Softer Shock absorber options

-
C2ndLTpigeon

C2ndLTpigeon

Mopar or no Car!
Joined
May 18, 2019
Messages
1,140
Reaction score
895
Location
Indio California
I wanted to see if anyone knows of some other options for shock absorbers. I bought mine off Rock auto a year ago and they are the Grey KYB's for handling and stability but they are pretty stiff. My car is a 1973 Plymouth Valiant, and while stiffer struts are better for performance they suck for cruising.
 
If you search the forums you will see that many have been happy with the Bilsteins with their digressive valving. They are expensive but they will handle well and provide a comfortable ride. Plus a member of the forum you would be eligible for the FABO discount.

Thanks
James From
PST
 
Gabriel Red Riders. I think Auto Zone has 'um or can get them.
 
So what is better, a stiff shock or a soft shock on a big torsion bar? How about on a stock torsion bar? The white KYB's always get trashed in here for some reason. I have the white gas-adjust KYB's and they seem fine to me. The blue or green ones I took off were shot.
 
I would think that with the really big t-bars, you would scarcely notice the front shocks coming into play. You'd probably notice it more in the rear. My convertible has the stock slant six springs all around and white KYBs, and I think the ride is fine. It really soaks up the big potholes and heaves on poorly-maintained back roads. My FB has big block t-bars and HD rear springs with the same shocks, and it is much stiffer over bumps — you could definitely call it harsh. It also has front and rear sway bars, but those only come into effect if you are hitting the bump with one wheel instead of both wheels. But it really stiffens up the single-corner pothole impacts — my setup has no rubber in the end links.

For a smooth ride, I have heard Monro Sens-A-Trak recommended. No personal experience.
 
BYW, I didn't know KYBs came in colors. I have only seen the white ones. I presume the different colors represent different levels of performance? Which is what?
 
Bilsteins seem nice but they are spendy at the moment.
My Dad is going to run a set of blue Monroe's on his 70 Cuda, do they make a set for 73+ A bodies?
 
Monroe Gas-Matics.I have used those for years. Have them for A&B, +E,F,J,R. and more Mopars
The Gabriel Red Riders are a close second.
Pretty much the most basic shocks out there.
 
I guess your gray KYB is the old white model with a new paint scheme. They only got 4.5 out of 5 stars.
kyb-gas-shocks.jpg
 
pishta said:
Explain...inquiring minds want to know! Please compare the KYB to the Bilstein
Click to expand...

I'm sure @72bluNblu or @BergmanAutoCraft could explain it better but I'll give it a shot...

The first key thing to understand when dealing with shocks is that every vibrating system has a "natural frequency". This depends on the unsprung weight (wheel and tire, brakes, spindle etc for front or the entire rear axle), sprung weight (car itself) and the rate or stiffness of the spring. The system needs to have damping (shock absorbers on a car) in order to stop it from vibrating virtually forever or having the tires leave contact with the pavement and the required damping rate is based on the natural frequency. If the damping rate is too low (shocks are too soft) the car will bounce a lot after hitting bumps and have bad recovery time when making sharp turns. If it's too high the car will ride stiff and the springs won't be able to do their job properly.

So with that said different cars in different conditions need shocks with different damping rates. Unfortunately for classic Mopars you basically have cheap shocks that are either very soft/low damping rate to match up with factory spring rates or too firm like the KYBs. The higher-end shocks like Bilsteins in a nutshell have better control and react to different conditions better, as in going over potholes vs. driving fast on a twisty road because the way they work internally is more sophisticated. This is why adjustable shocks exist; when you want maximum suspension control you can dial-in the damping rate to match up with the spring rate and driving conditions. I actually plan to get adjustable shocks for my Duster since I do handling-oriented amateur racing stuff with it and the current stock replacements don't do jack with my 1.14" torsion bars, front and rear sway bars and Hotchkis rear springs.

KYB Gas-a-justs are good-quality shocks but they have progressive valving meaning the damping force is highest when the wheel is moving fast (over bumps or potholes) which is the opposite of what you want. In my experience they work best on trucks and 4x4s with big tires and lots of unsprung weight to keep things bouncing around too much. Bilsteins or other brands of high-performance car shocks have digressive valving which work the opposite; soft going over bumps but firms things up in hard cornering to keep the car stable and minimize unwanted weight transfer, like body lean.

So to the OP after all that, lol... if you just like to cruise your car and aren't concerned with making it handle super well go with some cheap Monroes or Gabriels, your ride will be much softer. Only downside in my experience is they're built like crap and like to blow out after not very long. I've had shocks from both brands go out within months of installing them. I know KYB makes an OE-replacement line of shocks called Excel-G which do ride soft, I've used them on other vehicles but I'm not sure if they have them in the right sizes for classic Mopars. In the past when I've searched by year/make/model for my Duster the Excel-G's didn't come up.
 
PST said:
If you search the forums you will see that many have been happy with the Bilsteins with their digressive valving. They are expensive but they will handle well and provide a comfortable ride. Plus a member of the forum you would be eligible for the FABO discount.

Thanks
James From
PST
Click to expand...
James, I have the white KYB's all around on my '70 Duster small block. They are a bit stiff, but thought I had to deal with that. My biggest issue is when I go over a dip in the road, the front end sometimes bottoms out. I have the ride height set pretty high because I am using the '73 front sway bar with the QA1 LCA's and it sits much lower than the OE sway bar. I would not mind spending the money for better shocks, but I would like to get something that will ride well but deal with the road dips.
 
@MopaR&D Thanks for the explanation! They are noticeable stiffer than the old green ones but I didnt know the damping was different from progressive to the digressive. I got an old set of blue ones somewhere if my teeth start to hurt.
 
Old saying from the old days working at Montgomery Ward Auto Service.
"IF they aren't Blue, they aren't new. Up sale folks for shocks when they bought new tires.
 
MopaR&D said:
I'm sure @72bluNblu or @BergmanAutoCraft could explain it better but I'll give it a shot...

The first key thing to understand when dealing with shocks is that every vibrating system has a "natural frequency". This depends on the unsprung weight (wheel and tire, brakes, spindle etc for front or the entire rear axle), sprung weight (car itself) and the rate or stiffness of the spring. The system needs to have damping (shock absorbers on a car) in order to stop it from vibrating virtually forever or having the tires leave contact with the pavement and the required damping rate is based on the natural frequency. If the damping rate is too low (shocks are too soft) the car will bounce a lot after hitting bumps and have bad recovery time when making sharp turns. If it's too high the car will ride stiff and the springs won't be able to do their job properly.

So with that said different cars in different conditions need shocks with different damping rates. Unfortunately for classic Mopars you basically have cheap shocks that are either very soft/low damping rate to match up with factory spring rates or too firm like the KYBs. The higher-end shocks like Bilsteins in a nutshell have better control and react to different conditions better, as in going over potholes vs. driving fast on a twisty road because the way they work internally is more sophisticated. This is why adjustable shocks exist; when you want maximum suspension control you can dial-in the damping rate to match up with the spring rate and driving conditions. I actually plan to get adjustable shocks for my Duster since I do handling-oriented amateur racing stuff with it and the current stock replacements don't do jack with my 1.14" torsion bars, front and rear sway bars and Hotchkis rear springs.

KYB Gas-a-justs are good-quality shocks but they have progressive valving meaning the damping force is highest when the wheel is moving fast (over bumps or potholes) which is the opposite of what you want. In my experience they work best on trucks and 4x4s with big tires and lots of unsprung weight to keep things bouncing around too much. Bilsteins or other brands of high-performance car shocks have digressive valving which work the opposite; soft going over bumps but firms things up in hard cornering to keep the car stable and minimize unwanted weight transfer, like body lean.

So to the OP after all that, lol... if you just like to cruise your car and aren't concerned with making it handle super well go with some cheap Monroes or Gabriels, your ride will be much softer. Only downside in my experience is they're built like crap and like to blow out after not very long. I've had shocks from both brands go out within months of installing them. I know KYB makes an OE-replacement line of shocks called Excel-G which do ride soft, I've used them on other vehicles but I'm not sure if they have them in the right sizes for classic Mopars. In the past when I've searched by year/make/model for my Duster the Excel-G's didn't come up.
Click to expand...

That's a great explanation. Don't think I could have done it any better.

The bottom line is that you want your springs and shocks to match, so that your suspension reaction is close to what they call "critically damped". Meaning, the suspension travels through its full range of motion for a given input (allowing it to suck up the bump while keeping the wheel fully planted on the ground), without letting the spring continue to oscillate after the input (allowing the wheel to remain in contact with the ground after the input is over and ready to track the next input). Underdamped suspension allows the springs to keep oscillating, most people have experienced because it's what you get with worn out shocks. You hit the bump and move down the road and the car is still riding like a wave. Overdamped is the opposite, the shock stops the suspension movement too quickly. That gives a harsh ride, and can cause a loss of traction because it will bounce the car rather than the suspension. The whole idea is to maximize the pressure of the tire on the road throughout the entire event so you have the best traction.

damping-graph-jpg.jpg


mvh said:
I would think that with the really big t-bars, you would scarcely notice the front shocks coming into play. You'd probably notice it more in the rear. My convertible has the stock slant six springs all around and white KYBs, and I think the ride is fine. It really soaks up the big potholes and heaves on poorly-maintained back roads. My FB has big block t-bars and HD rear springs with the same shocks, and it is much stiffer over bumps — you could definitely call it harsh. It also has front and rear sway bars, but those only come into effect if you are hitting the bump with one wheel instead of both wheels. But it really stiffens up the single-corner pothole impacts — my setup has no rubber in the end links.

For a smooth ride, I have heard Monro Sens-A-Trak recommended. No personal experience.
Click to expand...

Completely wrong. The larger the torsion bars the more important the shocks are to damp the reaction of the bars. Otherwise you have a suspension that's spring dominated, the pressure of your tires on the road oscillates with the springs instead of being maximized, so, you give up traction.

What you run on your convertible is basically what people that think that KYB's are good shocks run. You run a REALLY soft spring, with a really stiff shock. The result is an overdamped suspension system. From a subjective standpoint it doesn't feel terrible, because your stiff shocks are counteracting your soft springs. But the suspension reaction is not ideal for good handling, rather than working together to improve your handling your suspension components are fighting each other.

Your car with big block torsion bars rides stiff because KYB's are horrible. Their simple design results in a progressive response like MopaR&D explained. Basically, the harder/faster you hit the KYB's the stiffer they get. Which makes them completely awful for larger torsion bars. The overdamping gets worse, making the ride more harsh. At the extreme, they don't let the suspension travel as it should, which means you lose traction as the wheels don't track the road.

Ricks70Duster340 said:
James, I have the white KYB's all around on my '70 Duster small block. They are a bit stiff, but thought I had to deal with that. My biggest issue is when I go over a dip in the road, the front end sometimes bottoms out. I have the ride height set pretty high because I am using the '73 front sway bar with the QA1 LCA's and it sits much lower than the OE sway bar. I would not mind spending the money for better shocks, but I would like to get something that will ride well but deal with the road dips.
Click to expand...

Exactly the problem with soft springs and stiff shocks. The ride quality is stiff because the suspension is overdamped, BUT, the springs are really soft so on big bumps/dips the suspension still bottoms out because you don't have enough wheel rate to control the input and the shocks can't compensate and keep the suspension from bottoming.

You need larger torsion bars to keep the suspension from bottoming out, and better shocks to control the larger bars so your ride quality doesn't suffer.
 
72bluNblu said:
Exactly the problem with soft springs and stiff shocks. The ride quality is stiff because the suspension is overdamped, BUT, the springs are really soft so on big bumps/dips the suspension still bottoms out because you don't have enough wheel rate to control the input and the shocks can't compensate and keep the suspension from bottoming.

You need larger torsion bars to keep the suspension from bottoming out, and better shocks to control the larger bars so your ride quality doesn't suffer.
Click to expand...
I am running 1.03 TB's and new 5 leaf rear springs. The new bars did slightly stiffen up the ride, but not appreciably. The rear springs on the other hand really stiffened things up as the old ones were very tired. Again, I am not opposed to getting better shocks but just wanting to know if that would help eliminate the bottoming when I am going fast and the road dips. That is the only time I see this happen.
 
Ricks70Duster340 said:
I am running 1.03 TB's and new 5 leaf rear springs. The new bars did slightly stiffen up the ride, but not appreciably. The rear springs on the other hand really stiffened things up as the old ones were very tired. Again, I am not opposed to getting better shocks but just wanting to know if that would help eliminate the bottoming when I am going fast and the road dips. That is the only time I see this happen.
Click to expand...

I don’t think better shocks are going to solve that problem for you. If you’re bottoming 1.03’s you probably have a ride height/bump stop issue to deal with.

1.03’s shouldn’t be anywhere close to bottoming at the stock ride height. As you lower the car with the torsion bar adjusters you lose suspension travel. Bigger bars help compensate for that, but you can still lower too much. My car for example is as low as it can go, even with 1.12” bars and modified bump stops.

That’s the other thing, if you’ve lowered the car but are still running stock height bump stops you’ll bottom out all day long. I run 3/8” tall lower bump stops. I also run taller upper bump stops, which re-centers the range of travel around the new lower ride height.
 
72bluNblu said:
I don’t think better shocks are going to solve that problem for you. If you’re bottoming 1.03’s you probably have a ride height/bump stop issue to deal with.

1.03’s shouldn’t be anywhere close to bottoming at the stock ride height. As you lower the car with the torsion bar adjusters you lose suspension travel. Bigger bars help compensate for that, but you can still lower too much. My car for example is as low as it can go, even with 1.12” bars and modified bump stops.

That’s the other thing, if you’ve lowered the car but are still running stock height bump stops you’ll bottom out all day long. I run 3/8” tall lower bump stops. I also run taller upper bump stops, which re-centers the range of travel around the new lower ride height.
Click to expand...
The front height is much higher than stock because I needed clearance for the 73 style sway bar. The car does not bottom, but the sway bar hits the road when I am driving at higher speeds and hit a dip in the road. I have QA1 UCA and LCA's with the 1.03 bars.
 
Ricks70Duster340 said:
The front height is much higher than stock because I needed clearance for the 73 style sway bar. The car does not bottom, but the sway bar hits the road when I am driving at higher speeds and hit a dip in the road. I have QA1 UCA and LCA's with the 1.03 bars.
Click to expand...

Then I’d say you have to do something different with your sway bar. If you’re higher than stock ride height and still hitting that thing with 1.03’s it has to be hanging way down. The stock 67-72 sway bars limit ground clearance a little, but no where near enough to cause what you’re describing
 
You must log in or register to reply here.
-

Back
Top