mtxride

Most of my shock knowledge comes from mountain biking where shock valving is referred to as "fast" and "slow". So let me get this straight about the terms "soft" and "stiff". A "stiff" shock has smaller valving that makes the shock rebound and compress slowly, and a "soft" shock has larger valving that allows the shock to rebound and compress faster. Correct?

I understand how valving would affect articulation at slow speeds, but how does a "soft" or "stiff" shock affect sway on the highway at fast speeds, if it does at all?

Thanks for the help.

Flamedx4

Modern shocks are WAY more complex than that, but yes, you have the idea right. Most shocks today will have multiple valving that senses the speed the piston is traveling and allow for that - "blow off" for a big bump for example. They will also have different valving for compression than for rebound etc. There there are major engineering differences among brands & specific uses - single tube, double tubes, triple tubes, remote reservoirs, gas filled, gas cartridge, no gas, different gasses, single piston, multi piston, floating piston, all sorts of stuff. A shock should be uniquely vavled for your specific vehicle - there is no longer any universal design (except maybe for gramma's old Buick) and the wrong shock can ruin performance and handling on the street. It can be bewildering and a lot of it (like with anything these days) is bullsh** hype designed to make pretty magazine ads. Check some of the major shock manufacturers sites (Bilstein, Koni etc) and you can find some pretty good tech explanations. Don't put much faith in the claims of most of the 'offroad' shock companies (do you REALLY belive that Rough Country has more engineering expertise than say, Bilstein?) - very few of them build shocks or know anything about them, most of them just buy shocks from bulk manufacturers (like Monroe - half of the base model shocks sold by suspension companies are simply Monroes with pretty paint) - these are just fine too, but not exactly state-of-the-art.

mtxride

Thanks for the info, Flamedx4. You definently answered my question.
I knew about all the different valving and pistons and stuff, but was just trying to figure out the basics of how the OME soft and firm shocks are different for the 4runner.
so basicly, the softer shock will move a little faster than the more firm shock.

Unhappy99

Correct, and softer works great at lower speeds. As speeds increase, a firmer shock is required since there is more energy in the bumps to dissipate. Remember high schools physics? Energy goes up with the square of velocity.

If the shock is too firm at low speeds, it rides stiff around town. If the shock isn't firm enough at higher speeds, the vehicle handles like a boat, or a 4Runner with factory shocks.

mtxride

it all makes sence now. Thanks alot guys!!

Flamedx4

I worked with Bilstein back around 1990 to develop a shock for the RV chassis my company builds. They sent us various sets with different valving to try - and WOW what a difference there could be between shocks! UH99 hit the difficulty - how to get the best of both? A shock that is nice and soft could allow the RV to begin an up& down pitch cycle on bad expansion joint highways that was like riding a bucking bronc. Too firm and the jolts would eat your kidneys but the control was good. This is where velocity and pressure sensitive multi-stage valving really comes into its own. Interesting to note that a very tiny change in spring rate changed everything, and could alter the ride so much that the good shocks didn't do the job or the poor ones now did. This is where user-adjustable shocks are nice... Imagine how much more precise the fitment and engineering must need to be on your 4Runner than a 33,000 pound RV! The concept of shocks is so simple, but the devil is in the details.

The same goes for springs. With the same shocks, a lower spring rate could allow the shocks to exert more control and you get a cushy ride, but can start an excalating oscillation (overwhelming the shocks) if you encounter a few big bumps in a row - bad. Or an increase in spring rate could make it a handling and cornering whiz (and not necessarily give a harsh ride if the shock valving is sophisticated enough,) but could ALSO result in overpowering the shocks if you hit a few bumps and cause control issues. They must be engineered to work as a team. It's not easy and it isn't simple.

Flamedx4

[[but how does a "soft" or "stiff" shock affect sway on the highway at fast speeds, if it does at all?]]

It really doesn't affect sway. Even a "stiff" shock will move faster than than side-to-side weight transfer occurrs. Sway bar rate and bushing stiffness is really important here. But also the design of the suspension itself - some suspension designs naturally resist body roll much better than others, just as most modern front suspensions don't "dive" like they used to. Anti-dive and roll stability are engineered into the suspension to a large extent. Forces applied to the suspension in certain ways cause it to not resist, like when hitting a bump, but forces applied from another direction - perhaps like cornering inertia combined with body roll, cause it to resist movement and stiffen instead. Sway bars do the rest, or rather assist.

mtxride

I guess that's why I hear that alot of people get better rides with ome shocks and ome springs as opposed to ome shocks matched to another type of spring, or ome springs matched with another type of shock.

Flamedx4

Another thing that happens is a company does a great job with a setup for one rig, then they offer similar kits for other trucks and those suck... What works on one may not be great on another...

mtxride

ahh, now a million and one things to think about when doing suspension upgrades.