– We'll see how our ride height is, just kinda took a guess in the dark so, let's find out.
Oh (bleep) Coilovers, it's like buying a new better set of legs for your car.
I don't think there's anything out there that can improve yourcar's handling, looks, and just your general smiles per gallon as much as a new good set of coilovers.
Today I'm gonna go overwhat coilovers actually are, how they work, all thevocab associated with em, how to pick the right ones, I'll show you how toinstall 'em on the Miata, and then we'll 'em for a test drive.
I'm Zach, this is Money Pit, let's do it.
(upbeat music) So the job of the suspension of a car is to absorb bumps and potholes and make driving comfortable.
The problem is that auto manufacturers usually make cars too comfortable, and cars end up beingreally squishy and soft.
Take a look at all thebody roll on the Miata.
On the stock soft suspension, the forces of the weight ofthe vehicle in the corner just squash the outside suspension, allowing the insidesuspension to stand up.
(upbeat music) So this week we're gonnareplace that suspension with these coilovers.
But before we do that, we need to understandwhat a coilover really is, and how it works, so let's talk about it.
There are two major 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 up in coils.
So it looks like this, orlike this, or like this, or like this, or like that, and its job is to store energy so that when its compressed it always wants to returnto its original shape.
That's why your car alwaysreturns to the same ride height after hitting potholes or speed bumps or whatever the hell the kids are hitting on the streets these days.
Let's forget about the spring for a minute and just look at the shock absorber.
It's kind of really he heroof the whole setup here because it's responsiblefor absorbing and damping all the shocks, bumps, and potholes, et cetera.
So what do we mean when we say damping? Well what we really mean is slowing down the natural motion of spring oscillation, or up and down bouncing.
So using this little spring, if I just push it down andimmediately move my hand, it just kind of jumps.
But if I push it down anddampen its return to normal, it's very controlled, because I've controlled it.
So that's kind of what yourshock absorber is doing.
I know you've seen a car with a blown shock absorber on the street.
That's what it looks like, that is a shock absorbernot doing anything and just letting your spring oscillate.
So how does your shocks do it, huh? Well it's calledhydraulic resistance baby, and it's really pretty simple.
In here there are a couple of chambers, 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 is a piston which livesin that hydraulic fluid.
So that piston is forced up and down with bumps in the road, which forces that hydraulicfluid that it lives in through tiny little holesor orifices in that piston, and that's what dampens oscillation, thanks to the resistanceof the hydraulic fluid to flowing through those tiny holes.
The bigger the bump, theharder the fluid is pushed, and the more hydraulicresistance, and heat, we get.
But what about that gas chamber, huh? Why is that there? It doesn't sound necessary.
Well it kind of is, many shock absorbers also contain high pressure nitrogen gas to keep pressure on the hydraulic fluid, and that's important becauseof something called cavitation which doesn't have anythingto do with your dentist.
Cavitation is when the hydraulic fluid begins to foam up due torepeated rapid shocks, and then once that fluidfoams up, or cavitates, the shock is renderedcompletely ineffective.
Think of it this way, you have a can of soda, you shake it up, nothing happens because while it's still closedit's under pressure, so it's not foaming up.
It only foams up when you removethe pressure by opening it, and that's basically what's going on inside a high pressure gas shock.
You're shaking the hell out of it, but thanks to that pressure, it stays unfoamy and super effective.
(upbeat music) Okay, so this is a setup change.
– [Man Behind Camera] Is it? – I think so.
All right, so now that we'vegot a basic understanding of what's going on in there, let's get back to talking about coilovers.
Let's do a little vocab lesson.
Threaded body, adjustable damping, pillow ball, ride height, external reservoir, spring rake, pressure, rebound, what does any of that mean? Fear not, it's just car parts baby.
So let's break it down, talk about some of the different parts and features that you'll come across on the hunt for a set of coil overs for yourself.
Pretty much all performanceoriented coilovers are gonna have a threaded body, which means what it says.
The body of the coilover is threaded.
So that allows you to adjust the height of the lower mounting bracketry, which in turn adjusts theride height of the car.
So the threaded body also generally allows coilovers to usea threaded spring perch which separates ride heightadjustment and the spring seat, which I think needs some explaining.
You see, on some coilovers you adjust the ride height byadjusting the spring perch, which if you're lowering the car, you'd end up with yourspring perch really low, which would mean the springwould be all slack and rattly when the suspension is unloaded.
So separating rideheight and spring preload means that you can keepyour spring nice and snug, and do whatever you want with ride height.
And it helps keep the pistonstravel in its intended spot inside the shock body.
So it's really nice to have a set with separated rideheight and spring perches.
All right, so some coiloversoffer adjustable damping, and we already talkedabout damping earlier, so we already know what that is, right? Well sort of, there aretwo types of damping, there's compression and there's rebound.
Rebound damping isdamping as the suspension extends back to its normal position, compression damping is the exact opposite.
It's damping as the suspension compresses, or as you're hitting a bump.
So these two types ofdamping are adjustable by changing the hydraulic resistance by changing the size of the orifices that the hydraulic fluid is forced through on that piston inside there.
So you can't see the holes in the piston, because they're inside, but what you can seeis how you adjust 'em.
It's usually just a littleclicky boy like this.
So this has 12 clicks of adjustment, from soft to firm.
Usually on most coilovers, like this one, the rebound and compressiondamping are tied together, but on some of the higher end stuff, you get separate adjustability so you can tune your reboundand compression damping as you see fit, got it? Okay, so.
– [Man Behind Camera]That was a lot to take in.
Roll back a little bit.
Now let's talk about the springs.
So let's start with the spring rate, basically how stiff your spring is.
Empirically speaking, or in American units, if you have a spring with arate 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 there, the Miata springs are eight kilograms permillimeter in the front, and six kilograms permillimeter in the rear.
This is a front, eightkilograms per millimeter.
So that is pretty basic and pretty easy, but that's only if we'retalking about linear springs like this one, this is a linear spring.
However, there are springs that change how much they compress depending on how much weightthey already have on them.
These are what's knownas progressive springs, this means that the more aprogressive spring compresses, the more it resists compressing further.
The closer coils compress first, and then you get to the stiffer coils.
The softer coils willabsorb shocks and bumps, while the stiffer coils give you good handling characteristics.
Sometimes they'll alsobe shaped like a cone too where the diameter also changes.
Speaking of different types of coils, sometimes you'll see a second spring altogetheron a coilover, like this, and that spring is not for doing anything while you're driving.
That's just what's called a helper spring.
They're just in there to holdthe springs in the right place when the suspension is unloaded.
So I think that's aboutit for springs for now, so now let's talk about our mounts, our upper mounts or our top hats.
It's basically the bridge between your suspension and your car.
So here we've got our nice aluminum mounts with rubber in here.
So the rubber mounts willabsorb a lot of road noise, and some vibration to keep the cabin pretty quiet and pretty comfortable.
Some will have what'scalled a pillow ball mount, they are a spherical bearing which means they're metal on metal.
Very crisp, very responsive, nothing like a pillow.
Not all coilovers will actually come with top hats or mounts, so in that case you canreuse your stock ones if you want to, if they're in good shape.
On some coilovers you'llget camber plates, or you can add them later.
They're basically just top hats that give you some graduated slots so that you can slide yourwhole coilover in and out to adjust your camber.
But on the Miata they're kinda useless because we've got adouble wishbone suspension which means that the angle of the coilover really doesn't make much of a difference.
So some shock absorbers willhave an external reservoir.
Why you may ask, the reservoir generally relocates that high pressure gas chamber that we talked about earlier, which means now the entireshock body is full of fluid, which battles cavitation even better than just having that highpressure pocket in there.
It also adds for a littlelonger travel range in the same shock body, and the added fluidthat the reservoir adds also adds a little greater heat capacity to the whole system so your shock can handlemore heat before it fades.
So that's good too.
So now that we know what coilovers are, and how they work, how do you know whichones to pick for your car? Yo check check, do not scratch or cause, or cause surface defectsto the damper shaft.
Contains pressurized gas and oil, do not puncture.
So the more features a coilover has from the list of featureswe were just talking about, the more expensive they'regonna be generally speaking.
You know if you're lookingfor really good handling, durability, longevity, customer support thatyou can actually call and get something done with, you should go with a coilover kind of in this mid range category in my opinion.
Around 1000 to 15 or 1600bucks for most platforms, and of course you can spend more, knock yourself out.
Honestly, nice suspension is, as far as car parts go, money pretty well spent.
But if all you wanna do is go lower, you can also go the avenueof lowering springs, these days, it can be a good option especially for some ofthe fancy cars out there that have like electronic damping control and stuff like that.
There is a time and a placefor lowering springs I think, but it's not this.
So I know there's probablya few of you out there waiting for me to say it, so there is also air suspension.
There is some air suspension out there that handles pretty damn well.
In my opinion it's nevergonna be quite as good as a good coilover, and they're just alwaysprone to leaks and issues.
Okay, so all that said, these are what we picked, which the picking isprobably the hardest part 'cause there are just so many options, you get option paralysis.
And because installing themis typically pretty easy.
It's probably gonna take you like two to four hours depending, it's always nice to have a helping hand, have a buddy around.
You shouldn't need too many tools, some wrenches, some sockets, a jack and jack stands, that'sabout it, let's do this.
Wash your hands.
(upbeat music) All right so the first thing you gotta do when you're gonna put new stuff in is take the old stuff out.
So that's what we're gonna do, it's really easy in theory there's just two nuts at the top, one big bolt at the bottom, we also need to disconnectour sway bar end link.
Our stock stuff is so long that I think it's gonna bea little bit of a battle to get it out of the suspension.
Sir Ron, help.
Get in here.
– So close.
– We got glue.
Alternatively, you can takeout the upper control arm which makes this a lot easier.
– It's a boy.
(glass breaking) (cat meowing) – All right well thefront came out super easy, so I'm expecting moreof the same on the rear.
We got two nuts on thetop inside the trunk here, so we had to remove alittle interior stuff, and then disconnect the sway bar, pop out the big bolt at thebottom of the stock suspension, should come right out.
Pretty easy, now it's timeto put in the new ones.
First I wanna talk aboutthat height difference.
I don't know what ride height ultimately we're gonna want to sit at, so I'm gonna match them all up, make them all this size, then install 'em, and then we'll adjustride height to our taste.
They go in a lot easierthan they came out.
So the torque spec for the lower bolt here is 54 to 69 foot pounds, so 69 it is boys.
All right so when you'retightening any rubber bushings in your suspension, it's important to do that at ride height or else they'll kind of always be bound up because you tightened 'em whenthe suspension was drooped, and then you twist 'em upas you go to ride height, so when you're tightening rubber stuff, tighten it at ride height.
You can do that with just putting a jack under your suspension andcranking it up a little bit which is what I'm doinghere for the end links.
(upbeat music) All right so we're alldone with the front, time to move on to the rear.
We're running out of light and quick, so I'm gonna tighten up therear ones, 69 foot pounds, get that rear sway bar on, beautiful.
All right all four suspensions are on, so now it's time to roll them fenders.
This is our fender roller, it goes on the hub like so, you can also get pretty far with a hammer, in fact I'm gonna start with this and then we'll probablyuse this to finish up.
Kind of just get that fold started.
In case you haven't talkedto your neighbors in a while, do this and trust me, you'll talk to 'em.
Hammer portion done.
Roller portion next.
Boy, I don't know if thisis gonna go short enough.
Um, (bleep) maybe it'llwork on the fronts.
Well our fender roller doesn'tfit in the front either, it's just too long for theMiata's tiny wheel wells, so I guess that means we're just doing thewhole thing with a hammer which is honestly fine in my opinion, you can get very goodresults with the dead blow, that's how I've done it in the past.
I was hoping to be able toshow you how that thing worked, but it's very simple, you'll figure it outif you ever get there.
Maybe we'll be able to useit on something else someday.
Anyway we're just gonnahammer these fenders and get it done with, you know.
All right we're gonna put theold wheels and tires back on and if you remember from last episode I forgot to buy hub centering rings, but I got some.
So in they go.
We'll see how our ride height is, just kinda took a guess in the dark so, let's find out.
Oh (bleep) Well I'm pretty sure that's gonna rub.
That's gonna be close, that's worth a drive to see if that rubs.
All right so upon further review, I don't think we're gonna be able to run our precious little fender liners.
Maybe I'll be able to trim 'em up someday and put 'em back in, but for now we're going no fender liners.
All right so right now I'madjust the ride height on the car to try to raise the front a little bit.
So to do that all I had to do was break loose the lower collar that locks in place the ride height.
You break that loose and thenspin the spring perch collar with your wrench like this, and it spins the bodyin that lower bracket.
'Cause now the lower bracket's mounted, it can't move, so we spin this, and that changes our ride height.
Then we'll spin this collar back down, lock it in place, call it a day.
All right so I'm just measuring to see how much I've raised both sides to make sure I do 'em kind of evenly.
Looks like I've got it even, so we're gonna lock these down and see how this looks.
You can also just measure the gap from your tire to your fender as well for measuring ride height.
But since we have thisopen, we measure it there.
No rubbing, that ride heightlooks pretty good to me.
Looks nice and low.
Before we go driving wegotta do a couple tests, first thing you're gonna wanna do is turn the wheel all the way left and all the way right, ideally while rolling a little to make sure nothing rubs, okay? Nothing rubs.
Now meet me at the end of the driveway for the second test.
This one's called the driveway test, and it's whether or not you can still get out of your driveway.
This Miatas great.
Let's go for a drive boys and girls.
(upbeat music) This thing feels great.
So on hard bumps we still have a little bit of rubbing in the rear, so I'm gonna have to roll therear fenders a little bit more but otherwise it feels great.
It's stiff, it's not too harsh, it's comfortable but it's not bouncy.
So I'm really happy with this, so we lowered it today which means that we'vechanged the alignment.
So next week we're gonna figure out how to do a full alignment in the garage, so check me back for that next Wednesday on Money Pit, in the meantime follow me at Zach Jobe, follow Donut at Donut Media and I'll see you guys next week.
Stay safe, wash your hands, and keep your distance, see ya.