would expect at high speeds (70mph+). This all combines to make the car feel less rock solid than I would like when I'm doing 70mph+ in the middle lane of crowded highway.
This is all very subtle, so it could be totally normal. But I don't have any other 997s available to compare mine to so I can't say for sure. Anyone else ever feel anything like this? Is this just tramlining in action? Do I need new shocks? The tires are only a few thousand miles old (Bridgestone Pole Positions), which I put on because the previous owner had Pilot Super Sports, and one of the rears wasn't round, which caused the whole car to vibrate slightly at high speed. The new tires have a nice smooth, quiet ride, so I don't think it's the tires, but I guess anything's possible. Thoughts?
Thanks!
#2
Rennlist Member
When was the last time you had an alignment done ? The light steering feeling at speed could be helped with a bit more toe-in. I run +0.04 front toe and +0.10 rear, this is stable at speed. I used to have +0.00 front toe when I felt the steering was light at speed.
#3
RL Community Team
Rennlist Member
Rennlist Member
2009 C2S 111k miles
I was getting that also... My rear shocks we're leaking. Pull the wheel and look, you can easily tell. I went and replaced all four shocks and issue stopped.
Driving on the Jersey turnpike, I would odd bobbing, kinda made me nautious.
See my post on this issue here: https://rennlist.com/forums/997-foru...ecs-oh-my.html
Peace
Bruce in Philly
I was getting that also... My rear shocks we're leaking. Pull the wheel and look, you can easily tell. I went and replaced all four shocks and issue stopped.
Driving on the Jersey turnpike, I would odd bobbing, kinda made me nautious.
See my post on this issue here: https://rennlist.com/forums/997-foru...ecs-oh-my.html
Peace
Bruce in Philly
Last edited by Bruce In Philly; 04-24-2017 at 05:41 PM.
#4
If you shock are OK, look into installing DSC PASM control box. My 2012 997.2S with 18K miles also had the floating you described. Installed the DCS box and the car handles amazing. $1200 but worth every penny. DSCsport.com
#6
Rennlist Member
I think I know what you mean, I have a 997.1 and a 997.2 and both exhibit it, so for it to have 8 pieces of suspension fail in the exact same way is not probable. More likely is that the stock PASM setting is too soft with LTA rebound and the Sport is too stiff. I have the DSC on the 997.2 (had in on the 997.1) and that is the answer to the floatiness!!! Of course that is pending that all your hardware is in good working order.
#7
It could be all the above issues, but let's not forget the engine is out back. I think for the overwhelming majority of us, we came from front-engined cars (and front more so than rear-wheel drive probably). And now it's AWD with the engine not just "outback" but rear-engined as well.
(And not a knock on anyone's driving ability!)
(And not a knock on anyone's driving ability!)
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#9
Not sure if this is of any help, but I felt (and still feel) a huge difference from my old 02 996 C4S compared to my "new" 09 997.2 C4S
When I have PASM set to Normal Mode it feels so much softer and nicer to drive on a day to day basis and when I switch to sports mode it becomes so much firmer (pretty close to my old 996 feel).
Now, this may sound strange to most of you but I suffer from migraine, and had a tendency to get headaches when driving for prolonged times in my old 996 which has totally disappeared after I got my 997.2 with the PASM set to normal 95% of the time. When I have the PASM set to sport my headaches actually returns much faster... Maybe it's all in my head (well the actual headache kind of gives it away here) but I really do think the PASM in normal is fantastic and should be as soft as it is...
When I have PASM set to Normal Mode it feels so much softer and nicer to drive on a day to day basis and when I switch to sports mode it becomes so much firmer (pretty close to my old 996 feel).
Now, this may sound strange to most of you but I suffer from migraine, and had a tendency to get headaches when driving for prolonged times in my old 996 which has totally disappeared after I got my 997.2 with the PASM set to normal 95% of the time. When I have the PASM set to sport my headaches actually returns much faster... Maybe it's all in my head (well the actual headache kind of gives it away here) but I really do think the PASM in normal is fantastic and should be as soft as it is...
#10
Not sure if this is of any help, but I felt (and still feel) a huge difference from my old 02 996 C4S compared to my "new" 09 997.2 C4S
When I have PASM set to Normal Mode it feels so much softer and nicer to drive on a day to day basis and when I switch to sports mode it becomes so much firmer (pretty close to my old 996 feel).
Now, this may sound strange to most of you but I suffer from migraine, and had a tendency to get headaches when driving for prolonged times in my old 996 which has totally disappeared after I got my 997.2 with the PASM set to normal 95% of the time. When I have the PASM set to sport my headaches actually returns much faster... Maybe it's all in my head (well the actual headache kind of gives it away here) but I really do think the PASM in normal is fantastic and should be as soft as it is...
When I have PASM set to Normal Mode it feels so much softer and nicer to drive on a day to day basis and when I switch to sports mode it becomes so much firmer (pretty close to my old 996 feel).
Now, this may sound strange to most of you but I suffer from migraine, and had a tendency to get headaches when driving for prolonged times in my old 996 which has totally disappeared after I got my 997.2 with the PASM set to normal 95% of the time. When I have the PASM set to sport my headaches actually returns much faster... Maybe it's all in my head (well the actual headache kind of gives it away here) but I really do think the PASM in normal is fantastic and should be as soft as it is...
I also suffer from migraine on long driving trips!!
#11
I would go with this. Mine was floaty when I first bought it as it had a very aggressive, track-focused alignment.
Realigned to a more tire friendly street setup and it's solid and still handles far better than I'm willing to push on the street.
Realigned to a more tire friendly street setup and it's solid and still handles far better than I'm willing to push on the street.
#12
Instructor
I agree that the PASM is a bit too soft and floaty in normal mode, but the fix is probably to spend the money on the TPC DSC module. Or to swap out the DampTronics for some new and more focussed coilovers.
#13
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The floaty characteristic on 997.1 and 997.2 cars is from insufficient shock damping force to counter the road forces. Assuming the shocks aren't broken or leaking or worn out, DSC adds compression damping force to gain control of the downward movement and the adds rebound damping force to clam the suspension's recoil and oscillation. These DSC functions make the car more stable and provides the driver with good feel of the front end to improve the driving experience. If there's no broken or worn out suspension part, DSC + sport alignment = fantastic street car.
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PCA National Instructor
TPC Racing stats:
2023 Porsche Sprint Challenge 992 Cup Am Champion
2023 Porsche Sprint Challenge GT4 Pro-Am Team Champion
2022 Porsche Sprint Challenge 992 Cup & 991 Cup Champion
2020 IMSA GT3 Cup Challenge 2nd Championship
2018 IMSA GT3 Cup Challenge 2nd Championship
2016 IMSA GT3 Cup Challenge Champion
2013 IMSA GT3 Cup Challenge Champion
2006 Rolex-24 @ Daytona GT Champion
2004 Grand-Am SGS Class Champion
#14
Three Wheelin'
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I don't think there is anything wrong with the car.
The PASM in std setting (off) is very soft in dampening. Quick bursts of acceleration will not give it enough time to react. However - if you continue to drive really hard for extended period it will stiffen up substantially.
The two PASM settings are actually overlapping slightly. So - theoretically you can get the same effect (equivalent to PASMon) just by driving consistently hard with PASM off.
I always activate it if I know I will push the car as I don't like the swaying if the road is a bit bad.
The PASM in std setting (off) is very soft in dampening. Quick bursts of acceleration will not give it enough time to react. However - if you continue to drive really hard for extended period it will stiffen up substantially.
The two PASM settings are actually overlapping slightly. So - theoretically you can get the same effect (equivalent to PASMon) just by driving consistently hard with PASM off.
I always activate it if I know I will push the car as I don't like the swaying if the road is a bit bad.