UPDATED: Replacing Rear Shocks: Reducing the rear end bounce.

[sukhoi_584th]

Using the "Physics Toolbox Accelerometer" android app, I took gyroscope readings this time instead of g-force meter. Although, I think it's all the same sensor. Will provide findings this week.

It's literally the same chip in your phone but not the same type of measurement. https://www.analog.com/en/technical...cceleration (specified,and d2 will not change.

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[Mach-Lee]

Alright, you guys got me excited so I decided to go body slam my Mach-E a few times for science:

That's 100 Hz accelerometer data. I put my iPhone on the trunk floor and then body slammed the tailgate briefly (immediately let up so it could rebound).

But holy cow, look at the valving. Rebound less damped than compression. You can also see the bounce afterwards, it's about 3 cycles long! Last, the natural frequency of the suspension is really close to 2.5 Hz, which is race car fast.

And for the nerds, here's a graph of jerk and snap (derivatives of acceleration). The data gets noisy but I can defiantly tell the rebound direction is more forceful than compression. Ideally the jerk decay should be balanced in both directions for optimal ride comfort.

So some work to be done here. I'd be happy if I could get the valving a bit more symmetrical to slow the rebound, get the bounce damped in under 2 cycles, and slow the frequency down to 2 Hz or less.

I've also attached the raw data file if anyone wants to do more with it. Just change the extension back to .csv (forum doesn't allow .csv file upload).

 

[kennethjk]

My premium extended battery has been much better on Florida roads than NY, although on a stretch of Florida turnpike where they are doing a lot of construction, I feel the “bounce “ again.

looking forward to your results as this mod can potentially help a lot of us

thanks for your work on this

 

[Mach-Lee]

Alright, you guys got me excited so I decided to go body slam my Mach-E a few times for science:

That's 100 Hz accelerometer data. I put my iPhone on the trunk floor and then body slammed the tailgate briefly (immediately let up so it could rebound).

But holy cow, look at the valving. Rebound less damped than compression. You can also see the bounce afterwards, it's about 3 cycles long! Last, the natural frequency of the suspension is really close to 2.5 Hz, which is race car fast.

And for the nerds, here's a graph of jerk and snap (derivatives of acceleration). The data gets noisy but I can defiantly tell the rebound direction is more forceful than compression. Ideally the jerk decay should be balanced in both directions for optimal ride comfort.

So some work to be done here. I'd be happy if I could get the valving a bit more symmetrical to slow the rebound, get the bounce damped in under 2 cycles, and slow the frequency down to 2 Hz or less.

I've also attached the raw data file if anyone wants to do more with it. Just change the extension back to .csv (forum doesn't allow .csv file upload).

And as a follow-up, here's a comparison of the Mach-E to my old Fusion, which has a great suspension. Same exact scales.

This shows how underdamped the Mach-E is. The Fusion damps everything in only 1 cycle vs. 3 for the Mach-E. The spring constant is less (car is much lighter) so there's more acceleration from my body force, but the bump is over with much faster than the Mach-E. The Fusion is the kind of graph we want.

 

[markboris]

And as a follow-up, here's a comparison of the Mach-E to my old Fusion, which has a great suspension. Same exact scales.

You can see the Fusion damps everything in only 1 cycle. The spring constant is less (car is much lighter) so there's more acceleration from my body force, but the bump is over with much faster than the Mach-E. The Fusion is the kind of graph we want.

Thanks for these graphs Lee. Anton will be doing more testing with graphs like this. While I understand it is important to actually see what is going on, both of us were really more focused on what we felt. Anton has been driving his car on these roads for over a year and is very familiar with it. Any little change and he can easily tell and the only time the car just about stopped bouncing was when the Koni's were adjusted to the firmest setting. Even my magneride has a slight more bounce than the Koni's did. Going over several different sized speed bumps, again only the Koni't had one cycle. It felt just like my ICE Mustang. I can't wait to try the Bilstein's this weekend.

 

[kennethjk]

Thanks for these graphs Lee. Anton will be doing more testing with graphs like this. While I understand it is important to actually see what is going on, both of us were really more focused on what we felt. Anton has been driving his car on these roads for over a year and is very familiar with it. Any little change and he can easily tell and the only time the car just about stopped bouncing was when the Koni's were adjusted to the firmest setting. Even my magneride has a slight more bounce than the Koni's did. Going over several different sized speed bumps, again only the Koni't had one cycle. It felt just like my ICE Mustang. I can't wait to try the Bilstein's this weekend.

Can the Koni’s be adjusted easily once installed?

 

[markboris]

G-force data would be accelerometer which is what you would want. And ideally you should have the phone be mounted to the vehicle so that it is reading the vehicles vibration and not the phones where it might be bouncing a bit more freely

While the phone was not bouncing, we had it in the front of the car on the charge pad and when I go back this weekend, we will test with the phone in the rear (I will be in the back seat taking the measurements). We will test the Koni's on their max firm setting, the Blstein's and then the OEM shocks.

 

[21st Century Pony]

And as a follow-up, here's a comparison of the Mach-E to my old Fusion, which has a great suspension. Same exact scales.

This shows how underdamped the Mach-E is. The Fusion damps everything in only 1 cycle vs. 3 for the Mach-E. The spring constant is less (car is much lighter) so there's more acceleration from my body force, but the bump is over with much faster than the Mach-E. The Fusion is the kind of graph we want.

Yeah this is very interesting data and it makes things factually clearer.

For the record, both Sonny Boy and I came from Fusion Energis. His was a new 2013 and mine was a new 2015... I bought mine because I liked his so much. Both our Fusions just ATE the OEM shocks... he put Konis on his and I put Bilstein B6s on mine. His rear shocks were hand-compressible in about 30k miles when we took them off... not that he's a gentle driver haha.

My butt dyno (on my Mach E ER AWD Premium) completely agrees with your graphs. KW coilovers, albeit at a salty price, completely solved the Pony Pogo for me with their superior design with adjustable damping settings. I am still working out some KW-induced camber issues in the rear wheel set thanks to the altered geometry...

 

[markboris]

Can the Koni’s be adjusted easily once installed?

Yes Ken they can be. The Koni has a large round knob that fits over the top of the protruding stem. However that dial is too large to fit on the stem once the shock is installed. I took one of the Dials and cut it down into a square that any 1/2" or 13mm wrench can easily turn. In order to get your hands in there, you do need to lift up the car slightly so you have to use a floor jack but only a couple of inches. You place the now square knob on the top of the shock and with one hand you hold the knob down on the stem and the other using the wrench to adjust.

However, when we adjusted the Koni's, the closer we got to the most firm setting, the better the ride so I personally would not suggest anything less than that setting. And again, it only adjusts the rebound. The compression virtually stays the same throughout the entire adjustment.

Unfortunately I did not take any photos when I was installing or adjusting the the shocks on Anton's car but I will this weekend.

Below is a photo of one of the knobs I cut down and at first I made it into a T but I then realized that would not work. I could only adjust with a wrench so I also cut down the T part and made it a square but never took a photo of it. I am sure Anton can snap a photo or I will this weekend.

 

[kennethjk]

Yeah this is very interesting data and it makes things factually clearer.

For the record, both Sonny Boy and I came from Fusion Energis. His was a new 2013 and mine was a new 2015... I bought mine because I liked his so much. Both our Fusions just ATE the OEM shocks... he put Konis on his and I put Bilstein B6s on mine. His rear shocks were hand-compressible in about 30k miles when we took them off... not that he's a gentle driver haha.

My butt dyno (on my Mach E ER AWD Premium) completely agrees with your graphs. KW coilovers, albeit at a salty price, completely solved the Pony Pogo for me with their superior design with adjustable damping settings. I am still working out some KW-induced camber issues in the rear wheel set thanks to the altered geometry...

To a layperson, are you saying the Koni’s were worn out after 30k miles?

Thanks

 

[21st Century Pony]

To a layperson, are you saying the Koni’s were worn out after 30k miles?

Thanks

No no - not at all. Sonny Boy's Konis lasted until he sold his Fusion.

His original OEM Ford rear shocks were, literally, compressible by hand when we took them off at about 30 [edit: thousand] miles to put the Konis on.

 

[kennethjk]

Yes Ken they can be. The Koni has a large round knob that fits over the top of the protruding stem. However that dial is too large to fit on the stem once the shock is installed. I took one of the Dials and cut it down into a square that any 1/2" or 13mm wrench can easily turn. In order to get your hands in there, you do need to lift up the car slightly so you have to use a floor jack but only a couple of inches. You place the now square knob on the top of the shock and with one hand you hold the knob down on the stem and the other using the wrench to adjust.

However, when we adjusted the Koni's, the closer we got to the most firm setting, the better the ride so I personally would not suggest anything less than that setting. And again, it only adjusts the rebound. The compression virtually stays the same throughout the entire adjustment.

Unfortunately I did not take any photos when I was installing or adjusting the the shocks on Anton's car but I will this weekend.

Below is a photo of one of the knobs I cut down and at first I made it into a T but I then realized that would not work. I could only adjust with a wrench so I also cut down the T part and made it a square but never took a photo of it. I am sure Anton can snap a photo or I will this weekend.

Now the interesting part will be after we know these work and it sure looks that way and we pick “the better option” , will an independent shop install making some of the modifications you mentioned

No way I would try

 

[Pushrods&Capacitors]

There are thousands of Mach-E owners that are very happy with the ride, then there are those that believe it is the worst riding car they have ever owned and then there are those in-between. One thing for sure, it has been a hot topic on this forum as evidence from one of the longest running threads we have ( #1 ).

There are so many variables with this issue and that's why I think we have a big discrepancy. Some owners with the magneride suspension love it and have no issues, others think it could definitely be improved, myself for starters. The non-magneride models are all different depending on standard battery, extended battery, RWD, AWD. Then we have the tires which really do make a difference on how the car rides as has been stated many times by owners, me included. Above all, there are the various types of roads everyone drives on. I have absolutely no roads anywhere within 2 hours of where I live that induce any bouncing and yet some owners have to drive over these types of roads every day. I can go on and on but these things have been beaten to death so I'm going to stop here.

I'm not any type of a suspension expert while many here are (Steve HuntingPudel for one) but wanted to set out to see what I could do to tame the bouncing of this car. I know if you put 6 or more cases of water in the cargo area, the bounce literally disappears. This tells me the car has very firm springs in the rear, as it should to handle the extra weight of a fully loaded car of passengers and cargo. However, when the car is not weighted down, over certain road conditions, it can bounce like the empty bed of a truck. I figured maybe what I could do is replace the springs with air bags and see how that goes. While I did have a great ride with a full air bag suspension, virtually no bounce, I had a lot of other issues that needed to be addressed in customizing brackets and spacers and after one month of doing this, I didn't feel like going at it any further ( #1 ). I could have gone the coil over route (KW make an excellent kit) but that is more on the expensive side for those who just want to try and soften their bucking pony driving to work.

Sticking with the OEM springs, the only other thing we can do to try and tame the ride is change out the shocks. Again, while I am not a suspension expert, I feel the shocks are not firm enough to settle the springs down fast enough. So, I set out to find shocks that would closely match our rear OEM's which I did and I'm testing them out with Anton (eidbanger) on his Premium with OEM wheels and tires. He does have aftermarket wheels and tires which actually make the ride a bit better but changed to the OEM's to keep it more fare since most people don't change their wheels and tires.

Last week, I posted on fitting and testing shocks in the bounce thread but thought maybe I should start a new thread on this subject ( #1,322 ) << Please read this post as it explains more about this project.
This post explains a little more about the particular shocks ( #1,325 )

Today, Anton had a bit of time so I went over to his place and installed the Koni's in his premium. Now, I am not use to Anton's car and he will be posting explaining in more detail how it rode and he will also have some data as he monitored each run with some type of motion app (not sure what it was). On the softest setting, they were worse than the OEM shocks. On the middle setting he said it was possiblely a bit better than OEM. Then went to the firmest setting and he had a huge smile on his face and said, my back end is barely bouncing. Again he will post here and explain in more detail with data but I know he would not let me take the shocks off the car. ? He wants to drive around with them for a week at which time I will go back down to his place and we will swap the Koni's for the Bilstein's.

On another note, we took my car out on the same stretch of bouncy road to see how the magneride did. With my car set to Unbridled, we both had a hard time finding a difference but decided if we had to pick, it would be the Koni's. Going over speed bumps at a slow speed, the Koni't definitely had the advantage as the rear went up, down and settled where as the magneride has a slight second bounce (which is why I think Ford needs to improve the tuning of the magneride VDM module).

Sorry for this long winded post. I wasn't sure even if changing out just the rear shocks would make a difference but it definitely does.

Both Anton and I will be adding to this thread as we do more testing. I think he may even post some charts off his motion app. He is backed up with work so don't expect him to post for at least a few days to a week.

I want to mention the Erik (azerik) is also working on some QA1 rear shocks and we are anxious to hear what his results are.

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Great post, thanks Mark. As someone with a “bit” of suspension tuning knowledge, your results are exactly as I’d suspect. My prior experience with Ford suspension tuning comes from various Mustang coupes over the years.

However, there is a common theme in almost all Mustangs up to the S550 generation and even including it in some cases: Ford’s chassis team seems to spec shocks and struts that are on the soft side for the spring rates they spec. So, you get what some drivers call bounciness or harshness when the shock/strut can’t control the body movement quickly enough in conjunction with the spring.

This tracks well with y’all’s findings that the Konis adjusted to a high stiffness setting actually smoothed out the bounce. It’s counterintuitive to the lay person but is exactly what you’d expect for a car with a spring rate not matched well to the Shock/strut damping curve.

On a personal note, I fought a similar issue in my ‘12 GT/CS that I was setting up for track work. The OEM shocks/struts were tuned too soft for even the OEM springs and when I initially added FRP “C” springs it got even worse. I originally thought the factory springs were too soft but it was the shocks/struts. So, after switching to guess what - Koni Yellows ? - the problem was solved, better rebound damping and a more planted feel than the Boss 302s I had driven.

 

[azerik]

On the middle setting he said it was possiblely a bit better than OEM. Then went to the firmest setting and he had a huge smile on his face and said, my back end is barely bouncing.

This confirmed what I was looking to do by choking the backend with rebound.

I'm setting up a 'test track of sorts. Going to a phone for the data, and another phone for video to try to overlay the data. Before I go tearing things apart I'll make a run around this track. It' 5 to 7 secontions of annoyance that I deal with daily. Then I'll hit it at different speeds. I won't play with the tire pressure until I get the shocks about where I want them. I'll also try to get measurements from the rear console. Possibly strapping the phone to the arm rest. Triggering the phone to record, is a whole other issue whilst driving though.


I'm currently on 2 year old stock tires. They're not bald, but their not new either, runing with 32f/34r psi. I'll also be trying to grab noise data over these sections as well as some cause a most wonderful 'womp' the reverbs through the whole car. I noticed the harder the tires the higher pitched this womp is. Around 30 psi was about unbearable as it turned into almost a base drum. Part of it being the shelf in the trunk reverbing as well. I also have gutted and dynamatted the trunk. When the car was like 19 hours old.. With the tires around 40psi they have a sharp noise to them over these expansion sections.

My goal with this was not just to fix my car but find where QA1's happy setting was for a bone stock car and see if we can have them build a custom valved shock as a direct replacement that's not adjustable. Some setting for compression but a much firmer rebound. But if they come back with a price thats as much or more than just buying the single or dual adjust shock, we'll just head down that road. (see what I did there?) They can build a custom coil over as well but I don't want to dip into KW territory. The only real concern for them is the strut mount that's welded to the strut body. I expect the QA1's to react about like the KW's as the settings look to be about the same shock for shock. I was also planning on dropping the rear sway bar to it's lightest setting at some point in the testing. But most of us here know how much that rear bar sucks to tighten the end links on.

@markboris Do you still have the old GT springs in the attic?

Now the interesting part will be after we know these work and it sure looks that way and we pick “the better option” , will an independent shop install making some of the modifications you mentioned

No way I would try

This is a straight shock swap. Preset the shocks before install. Adjust after if you see fit.

Oh yeah, and QA1's can be rebuilt all over the country. It's the lifetime warranty. As they arn't gas charged so it's more like the shocks I'm used to working on.

 

[markboris]

Now the interesting part will be after we know these work and it sure looks that way and we pick “the better option” , will an independent shop install making some of the modifications you mentioned

No way I would try

Ken, I don't think you understand how simple it is to retrofit these shocks to the car.

If you disassemble the top shock support on the OEM shocks, then you can use the bumpers stop and the top support without having to buy them. You need to drill the hole out just a bit bigger in the center of the shock support (I gave the drill sizes in one of my posts) and you need a couple of aluminum spacers to mount the shock to the top support. Assemble all to the shock and mount the shock to the car. Should I take more photos that the ones I took in this post? #1,322

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