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Rough ride
- Thread starter Union Pacifik
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- Driving Dynamics Model S
mspohr
Well-Known Member
A working hypothesis is that there is some combination of suspension hardware or assembly procedures which is causing a rough ride. Alternatively, this is all in the heads of the owners. I believe the latter is less likely since as you point out, most people are reasonable and knowledgeable. That's why I think it's important to have some data. Lots of random anecdotal reports don't really give us any good information (the plural of anecdote is not data).
mspohr
Well-Known Member
It would be good to have a recording when you feel the rough ride to compare with a recording when the ride feels OK.
I assume the recordings you posted are during the ride feeling "OK".
I'm in Carbondale. Its snowing a lot, the SC tech was supposed to come up last Friday from Denver but snowed out.... What is the name of your tech?
Joe F
Disruption is hard.
That's disheartening...
The suction cup I planned on using to mount the phone and take VibSensor measurements with has too much "play" so I just ordered a Seasucker mount with 2 day shipping. Also planned on attaching an ipad on the passenger seat to record audio and video.
I'm in Morrison and yes, I use the (one and only) Colorado Service Center on Evans. I was just there on Saturday because of a TPMS/tire issue I've had since the day I took delivery. Wouldn't you know it, I have had my CR-V for 20 years and never had a flat or leak and it looks like I've had a nail in one of my Model S tires since delivery day. Of course it was unrepairable and required a new tire.
BTW, we took a couple rides on C470 and Rooney Road by Bandimere yesterday and recorded the results. It will be interesting to see if there's a difference between coils and air.
Another data point for air rough riders. This is probably getting into the realm of crazy talk but, one thing I've noticed is that, if I go at least a week without the air suspension having to add air (ie, no other passengers or loads or raise to high/very high), the suspension seems to smooth out a bit. If I add air by adding passengers/load or setting high/very high setting, once I get back to standard height with no load, the ride quality sucks again. I wonder if there is a difference in spring rate for air bags filled with fresh air vs week-old air. I think I'll use one of the accelerometer apps to test this theory..
mspohr
Well-Known Member
Well, the air does get worn out with all that compressing and decompressing so you probably have "tired air" after a week.
Yikes!
This saddens me greatly. I was hoping they could just replace the shocks or something.
I feel as though my car has no shocks at all. It just bangs with even the tiniest crack in the road. A true bump? Forgettaboutit.
The problem is that the ride gives me a literal headache
It's like bang bang bounce BAM! Bang bounce BAM! Bounce.
My plan is to have them drive the car for a week while I'm in Maui and try to figure out ANY way to soften the ride.
If they can't I might sell and buy an inventory model AFTER driving it to work and back.
Weird to sell a car with 500 miles on it but...
Joe F
Disruption is hard.
While I feel the same, with a little over 200 miles, don't throw in the towel yet. That was only one attempt by one SC, at least as reported here, and as such isn't definitive enough to say it's a "feature" and not a problem. At least that's how I'm feeling at this point...
Enjoy Maui! Hopefully your SC will figure it out. I still have my Infiniti, and might have to do the same and tell them to call me when they've solved this very real problem.
Joe F
Disruption is hard.
Recd the SeaSucker RAM X-Holder mount. Should call it BIG Sucker! Will not get a chance before the weekend to test with VibSensor,
HOWEVER...
Don't know if it's related or not, but had to do a short drive on a street I hadn't had the Tesla on yet yesterday. In some stretches there are some washboard ripples and a few dips near storm drains. Thought my head was going to explode!
I remembered reading old threads on TMC on pressure buffeting, and how to solve it, but filed it away and promptly forgot about it. Until yesterday. I mean, it shook the whole car, or at least felt as if it did. Don't know if the rear hatch "flapping" is enough to cause resonate movement in the entire car or not, I highly doubt it, but am leaning towards that possibility...
Today I checked both the frunk and truck adjusters, and the two adjusters halfway up the rear hatch were not even close to touching their mating surfaces. It took over two full revolutions to start to touch. All other adjusters were okay, including the two large adjusters in the frunk, even after the little slip of a lady who ran thru the features of the car at delivery cranked them in a few turns after she couldn't manage to close the frunk, and asked me to fully close it.
Will get a chance tomorrow to run over the same stretch of road to see if at least the BOOMING body punishing pressure waves are gone, and if that played any part in the harsh ride, which again, I highly doubt.
-Joe
HOWEVER...
Don't know if it's related or not, but had to do a short drive on a street I hadn't had the Tesla on yet yesterday. In some stretches there are some washboard ripples and a few dips near storm drains. Thought my head was going to explode!
I remembered reading old threads on TMC on pressure buffeting, and how to solve it, but filed it away and promptly forgot about it. Until yesterday. I mean, it shook the whole car, or at least felt as if it did. Don't know if the rear hatch "flapping" is enough to cause resonate movement in the entire car or not, I highly doubt it, but am leaning towards that possibility...
Today I checked both the frunk and truck adjusters, and the two adjusters halfway up the rear hatch were not even close to touching their mating surfaces. It took over two full revolutions to start to touch. All other adjusters were okay, including the two large adjusters in the frunk, even after the little slip of a lady who ran thru the features of the car at delivery cranked them in a few turns after she couldn't manage to close the frunk, and asked me to fully close it.
Will get a chance tomorrow to run over the same stretch of road to see if at least the BOOMING body punishing pressure waves are gone, and if that played any part in the harsh ride, which again, I highly doubt.
-Joe
Joe F
Disruption is hard.
Great job on the comparisons Erik. Although it doesn't illustrate the problem some of us are having. I agree with jmsurpi.
I should have a good idea tomorrow if my "fix" solved it for me at least.
I should have a good idea tomorrow if my "fix" solved it for me at least.
I have a dialogue open with Jeffrey Sternisha. [email protected]. I've told him what I'm experiencing and I've sent quotes from this thread showing all the similar complaints. I've also mentioned that there are at least two other people on this thread from Colorado with the same problem as I. Jeff is not a tech, he's a delivery orientation specialist. I've got an appointment with the tech on 1/24/17, but I don't know who it will be with yet. I might move the appointment up, if my winter tires come in earlier.
I've taken measurements using the iphone's accelerometer. Will post pics once I download from my phone, but here is the gist of it:
(1) My Tesla (19inch GY, coil, 60D) Vs. Wife's X5 on moderately bumpy road:
Graph shows about twice as much force on my car vs. hers. The feeling was laughably large though - the graph doesn't do it justice. It's not even close in terms of feel.
(2) My Telsa Vs. Coil Demo (19inch GY, 75D) at mall on smooth highway (Hwy 25)
The graphs look similar, but the cars still feel very different. The demo felt fine where mine still felt rough. The demo did feel a little bouncy, but it absorbed the initial shock like a normal car. My cabin jumps on even the slightest bump. In some cases, it felt like my car was almost getting airborne.
(3) My Tesla Vs. Coil Demo on smooth suburban 35 mph road
Graphs look the same. Feeling were similar to highway - mine felt rough, demo felt fine. Not much bounce on either though.
(4) My Tesla Vs Air Demo (21 inch GY, 85D) on highway 25
Again, graphs looked similar. Air felt much better in all respects than mine. It absorbed bumps and had no subsequent bounces.
It was clearly the best of the three. The demo coil was in the middle.
(5) My Tesla Vs Air Demo on smooth suburban 35mph road.
Same as #4.
I could not test the air demo or coil demo on the same bumpy road I tested the X5. It was too far away. The only road I could find were smooth.
My car was set to exactly 45 psi cold. The other cars were not indicating low pressure, so they must have been at least 40psi.
My wife's car was set to exactly door spec (46 psi back, 37 psi front)
Has anyone with this problem taken it in to the SC and got a confirmation that somethin' ain't right? My concern is that when I take it in they will say "Feels fine to me." and make some meaningless adjustment.
The graph visually didn't show much difference. But then I downloaded into Excel and I could see the differences. I took the absolute value of the acceleration data points and compared the average,median, and the top 10%. My Tesla numbers were 65-69% higher than the X5, They were significantly higher than the air demo and the other coil as well on the highway. Still need to download some other runs before I publish the numbers for those.
The seats were the same on the coils (stock seats) I think the air was leather. I don't buy for a second that the differences are due to the seats.
The seats were the same on the coils (stock seats) I think the air was leather. I don't buy for a second that the differences are due to the seats.
mspohr
Well-Known Member
It might be useful to look at some of the analysis that VibSensor does. The ISD, RMS vibration and Resonances could give useful information. In addition the Plot provides additional analysis of the Power Spectrum and vibration (filters out high frequency).
These analyses could provide additional insight beyond the raw data.
(Unfortunately, I'm not a mechanical engineer so my knowledge of this area is limited but perhaps someone with training in this area could provide additional insight.)
From the VibSensor manual:
Analyzing
The ViewData page allows access to all data collected with your device. The data is segmented first by day, then collection time. Select the data of interest to view the analysis page. There are two main elements to the analysis page:
Report: The report contains a summary of the data collection. Pay attention to the Gaps and Data Rate information - it will let you know if your device is acquiring up to its capability. The acceleration units can be changed in the main Settings page.
Peak raw: This indicates the maximum acceleration data recorded for each axis. LIMIT means that data occurred that was outside of the measurement range of the accelerometer.
ISD (Integrated Spectral Density): The power spectral density integrated from 0 Hz to the Nyquist frequency. For a constant vibration level, this should be equal to the RMS vibration level.
Resonances: These are identified from the calculated power spectral density. The top two resonances are shown for each axis, with the magnitude of each indicated in parenthesis next to the resonance frequency.
RMS vibration: This data is displayed in the report after the vibration data is viewed in the plot. It is the root-mean-square amplitude of the vibration data about zero.
Avg tilt: This data is displayed in the report after the tilt data is viewed in the plot. It is the average of the tilt data over the duration of the acquisition.
Plot: The plot allows interactive viewing of four types of data. The data type can be selected along the top of the plot. At the bottom of the plot is an interactive legend. Touch a legend entry to toggle that trace on or off. Also on the bottom is an x-axis scale factor. Touch to select the desired scale factor, then swipe to scroll through the data. The four types of data are:
power spectrum: The power spectrum is calculated from 0 Hz to the Nyquist frequency. The units are acceleration squared divided by the frequency. To integrate over the power spectrum, sum all data and then multiply by the frequency step size. This returns the mean squared amplitude in acceleration units squared. Both x and y axes can be toggled between linear and log by selecting the desired label next to the axis.
vibration: The raw accelerometer data high-pass filtered to emphasize vibration. The roll-off frequency is 1 Hz in high frequency mode, and 0.1 Hz in low frequency mode.
tilt: The raw accelerometer data low-pass filtered to emphasize tilt. The roll-off frequency is the same as for vibration.
raw: The unmodified accelerometer data from the device.
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