Not all coilovers are created equally..
When you're shopping for a suspension system for your car, there are so many choices out there. You can find coilovers for $399 or you can find them well beyond $4000. Why is one option 10x more expensive than the others? On the outside, they all look the same. It's not just what you can see that justifies the price...
There are a lot of aspects as to what determines the price of a set of coilovers. On the outside, you could have a camber plate with a spherical bearing or maybe you need to transfer over your OEM top mount. What is the shock casing made from? Commonly among the less expensive brands you'll find they are made of steel with a light coating of black paint. On higher end offerings, you'll find nickel plated or stainless steel shock bodies. Some shock bodies are made from aluminum. Another thing that sets them apart are the springs. Are they generic or are they brand name springs from H&R or Eibach? Some brands are just more expensive because of their name. They paid for the name by investing hundreds of thousands of dollars in research and development. You can buy the same suspension they use in NASCAR. It'll cost you, but you can do it. You know it's been tested.
That's just the stuff you can see...
What you can't see, what really makes a good shock, a good shock is whats inside. Go on any forum or FaceBook group and ask what everyone recommends. You'll likely get the same answer that's $899 on average. They're ok at best. They function and you can adjust ride height. Yippee. That recommendation is based on the best option they could afford. Or they just follow along blindly, buying whatever someone tells them to buy.
While that brand isn't terrible, they are by no means focused on a high-end product. They have built a suspension that allows for a good margin, allowing them to give them away for free and get [insert instafamous person's name] to push them. Marketing vs Quality. If someone gave you something for free, wouldn't you tell everyone to buy them? Sure..I would too.
The problem with them is they use the painted steel casing. When you run a threaded body over the paint (adjusting collars) and then moisture and oxygen set on the now bare steel with aluminum touching, that's a recipe for seized rings. You might as well just weld those collars in place.
On the inside you'll find the same components as everyone else. A rod, a piston, some shims, oil, a floating piston, and nitrogen. Everyone uses a chromoly rod of some kind. Here's where things get hairy...first component is the piston itself. This is basically the heart of your shock. Your common $899 suspension uses a chunk of steel which is heavy. If you learned anything in physics class you know it takes more effort to move something heavy. That energy becomes heat. As these components are contained in oil, heat causes oil to break down. Once the oil breaks down, it starts to lose viscosity and in some cases begins to turn into foam. The oil used in those $899 shocks is not very good at combating breaking down.
Our suspensions use a very light weight aluminum piston. Light weigh, less heat. The heat it does create is quickly dispersed as aluminum doesn't heat up like steel does. We also use a high-quality synthetic shock oil that has a much higher threshold of performance. The shocks are designed to have a lot of endurance in them. Endurance in a single use, and of course over the long haul.
The other often overlooked component is the shims, or shim stack when grouped. A shim is best described as a super thin, flexible washer. You'll find these on either side of the piston, with a different arrangement on the rebound side (bottom) and compression side (top). When you get a shock revalved, they are basically changing the diameter and thickness of the shims. I've seen some shocks that use something that looks more like a wafer than a shim. The cheap suspensions will have these shims that will get hot spots and will actually warp when heated. Again, heavy piston, oil breaking down, warped shims...that's a shock that'll never perform the same again.
Our shocks use a stainless steel shim. No scoring, no hot spots, no warping. If heat does become a factor, our shocks will quickly recover and keep powering on.
Lastly, the higher priced suspensions are priced as such because of their flexibility to the end user. For example, if you have a RaceWorks 172 shock; if you have thumbs, you can rebuild them yourself. Scary at first, sure. But you do one and you can do the other three with ease. The lower models; if you have a problem its generally cheaper and easier for them to just sell you a new shock. Servicing a 172 shock is typically a shot of nitrogen (either via needle valve or a schrader valve - like the valve on your tire). If you need to replace the oil/ seals, release the nitrogen, remove the end cap with a flat blade screw driver, and push the guts through the bottom. Put it all back together by doing the reverse of the disassembly.
I'm not going to tell you "Don't buy that $399 or $899 suspension." It'll probably serve you well for what you need, you'll save a few bucks, and that's always a good thing. But! If I've ever learned anything...or any phrase has never been truer, buy once, cry once.