How to lower your car the RIGHT way: COMPLETE COILOVER GUIDE

- We'll see what our ride height is, we just took a guess in the dark so let's find out. Oh (beep) Coilovers, it's like buying a new pair of better legs for

your

car. I don't think there's anything that can improve

your

car's handling, looks, and just overall smile-per-gallon as much as a good new set of coil-over shocks. Today I'm going to go over what coil-overs actually are, how they work, all the vocabulary associated with them, how to choose the

right

ones, show you how to install them on the Miata, and then we'll talk. Em for a test drive.

I'm Zach, this is Money Pit, let's do this. (upbeat music) So the job of a car's suspension is to absorb bumps and potholes and make the ride comfortable. The problem is that car manufacturers often make cars that are too comfortable and the cars end up being very soft and mushy. Take a look at all the body roll on the Miata. In the original soft suspension, the forces of the vehicle's weight in the corner simply crush the outer suspension, allowing the inner suspension to rise. (upbeat music) So this week we're replacing that suspension with these coil-over shocks.

But before we do that, we need to understand what a

coilover

actually is and how it works, so let's talk about it. There are two main components here, a coil spring over a shock absorber. First let's look at the spring, this is a coil spring or a big old piece of steel wrapped in coils. So it looks like this, or like this, or like this, or like this, or like this, and its job is to store energy so that when it is compressed it always wants to return to its original shape. That's why your car always returns to the same ride height after going over potholes, speed bumps, or whatever kids are hitting on the streets these days.

Let's forget about the spring for a minute and just look at the shock. It's really the hero of the entire setup here because it's responsible for absorbing and cushioning all the bumps, bumps, bumps, etcetera. So what do we mean when we say cushioning? Well, what we really mean is slowing down the natural movement of the spring's oscillation, or bouncing up and down. So using this little spring, if I push it down and immediately move my hand, it just jumps up. But if I push it down and cushion it from returning to normal, it's very controlled, because I've controlled it.

That's what the shock absorber does. I know you've seen a car with a broken shock absorber on the street. That's what it sounds like, it's a shock absorber that does nothing and just lets the spring oscillate. So how do your shock absorbers do it, huh? Well, it's called hydraulic resistance, baby, and it's actually pretty simple. There's a couple of chambers here, there's a hydraulic fluid chamber, there's a high pressure gas chamber, they're separated by a floating piston, and then at the end of this rod there's a piston that lives in that hydraulic fluid. So the piston is forced up and down on bumps in the road, which forces the hydraulic fluid it lives in through little holes or holes in that piston, and that's what dampens the oscillation, thanks to the resistance of the hydraulic fluid to flow through. those little holes.

The bigger the bump, the harder the fluid is pushed and the more hydraulic resistance and heat we get. But what about that gas chamber, eh? Why is that there? It doesn't seem necessary. Well in a way it is, many shocks also contain high pressure nitrogen gas to maintain pressure on the hydraulic fluid, and that's important because of something called cavitation which has nothing to do with your dentist. Cavitation occurs when hydraulic fluid begins to foam due to rapid, repeated shocks, and then once the fluid foams or cavitates, the shock becomes

complete

ly ineffective. Think of it this way, you have a can of soda, you shake it and nothing happens because while it is still closed it is under pressure, so it doesn't foam.

It only foams when the pressure is removed by opening it, and that's basically what happens inside a high-pressure gas shock. You are shaking it a lot, but thanks to that pressure, it remains slightly foamy and super effective. (upbeat music) Okay, so this is a configuration change. - It is? - I think so. Al

right

, now that we have a basic understanding of what's going on there, let's get back to talking about coil-over shocks. Let's do a little vocabulary lesson. Threaded body, adjustable damping, cushioned ball, ride height, external reservoir, spring rake, pressure, rebound, what does it all mean?

Don't fear, they're just car parts, baby. So let's break it down and talk about some of the different parts and features you'll find when looking for a coil set for yourself. Almost all performance-oriented threaded shocks will have a threaded body, which means what it says. The

coilover

body is threaded. That allows you to adjust the height of the

lower

mounting bracket, which in turn adjusts the ride height of the car. So the threaded body usually also allows threaded shocks to use a threaded spring perch that separates the ride height adjustment and spring seat, which I think needs some explaining.

You see, on some coil-over shocks you adjust the ride height by adjusting the spring perch, which if you

lower

the car, you would end up with the spring perch too low, which would mean the spring would be loose and noisy when the suspension is unloaded. So separating the ride height and spring preload means you can keep the spring nice and tight and do whatever you want with the ride height. And it helps keep the piston travel in its intended location within the shock body. So it's really nice to have a set with separate ride height and spring mounts.

Alright, some shocks offer adjustable damping, and we talked about damping before, so we already know what that is, right? Well, there are two types of cushioning: compression and rebound. Rebound damping cushions when the suspension is extended back to its normal position, compression damping is the exact opposite. It dampens when the suspension compresses or when you hit a bump. So these two types of damping can be adjusted by changing the hydraulic resistance by changing the size of the holes that the hydraulic fluid is forced through into that piston that's inside. So you can't see the holes in the piston because they're inside, but what you can see is how you tighten them.

Usually it's just a little kid like this. How that. So this has 12 clicks of adjustment, from soft to firm. Typically, on most coil-over shocks, like this one, the rebound and compression damping are tied together, but on some of the higher-end products, you get a separate adjustment so you can adjust the rebound and compression damping as you see fit, understand? Well then. - That was a lot to take in. - Yes. Back up a little. Now let's talk about the springs. So let's start with the spring rate, basically how stiff the spring is. Empirically speaking, or in American units, if you have a spring with a rate of 100 pounds per inch, that means that if you put 100 pounds on top of that spring, it will compress one inch.

For reference, the Miata's springs weigh eight kilograms per millimeter in the front and six kilograms per millimeter in the rear. It is a frontal, eight kilograms per millimeter. That's pretty basic and pretty easy, but that's just if we're talking about linear springs like this, this is a linear spring. However, there are springs that change how much they compress depending on how much weight they already have on them. These are what are known as progressive springs, this means that the more a progressive spring is compressed, the more it resists being compressed further. The closest coils are compressed first and then the stiffest coils are reached.

Softer coils will absorb bumps and bumps, while stiffer ones will give you good handling characteristics. Sometimes they will also be cone-shaped where the diameter also changes. Speaking of different types of coils, sometimes you'll see a second spring in a shock, like this one, and that spring isn't for doing anything while you're riding. That is exactly what is called an auxiliary spring. They are just there to keep the springs in the right place when the suspension is unloaded. So I think that's it for springs for now, so now let's talk about our saddles, our top saddles or our top hats.

It's basically the bridge between your suspension and your car. So here we have our nice aluminum mounts with rubber. Therefore, the rubber mounts will absorb a lot of road noise and some vibration to keep the cabin fairly quiet and comfortable. Some will have what is called a pillow ball mount, they are a spherical bearing meaning they are metal on metal. Very crisp, very responsive, nothing like a pillow. Not all threaded shocks come with top hats or saddles, so in that case you can reuse the original ones if you want, if they are in good condition. On some threaded shocks you will get camber plates or you can add them later.

They're basically just top hats that give you some graduated slots so you can slide the entire spring in and out to adjust your tilt. But on the Miata they're a bit useless because we have a double wishbone suspension, which means the angle of the shock doesn't really make much of a difference. Therefore, some shock absorbers will have an external reservoir. You may be wondering, the reservoir usually relocates that high pressure gas chamber we talked about earlier, meaning the entire body of the shock is now filled with fluid, which combats cavitation even better than just having that high pressure pocket. pressure there.

It also adds a little longer range of travel in the same shock body, and the added fluid the reservoir adds also adds a little more heat capacity to the entire system so the shock can handle more heat before it wears out. fade away So that's good too. Now that we know what coilovers are and how they work, how do you know which ones to choose for your car? Check, check, do not scratch or cause defects on the surface of the shock absorber shaft. Contains gas and oil under pressure, do not puncture. So the more features a threaded shock has from the list of features we just talked about, the more expensive it will be generally speaking.

You know, if you're looking for really good handling, durability, longevity, and customer service that you can call and get something done, in my opinion you should go with a coil type shock absorber in this mid-range category. Around 1000 to 15 or 1600 dollars for most platforms and of course you can spend more, knock yourself out. Honestly, a good suspension is, as far as auto parts go, pretty money well spent. But if all you want to do is go lower, you can also choose to lower the springs; Nowadays, it can be a good option, especially for some of the fancy cars that have electronic damper control and things like that.

I think there is a time and a place to lower the springs, but this is not it. I know there are probably some of you waiting for me to say it, so there is air suspension too. There is some air suspension that handles quite well. In my opinion, they will never be as good as a good threaded shock, and they are always prone to leaks and problems. Well, with all that being said, this is what we chose, and choosing is probably the hardest part because there are so many options that you get option paralysis. And because installing them is usually quite simple.

It will probably take you between two and four hours, depending, it's always good to have a helping hand, to have a friend nearby. You shouldn't need too many tools, some wrenches, some sockets, a jack and stands, that's all, let's do it. Wash your hands. (upbeat music) Alright, the first thing you have to do when you're going to put in new things is take out the old things. So that's what we're going to do, it's very easy in theory, there are just two nuts at the top, a large bolt at the bottom, we also need to disconnect the stabilizer bar end link.

Our stock is so long that I think it will be a bit of a battle to get it out of suspension. Mr. Ron, help. Enter here. - So close. Oh. - We have glue. Alternatively, you can remove the upper control arm, which makes it much easier. - It's a boy. (broken glass) (cat meowing) - Okay, the front came out super easy, so I'm hoping for more of the same in the back. We have two nuts on the top inside the trunk here so we had to remove some interior material and then disconnect the sway bar, take out the big bolt on the bottom of the stock suspension, it should come out fine.

Easy enough, now it's time to put in the new ones. First I want to talk about that height difference. I don't know what ride height we're ultimately going to want to sit at, so I'll put them all together, make themthis size, then I'll install them and then we'll adjust the ride height to our liking. . They go in much easier than they came out. So the torque spec for the bottom bolt here is 54 to 69 foot-pounds, so 69 is guys. Alright, when you tighten the rubber bushings on your suspension, it's important to do it at ride height or else they'll always be tied up because you tightened them when the suspension was down and then you twisted them.

Go up as you reach ride height, so when you tighten the rubber material, tighten it to ride height. You can do this by simply placing a jack under the suspension and raising it up a bit, which is what I'm doing here for the end links. (upbeat music) Alright, we're done with the front, time to move on to the back. We're running out of light and speed, so I'm going to tighten the rears, 69 foot-pounds, and put the rear sway bar on, beautiful. Alright, all four suspensions are on, so now it's time to move the fenders. This is our fender roller, it goes on the hub this way, you can also get pretty far with a hammer, in fact, I'll start with this and then we'll probably use it to finish.

It's like starting that fold. In case you haven't talked to your neighbors in a while, do this and trust me, you will talk to them. Hammer portion ready. Next the roller portion. Wow, I don't know if this will be short enough. Um, (bleep) maybe it works on the fronts. Well, our fender roller doesn't fit in the front either, it's just too long for the Miata's small wheel arches, so I guess that means we're just doing everything with a hammer, which, honestly, is fine with me. opinion, you can I get very good results with the killing blow, that's how I've done it in the past.

I was hoping to show you how that worked, but it's very simple, you'll find out if you ever get there. Maybe one day we can use it on something else. Anyway, let's just hammer these fenders and be done with it, you know. Alright, we're going to put the old wheels and tires back on, and if you remember from the last episode I forgot to buy hub centering rings, but I have some. Then they enter. We'll see what our ride height is, we just took a guess in the dark so let's find out. Oh (bleep) Well, I'm pretty sure that's going to hurt.

That will be close, worth a drive to see if it works. Alright, after further review, I don't think we can use our precious little fender liners. Maybe one day I can trim them and put them back on, but for now we won't be using fender liners. Alright, now I'm adjusting the ride height of the car to try to raise the front end a little. So to do that all I had to do was release the lower collar that locks the ride height. You release it and then you turn the spring collar with your wrench like this, and it rotates the body on that bottom bracket.

Because now the bottom bracket is mounted, it can't be moved, so we rotate this and that changes our ride height. Then we'll twist this collar back on, lock it in place, and call it a day. Alright, I'm just measuring to see how much I've raised both sides to make sure they lay evenly. It looks like I have it tied, so we'll block them and see how it looks. You can also simply measure the space between the tire and the fender to measure the ride height. But since we have this open, we measure it there. No rubbing, that ride height seems pretty good to me.

It looks nice and low. Before we drive we need to do a couple of tests, the first thing you'll want to do is turn the steering wheel all the way to the left and all the way to the right, ideally while turning a little to make sure nothing rubs, okay? Nothing rubs. Now meet me at the end of the driveway for the second test. This is called the driveway test and it involves determining whether or not you can still pull out of the driveway. This Miata is great. Let's go for a walk, boys and girls. (upbeat music) This feels great.

On hard bumps we still get a little rub on the rear so I'll have to move the rear fenders a little more but otherwise it feels great. It's stiff, not too hard, it's comfortable but doesn't bounce. I'm very happy with this, so we lowered it today, which means we've changed the lineup. So next week we'll figure out how to do a full lineup in the garage, so come back to me for that next Wednesday on the Money Pit, in the meantime follow me on Zach Jobe, follow Donut on Donut Media and I'll see. you next week.

Take care, wash your hands and keep your distance, see you.