help with SHOCK ABSORBER
help with SHOCK ABSORBER
6th Gear Member
Joined: Apr 2007
Posts: 10,468
From: California
KYB's ride like crap, they do provide better handling than stock, but at the cost of a lack of control on rough roads. Custom vlaved Bilsteins from Maier ride smoother than a stock ride but provide 10x more control...they actually ride better than the new Mustangs do. I've eaten potholes at 70mph on the highway with little more than a slight bump, that would have knocked your teeth out with KYB's.
Foghorn Leghorn
Joined: Dec 2006
Posts: 2,923
From: I reside in a near constant state of amazment.
Granted I don't drive it down any rough roads but that hasn't been my experience with the white KYB's at all.
But perhaps my butt isn't sophisticated enough to know when it is being subjected to a crappy ride.
But perhaps my butt isn't sophisticated enough to know when it is being subjected to a crappy ride.
6th Gear Member
Joined: Apr 2007
Posts: 10,468
From: California
If you put a set of the custom valved Bilstiens on you'd notice the difference. The car would corner noticeably better and ride like a Cadillac. It's hard to understand how different shocks make the car perform unless you've experienced them. I've run all sorts of shocks, including the white KYB's and currently on the Bilsteins. I can tell you, there's not even a comparison; the shocks are so far apart in performance and ride quality that it would blow your mind.
Unlike the majority of shocks, the Bilsteins use an acceleration sensitive regressive valving. That makes for a phenomenally better performing shock (but more expensive). The KYB's are a velocity sensitive progressive valve.
Valving that responds to acceleration is quicker to change damping characteristics than one that responds to velocity, so the shock is more responsive (the piston/rod doesn't have to accelerate up to the max speed before the valving changes damping to what's needed).
Regressive valving means that as the shock velocity/acceleration increases, the rate of damping doesn't increase as quickly. This is the hardest to engineer. Progressive is the easiest since it's how a fluid damped shock (which nearly ALL shocks are, even gas charged shocks) reacts normally just because of the nature of fluid flow through orifices. That makes it the cheapest and easiest to engineer.
With shock motion, during cornering the shock moves at it's lowest rates; this is where you want it the stiffest to resist body roll and load transfer. With bumps and imperfections in the road, the shock motion is fastest....this is where you want the shock softer so the suspension can quickly respond to the road.
Progressive valving does the opposite....it causes the damping force to increase at a rate FASTER than the shock; so the shock is soft during cornering and stiff when responding to the road. Progressive was basically the first fluid shock technology, and is simple because with a fluid filled shock that's just how the fluid naturally causes damping as it flows through the valve.
Linear valving reduces that effect, by allowing more fluid flow at high shock motion; as a result the shock stiffness increases linearly with the shock motion. Regressive is designed so the damping increases at a rate that's LOWER than the shock motion. This means you can have a shock that's stiff under low motion (cornering) but doesn't get nearly as stiff under high motion (road bumps/holes); the result is better ride quality and control, and better handling.
All shocks increase stiffness with motion, it's just a matter of how much stiffer it gets with the severity of the motion. The ideal shock would be super stiff during little-no motion, but super soft during large motion such as a pot hole. The closest thing with fluid shocks is regressive valving.
The only thing better than regressive valving is electro-magnetic, which is still relatively new with only a few OEM cars having it; and it requires a lot of testing and design/programming to get right. But it can essentially provide that "ideal shock" characteristic.
Unlike the majority of shocks, the Bilsteins use an acceleration sensitive regressive valving. That makes for a phenomenally better performing shock (but more expensive). The KYB's are a velocity sensitive progressive valve.
Valving that responds to acceleration is quicker to change damping characteristics than one that responds to velocity, so the shock is more responsive (the piston/rod doesn't have to accelerate up to the max speed before the valving changes damping to what's needed).
Regressive valving means that as the shock velocity/acceleration increases, the rate of damping doesn't increase as quickly. This is the hardest to engineer. Progressive is the easiest since it's how a fluid damped shock (which nearly ALL shocks are, even gas charged shocks) reacts normally just because of the nature of fluid flow through orifices. That makes it the cheapest and easiest to engineer.
With shock motion, during cornering the shock moves at it's lowest rates; this is where you want it the stiffest to resist body roll and load transfer. With bumps and imperfections in the road, the shock motion is fastest....this is where you want the shock softer so the suspension can quickly respond to the road.
Progressive valving does the opposite....it causes the damping force to increase at a rate FASTER than the shock; so the shock is soft during cornering and stiff when responding to the road. Progressive was basically the first fluid shock technology, and is simple because with a fluid filled shock that's just how the fluid naturally causes damping as it flows through the valve.
Linear valving reduces that effect, by allowing more fluid flow at high shock motion; as a result the shock stiffness increases linearly with the shock motion. Regressive is designed so the damping increases at a rate that's LOWER than the shock motion. This means you can have a shock that's stiff under low motion (cornering) but doesn't get nearly as stiff under high motion (road bumps/holes); the result is better ride quality and control, and better handling.
All shocks increase stiffness with motion, it's just a matter of how much stiffer it gets with the severity of the motion. The ideal shock would be super stiff during little-no motion, but super soft during large motion such as a pot hole. The closest thing with fluid shocks is regressive valving.
The only thing better than regressive valving is electro-magnetic, which is still relatively new with only a few OEM cars having it; and it requires a lot of testing and design/programming to get right. But it can essentially provide that "ideal shock" characteristic.
Foghorn Leghorn
Joined: Dec 2006
Posts: 2,923
From: I reside in a near constant state of amazment.
Actually I have a Popular Mechanics circa 1977 with an article about electro-magnetic shocks.
I remember being amazed by the concept and ever since have wondered why they never used it and now, voila a short 35 years later and it's finally hitting the market.
I remember being amazed by the concept and ever since have wondered why they never used it and now, voila a short 35 years later and it's finally hitting the market.
6th Gear Member
Joined: Apr 2007
Posts: 10,468
From: California
I wonder how much of that was just a matter of having the supporting technology needed to make them work right. Modern computing and electronics make what once seemed impossible pretty easy these days.
