Bouncy stock highway ride - Konis or Bilsteins or...?

[tri-pedaler]

Loving my ‘15 ST, but….the highway ride is just too bouncy. I drive 20 miles to work, 14 of them highway, and other 6 through glorious river-road twisties.
Before anyone says just get used to it or put up with it, the issue is concrete highway sections - on asphalt it fine. If you’ve experienced this, you know what I’m talking about. At 70 to 80 mph the bounce is unbelievable!
I currently have stock shocks. I just got the car, so I'm not sure if these have 65k on them or if they've been replaced before.

I’m thinking of going with koni oranges or B4/B6s with the stock springs. I’d like to try that before swapping the rims to 16s. What is your experience been? Have you had bouncing at speed, and how did you fix it?

(Btw, not autoXing or doing track days, just my fun daily with a toddler seat in the back 😀 )

 

[unclefester]

15s don't fix it - i can't imagine 16s do either. They take out the harshness from the 17s but that 'Pogo' is still there. It's tiresome on longer journeys.

So far I've got around it by only using this as my Winter toy - it gets consigned to the corner of the drive the rest of the year and I'm on the bike or in the old Del Sol.

 

[Dpro]

Loving my ‘15 ST, but….the highway ride is just too bouncy. I drive 20 miles to work, 14 of them highway, and other 6 through glorious river-road twisties.
Before anyone says just get used to it or put up with it, the issue is concrete highway sections - on asphalt it fine. If you’ve experienced this, you know what I’m talking about. At 70 to 80 mph the bounce is unbelievable!
I currently have stock shocks. I just got the car, so I'm not sure if these have 65k on them or if they've been replaced before.

I’m thinking of going with koni oranges or B4/B6s with the stock springs. I’d like to try that before swapping the rims to 16s. What is your experience been? Have you had bouncing at speed, and how did you fix it?

(Btw, not autoXing or doing track days, just my fun daily with a toddler seat in the back 😀 )

Oranges will probably be to washy and disrupt handling . Get a set of Bilsteins or Koni Yellows.

 

[SteveS]

It partly depends on what you're getting on the concrete highway. If you're talking about a bounce from the joints between the slabs of concrete, then reducing harshness with a taller tire sidewall can help, and changing the spring/shock might help (it can, but it depends on what the settings of the spring/shock are. Most are aimed at stiffening things, not increasing compliance). If what you are experiencing comes from poorly poured concrete that has waves in it, nothing will really help short of super-soft, floaty suspension like old American cars have. We have a couple of sections of concrete like that on a new highway they put through town, and it really doesn't matter what car or truck I drive through there. The ride is annoying.

 

[TyphoonFiST]

Stock OEM 15' struts and shocks with Swift type R springs. Perfect*

Sent from my SM-N975U1 using Tapatalk

 

[Dpro]

If its expansion joints on freeways causing that bob effect indeed wheels with thires with a larger sidewall will go a long way towards softening that . I can speak first hand to that.

 

[Intuit]

.......... If you’ve experienced this, you know what I’m talking about. ................

Hehehehe... yeah. At particular speeds the rapid spring rate resonates with the road. About all you can do is either go faster or slower. Seems to be more pronounced with frigid temps. Fortunately it's more rare that I have to travel the particular sections of highway that resonate with the suspension.

In the meantime, find some good party (Fiesta) music to go along with it.

 

[tri-pedaler]

thanks all. I ordered some B4s just to see if that helps, since I suspect the original shocks have 65k on them. We'll see if this does anything for the pogo STick haha. otherwise loving this car.

 

[skippy]

thanks all. I ordered some B4s just to see if that helps, since I suspect the original shocks have 65k on them. We'll see if this does anything for the pogo STick haha. otherwise loving this car.

How did the b4s work out???

 

[TyphoonFiST]

Just about anything is better then stock OEM suspension* Even performance springs with OEM struts and shocks is a step up

 

[tri-pedaler]

How did the b4s work out???

to be honest, I'm underwhelmed with the difference unfortunately. At first I thought it was an improvement (placebo effect?), but then the weather turned cold again and I suspect the expansion joints in the highway shifted.

slight difference maybe - but still a pogo STick.

the good news is that when the weather gets warmer it should smooth out the highway.

and it was good to have an excuse to get under the thing, learn about it, and remove the previous owner's wheel spacers...

 

[TyphoonFiST]

to be honest, I'm underwhelmed with the difference unfortunately. At first I thought it was an improvement (placebo effect?), but then the weather turned cold again and I suspect the expansion joints in the highway shifted.

slight difference maybe - but still a pogo STick.

the good news is that when the weather gets warmer it should smooth out the highway.

and it was good to have an excuse to get under the thing, learn about it, and remove the previous owner's wheel spacers...

I Run NOS shocks and struts on Type R springs and it can be like a roller coaster/covered wagon on some roads. BUT* it's way better in the summer. I contribute this all to the winter....cold and contraction and expansion of the asphalt and concrete in Mn.

Sent from my SM-N975U1 using Tapatalk

 

[M-Sport fan]

to be honest, I'm underwhelmed with the difference unfortunately. At first I thought it was an improvement (placebo effect?), but then the weather turned cold again and I suspect the expansion joints in the highway shifted.

slight difference maybe - but still a pogo STick.

the good news is that when the weather gets warmer it should smooth out the highway.

and it was good to have an excuse to get under the thing, learn about it, and remove the previous owner's wheel spacers...

They are marketed as a direct OEM replacement damper, so maybe they just copied the factory valving parameters exactly?

I would still expect them to outlast, (and be able to handle more abuse without leaking than) the factory units by many many miles, regardless of them still being pogo sticks.

 

[Intuit]

Web search seems to reveal that bouncy suspension in frigid weather is more common than we know.

Thought I read something that explained why this occurs but that article was actually referring to hood and trunk struts.

Since fluid viscosity typically thickens as it cools, one would assume that the struts would stiffen as things got colder. But instead they do the opposite in many cases. Maybe it's dependent upon strut design... whether fluid/oil or gas/air. I do recall the struts (fluid/oil) in my prior car having less control in frigid weather. Figured that had something to do with them having over 300k on them but apparently not necessarily the case.

 

[M-Sport fan]

The Bilstein Heavy Duty dampers (I'm guessing the equivalent of their B6es for our rides? ) I installed on my '89 GTI 16V always seemed to be much, much firmer in frigid weather than when warm.

I surmised that this is because whatever fluid they are using in their dampers does not have a very high (or at least high enough?) viscosity index to be even close to as thin at below freezing temps as it is during spring/summer temps.

 

[unclefester]

My solution so far has been to avoid highways and stick to the back roads. Think I've just accepted that unless I'm prepared to throw 1/9th of the value of the car at the problem, it can stay as is.

 

[tri-pedaler]

maybe in light of the F1 tests going on right now we should rename this “Porpoising”??

 

[unclefester]

If i was Irish i'd say i like what you are purpoising

 

[XR650R]

I just bought the Koni orange rears. Haven't put them on yet, so I can't say how they'll do. They got pretty positive reviews here. https://www.fiestastforum.com/threads/very-happy-with-koni-str-ts.13336/

 

[M-Sport fan]

My solution so far has been to avoid highways and stick to the back roads. Think I've just accepted that unless I'm prepared to throw 1/9th of the value of the car at the problem, it can stay as is.

HA! The M-Sport R2 Reiger setup I desire for this car is more like HALF (or more) of it's current value, even in this inflated used car price market!