Charger 'floats' for 1-2 seconds after hitting bumps on highway- Is this normal?

[XH29N0G]

When I drive on the highway and hit a place where the pavement changes height (e.g., a bump near joints on bridges, redone pavement, etc....), it feels like the car drops down (I would say bottoms out but don't think it is hitting bottom) and then rises up, giving an uncomfortable floating feeling.  The wheels feel like they are on the road, but it doesn't feel like any other car I have driven. 

Is this normal for these cars?  Is there a fix? 

The car was restored 3 years ago, so shocks are not super old.

Any help or thoughts will be greatly appreciated.

[Mike DC]

Well, yeah, worn shocks is the first thing that comes to mind. 

What's the setup in general?  Stock torsion bar stiffness?  What shocks does it have?  How many miles?  Has the problem appeared over time or was it there since the resto was finished? 

[shorty442]

...someone put helium in the tires instead of nitrogen???

[garner7555]

That is a prime example of why so many of us put heavy (thicker diameter) torsion bars in, along with a good quality shock.         I would also recommend a big sway bar, but it will help in corners, not when hitting bumps as you describe.   

[440]

One persons opinion of floating is different to someone else's, plus it also depends what your comparing it to.

My wife always goes on about my tires being squirmy, she drives a Toyota 86 which is like a go-cart. My car is nearly 40 years old and has big bulgy oversized tires so of course it's going to squirm around, but it's normal to me.

[XH29N0G]

Suspension: The car was ordered with Heavy duty suspension which would be 0.92 inch torsion bars, front sway bars, and Hemi Springs.  

Miles:  It has about 5000 miles on it since the rebuild.  

Modifications: The front is lower than it should be because I put 0.5 inch shims between the K-frame and the frame rails and needed to lower it to get a level ride height.  It is 26 inches to the top of the wheel arches except for rear left which is slightly higher.  It has big tires (245 60 15 front/255 60 15 rear) now.  

Shocks: The shocks appear to be monroematic 32073 and 32022.

How long has this been happening:  My memory is not good enough to compare to what it did in 2011 and before.

Comparison: to modern cars (1999/2000 Volvo station wagon and sedan)

PS.  Thanks for the feedback

[440]

I would give a new set of shocks a try with more damping control.

KYB's were known for being "stiff" compared to other brands, they are cheap so I'd give them a try first.

[469 runner]

Those Monroematics should be replaced.  They are really designed to offer a smooth ride for everyday driving.  Get some Bilsteins sold through Firm Feel. Or, QA1's which offer adjustability.  Huge improvement.  Much more stable ride.

[cdr]

as said the Monroe matics are for a smooth ride like a floating boat !!!

[469 runner]

Also, KYB's are an improvement offering much more damping, but really lack any refinement at all.  They are just stiff.  Really stiff.  With a good quality shock you will still have a smooth ride and much more control when it is needed.  The QA1's I put on my car were over $130 each I believe.  Well worth it.  Bilsteins are a little cheaper.

[JR]

I agree with changing shocks, sounds like they're shot.

[Mike DC]

 

Replace the Monroe shocks with something better and see what happens. 

[XH29N0G]

Thanks for the advice.  This will be one of my next changes.

[440]

I have nothing but good things to say about Bilsteins. Nice firm ride without being harsh. When I bought them the ride quality was described as a "euro ride." Personally I think they were/are the perfect choice for a street car.

[Kern Dog]

KYB Gas-A-Just wee a popular shock for while. I ran them in my 70 Charger but after awhile, I wondered why other guys suggested Bilsteins so often.
The KYBs are a "digressive" design. This means that while going through small ride height changes going down a relatively smooth road, they feel stiff. This gives the driver the impression that the car responds better in turns, braking, etc. Trouble is, the longer the wheel travels, the SOFTER the shock gets! Yes, that is right, they work opposite of the springs! As a spring compresses, it gets stiffer until it runs out of travel. As the KYBs compress, they get softer and softer. What a stupid design!
The Bilsteins that most commonly use for our cars are "Progressive" design. This means that going down the road, they soak up small bumps and road defects but as the suspension travels further, they tighten up. This gives a smoother ride but also better handling when the car wants to lean in a turn, dive during hard braking or squat during hard acceleration.
Basic cheap shocks under $40 apiece are often simple oil filled units that are soggy all through the range of suspension.
The .92 torsion bars are also not helping. In the 60s when a "soft ride" was a great sales tactic, they may have been okay. Newer cars have a much stiffer spring rate yet still ride smoother. I run 1.15s and Bilsteins in my aluminum headed 440/493 Charger. It rides about as firm as my wife's 2015 Challenger R/T.

[XH29N0G]

Thanks, everyone, for all of the detailed input.  I think I will try the bilsteins this winter.  Changing other parts of the suspension will be for the not too distant future.

[Mike DC]

The KYBs are a "digressive" design. This means that while going through small ride height changes going down a relatively smooth road, they feel stiff. This gives the driver the impression that the car responds better in turns, braking, etc. Trouble is, the longer the wheel travels, the SOFTER the shock gets! Yes, that is right, they work opposite of the springs! As a spring compresses, it gets stiffer until it runs out of travel. As the KYBs compress, they get softer and softer. What a stupid design!

It took me a while to understand it but digressive valving isn't bad.  It does help handling on bumps when the valving goes softer from faster shock movement.

For a long time I was thinking of shocks as being there to help protect the chassis from bottoming-out on bumps.  But they aren't.  (not on a sports car anyway)  Shock designers treat a car like it will never bottom-out and there is no risk from letting the suspension move.  If the valving suddenly goes floppy on an abrupt 2-inch bump, then the wheel moves up 2 inches . . and the bump doesn't kick the chassis up 2 inches.  

For handling purposes it's better to hold the chassis basically level and let the wheels move to swallow the bumps & dips.  It works fine as long as the chassis isn't getting flexed all the way to hitting the bumpstops.  That rarely happens in normal conditions.


As for the KYB vs Bilstein issue, yeah, the KYB's are stiffer than I like.  

[HPP]

KYB also has a high pressure nitrogen charge inside them to go with the divergent valving. That can make that initial hit feel rather rough.

[alfaitalia]

KYB Gas-A-Just wee a popular shock for while. I ran them in my 70 Charger but after awhile, I wondered why other guys suggested Bilsteins so often.
The KYBs are a "digressive" design. This means that while going through small ride height changes going down a relatively smooth road, they feel stiff. This gives the driver the impression that the car responds better in turns, braking, etc. Trouble is, the longer the wheel travels, the SOFTER the shock gets! Yes, that is right, they work opposite of the springs! As a spring compresses, it gets stiffer until it runs out of travel. As the KYBs compress, they get softer and softer. What a stupid design!
The Bilsteins that most commonly use for our cars are "Progressive" design. This means that going down the road, they soak up small bumps and road defects but as the suspension travels further, they tighten up. This gives a smoother ride but also better handling when the car wants to lean in a turn, dive during hard braking or squat during hard acceleration.
Basic cheap shocks under $40 apiece are often simple oil filled units that are soggy all through the range of suspension.
The .92 torsion bars are also not helping. In the 60s when a "soft ride" was a great sales tactic, they may have been okay. Newer cars have a much stiffer spring rate yet still ride smoother. I run 1.15s and Bilsteins in my aluminum headed 440/493 Charger. It rides about as firm as my wife's 2015 Challenger R/T.

No...and no!
From KYB;

Digressive Shocks: These are the latest development in shocks and are the opposite of the progressive type. As the shaft speed increases the damping forces increase at a decreasing rate. (Yes, that's a confusing way to say it.) Digressive shocks still provide low speed damping without being excessively harsh on rough roads and still increases damping at higher speeds, but at a more reasonable and predictable rate. Digressive shock designs are what allow rally cars tackle intense terrain at high speeds.

So basically they don't actually get softer....they still get firmer but at a slower rate as the stroke increases. Shocks don't need to get firmer as the suspension stroke progresses to stop bottoming out...that's the springs/torsions bars and eventually bumpstops job.

[303 Mopar]

KYB's are junk.  Bilsteins are the best bang for your buck unless you want adjustable.

[alfaitalia]

Since Billys are about twice the price of KYB (at least here in the UK) you would kinda expect them to be rather better! I was going to put them, Bills, on my Grand Cherokee....until I read the warranty which basically said your warranty was void if you used it off road...WTF...its a 4X4!!! So I went KYB gas adjusts. To be honest they do not feel any different to the Billsteins on my friends Grand....if anything slightly firmer damped....but I always found Bills slightly under damped, for my tastes no matter what the application. You pays yer money...ya takes ya choice!!

[XH29N0G]

I'm waiting till the start of the next cc billing cycle to buy them, also want to see what the holidays have in store for spending.  But I'll report back.  I am planning on the Bilsteins.

[Kern Dog]

Uhhh.....

:No...and no!
From KYB;

Digressive Shocks: These are the latest development in shocks and are the opposite of the progressive type. As the shaft speed increases the damping forces increase at a decreasing rate. (Yes, that's a confusing way to say it.) Digressive shocks still provide low speed damping without being excessively harsh on rough roads and still increases damping at higher speeds, but at a more reasonable and predictable rate. Digressive shock designs are what allow rally cars tackle intense terrain at high speeds.

So basically they don't actually get softer....they still get firmer but at a slower rate as the stroke increases. Shocks don't need to get firmer as the suspension stroke progresses to stop bottoming out...that's the springs/torsions bars and eventually bumpstops job."


So what? KYB makes a claim and I'm supposed to just accept it? I don't blindly accept politicians that want to get into my wallet. I'm using the same methodology here.

KYB gas a just shocks are cheap for a reason, just like toilet paper from the Dollar Store or tools from Harbor Freight. 

[XH29N0G]

Uhhh.....

:No...and no!
From KYB;

No, I think I'll buy them.   

I also don't blindly accept politicians, but I think we are on different sides.  We will see how things turn out.   

[Brass]

I have the Bilsteins and I'm completely happy with them on my street car.  But you might like the QA1 double-adjustable shocks if you're going to the drag strip with any regularity.

[XH29N0G]

Thanks,  Those look nice, but more costly than the Bilsteins.  While I have just started taking the car to the drag strip and like it, I don't think I have enough skill or do this enough to justify the expense at this time.