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How to lower your car the RIGHT way: COMPLETE COILOVER GUIDE - YouTube
Channel: Donut Media
[0]
- We'll see how our ride height is,
[2]
just kinda took a guess in the dark so,
[6]
let's find out.
[8]
Oh (bleep)
[9]
Coilovers, it's like buying a new
[11]
better set of legs for your car.
[13]
I don't think there's anything out there
[14]
that can improve your
car's handling, looks,
[16]
and just your general smiles per gallon
[18]
as much as a new good set of coilovers.
[20]
Today I'm gonna go over
what coilovers actually are,
[23]
how they work, all the
vocab associated with em,
[25]
how to pick the right ones,
[26]
I'll show you how to
install 'em on the Miata,
[28]
and then we'll 'em for a test drive.
[30]
I'm Zach, this is Money Pit, let's do it.
[32]
(upbeat music)
[37]
So the job of the suspension of a car
[39]
is to absorb bumps and potholes
[41]
and make driving comfortable.
[42]
The problem is that auto manufacturers
[44]
usually make cars too comfortable,
[46]
and cars end up being
really squishy and soft.
[49]
Take a look at all the
body roll on the Miata.
[51]
On the stock soft suspension,
[53]
the forces of the weight of
the vehicle in the corner
[55]
just squash the outside suspension,
[57]
allowing the inside
suspension to stand up.
[59]
(upbeat music)
[61]
So this week we're gonna
replace that suspension
[64]
with these coilovers.
[65]
But before we do that,
[66]
we need to understand
what a coilover really is,
[68]
and how it works, so let's talk about it.
[70]
There are two major components here,
[72]
a coil spring over a shock absorber.
[75]
First let's look at the spring,
[76]
this is a coil spring,
[77]
or a big old piece of steel
[79]
wrapped up in coils.
[81]
So it looks like this, or
like this, or like this,
[83]
or like this, or like that,
[84]
and its job is to store energy
[86]
so that when its compressed
[87]
it always wants to return
to its original shape.
[89]
That's why your car always
returns to the same ride height
[92]
after hitting potholes or speed bumps
[93]
or whatever the hell the kids are hitting
[95]
on the streets these days.
[96]
Let's forget about the spring for a minute
[97]
and just look at the shock absorber.
[99]
It's kind of really he hero
of the whole setup here
[101]
because it's responsible
for absorbing and damping
[105]
all the shocks, bumps,
and potholes, et cetera.
[107]
So what do we mean when we say damping?
[109]
Well what we really mean is slowing down
[111]
the natural motion of spring oscillation,
[113]
or up and down bouncing.
[115]
So using this little spring,
[116]
if I just push it down and
immediately move my hand,
[120]
it just kind of jumps.
[121]
But if I push it down and
dampen its return to normal,
[125]
it's very controlled,
[126]
because I've controlled it.
[127]
So that's kind of what your
shock absorber is doing.
[129]
I know you've seen a car
[131]
with a blown shock absorber on the street.
[134]
That's what it looks like,
[135]
that is a shock absorber
not doing anything
[137]
and just letting your spring oscillate.
[139]
So how does your shocks do it, huh?
[141]
Well it's called
hydraulic resistance baby,
[143]
and it's really pretty simple.
[144]
In here there are a couple of chambers,
[147]
there's a hydraulic fluid chamber,
[148]
there's a high pressure gas chamber,
[150]
they're separated by a floating piston,
[152]
and then at the end of this rod
[155]
is a piston which lives
in that hydraulic fluid.
[157]
So that piston is forced up and down
[160]
with bumps in the road,
[161]
which forces that hydraulic
fluid that it lives in
[164]
through tiny little holes
or orifices in that piston,
[167]
and that's what dampens oscillation,
[169]
thanks to the resistance
of the hydraulic fluid
[172]
to flowing through those tiny holes.
[174]
The bigger the bump, the
harder the fluid is pushed,
[176]
and the more hydraulic
resistance, and heat, we get.
[179]
But what about that gas chamber, huh?
[181]
Why is that there?
[182]
It doesn't sound necessary.
[183]
Well it kind of is, many shock absorbers
[185]
also contain high pressure nitrogen gas
[187]
to keep pressure on the hydraulic fluid,
[190]
and that's important because
of something called cavitation
[192]
which doesn't have anything
to do with your dentist.
[195]
Cavitation is when the hydraulic fluid
[197]
begins to foam up due to
repeated rapid shocks,
[200]
and then once that fluid
foams up, or cavitates,
[202]
the shock is rendered
completely ineffective.
[205]
Think of it this way,
[205]
you have a can of soda, you shake it up,
[208]
nothing happens because
[210]
while it's still closed
it's under pressure,
[212]
so it's not foaming up.
[213]
It only foams up when you remove
the pressure by opening it,
[216]
and that's basically what's going on
[217]
inside a high pressure gas shock.
[219]
You're shaking the hell out of it,
[220]
but thanks to that pressure,
[222]
it stays unfoamy and super effective.
[225]
(upbeat music)
[228]
Okay, so this is a setup change.
[232]
- [Man Behind Camera] Is it?
[233]
- I think so.
[234]
All right, so now that we've
got a basic understanding
[236]
of what's going on in there,
[237]
let's get back to talking about coilovers.
[239]
Let's do a little vocab lesson.
[240]
Threaded body, adjustable damping,
[242]
pillow ball, ride height,
external reservoir,
[244]
spring rake, pressure, rebound,
[246]
what does any of that mean?
[248]
Fear not, it's just car parts baby.
[250]
So let's break it down, talk about some
[252]
of the different parts and features
[253]
that you'll come across on the hunt
[255]
for a set of coil overs for yourself.
[256]
Pretty much all performance
oriented coilovers
[259]
are gonna have a threaded body,
[260]
which means what it says.
[261]
The body of the coilover is threaded.
[264]
So that allows you to adjust the height
[266]
of the lower mounting bracketry,
[268]
which in turn adjusts the
ride height of the car.
[270]
So the threaded body also generally
[272]
allows coilovers to use
a threaded spring perch
[274]
which separates ride height
adjustment and the spring seat,
[277]
which I think needs some explaining.
[279]
You see, on some coilovers
[281]
you adjust the ride height by
adjusting the spring perch,
[284]
which if you're lowering the car,
[286]
you'd end up with your
spring perch really low,
[288]
which would mean the spring
would be all slack and rattly
[290]
when the suspension is unloaded.
[292]
So separating ride
height and spring preload
[294]
means that you can keep
your spring nice and snug,
[297]
and do whatever you want with ride height.
[298]
And it helps keep the pistons
travel in its intended spot
[301]
inside the shock body.
[302]
So it's really nice to have a set
[305]
with separated ride
height and spring perches.
[308]
All right, so some coilovers
offer adjustable damping,
[310]
and we already talked
about damping earlier,
[312]
so we already know what that is, right?
[313]
Well sort of, there are
two types of damping,
[316]
there's compression and there's rebound.
[318]
Rebound damping is
damping as the suspension
[320]
extends back to its normal position,
[322]
compression damping is the exact opposite.
[324]
It's damping as the suspension compresses,
[326]
or as you're hitting a bump.
[327]
So these two types of
damping are adjustable
[330]
by changing the hydraulic resistance
[332]
by changing the size of the orifices
[335]
that the hydraulic fluid is forced through
[336]
on that piston inside there.
[338]
So you can't see the holes in the piston,
[340]
because they're inside,
[341]
but what you can see
is how you adjust 'em.
[343]
It's usually just a little
clicky boy like this.
[346]
Like that.
[347]
So this has 12 clicks of adjustment,
[349]
from soft to firm.
[350]
Usually on most coilovers, like this one,
[352]
the rebound and compression
damping are tied together,
[355]
but on some of the higher end stuff,
[356]
you get separate adjustability
[358]
so you can tune your rebound
and compression damping
[362]
as you see fit, got it?
[364]
Okay, so.
[366]
- [Man Behind Camera]
That was a lot to take in.
[367]
- Yeah.
[370]
Roll back a little bit.
[371]
Now let's talk about the springs.
[373]
So let's start with the spring rate,
[375]
basically how stiff your spring is.
[376]
Empirically speaking,
or in American units,
[379]
if you have a spring with a
rate of 100 pounds per inch,
[383]
that means that if you put 100 pounds
[384]
on top of that spring,
[386]
it will compress one inch.
[387]
For reference there, the Miata springs
[389]
are eight kilograms per
millimeter in the front,
[392]
and six kilograms per
millimeter in the rear.
[394]
This is a front, eight
kilograms per millimeter.
[397]
So that is pretty basic and pretty easy,
[399]
but that's only if we're
talking about linear springs
[402]
like this one, this is a linear spring.
[404]
However, there are springs
[405]
that change how much they compress
[407]
depending on how much weight
they already have on them.
[410]
These are what's known
as progressive springs,
[412]
this means that the more a
progressive spring compresses,
[415]
the more it resists compressing further.
[418]
The closer coils compress first,
[420]
and then you get to the stiffer coils.
[421]
The softer coils will
absorb shocks and bumps,
[425]
while the stiffer coils
[426]
give you good handling characteristics.
[428]
Sometimes they'll also
be shaped like a cone too
[430]
where the diameter also changes.
[431]
Speaking of different types of coils,
[433]
sometimes you'll see
[434]
a second spring altogether
on a coilover, like this,
[437]
and that spring is not for doing anything
[440]
while you're driving.
[440]
That's just what's called a helper spring.
[442]
They're just in there to hold
the springs in the right place
[444]
when the suspension is unloaded.
[446]
So I think that's about
it for springs for now,
[449]
so now let's talk about our mounts,
[450]
our upper mounts or our top hats.
[452]
It's basically the bridge
[453]
between your suspension and your car.
[455]
So here we've got our nice aluminum mounts
[458]
with rubber in here.
[459]
So the rubber mounts will
absorb a lot of road noise,
[462]
and some vibration to keep the cabin
[463]
pretty quiet and pretty comfortable.
[465]
Some will have what's
called a pillow ball mount,
[467]
they are a spherical bearing
[468]
which means they're metal on metal.
[470]
Very crisp, very responsive,
[472]
nothing like a pillow.
[473]
Not all coilovers will actually come
[475]
with top hats or mounts,
[477]
so in that case you can
reuse your stock ones
[479]
if you want to, if they're in good shape.
[481]
On some coilovers you'll
get camber plates,
[483]
or you can add them later.
[484]
They're basically just top hats
[486]
that give you some graduated slots
[488]
so that you can slide your
whole coilover in and out
[491]
to adjust your camber.
[492]
But on the Miata they're kinda useless
[494]
because we've got a
double wishbone suspension
[497]
which means that the angle of the coilover
[500]
really doesn't make much of a difference.
[501]
So some shock absorbers will
have an external reservoir.
[504]
Why you may ask,
[506]
the reservoir generally relocates
[508]
that high pressure gas chamber
[509]
that we talked about earlier,
[510]
which means now the entire
shock body is full of fluid,
[514]
which battles cavitation even better
[516]
than just having that high
pressure pocket in there.
[518]
It also adds for a little
longer travel range
[520]
in the same shock body,
[522]
and the added fluid
that the reservoir adds
[524]
also adds a little greater heat capacity
[526]
to the whole system
[527]
so your shock can handle
more heat before it fades.
[530]
So that's good too.
[532]
So now that we know what coilovers are,
[534]
and how they work,
[536]
how do you know which
ones to pick for your car?
[540]
Yo check check, do not scratch or cause,
[542]
or cause surface defects
to the damper shaft.
[546]
Contains pressurized gas and oil,
[547]
do not puncture.
[549]
So the more features a coilover has
[550]
from the list of features
we were just talking about,
[553]
the more expensive they're
gonna be generally speaking.
[555]
You know if you're looking
for really good handling,
[557]
durability, longevity,
[558]
customer support that
you can actually call
[560]
and get something done with,
[562]
you should go with a coilover kind of
[563]
in this mid range category in my opinion.
[565]
Around 1000 to 15 or 1600
bucks for most platforms,
[569]
and of course you can spend more,
[571]
knock yourself out.
[572]
Honestly, nice suspension is,
[574]
as far as car parts go,
money pretty well spent.
[577]
But if all you wanna do is go lower,
[578]
you can also go the avenue
of lowering springs,
[581]
these days, it can be a good option
[583]
especially for some of
the fancy cars out there
[585]
that have like electronic damping control
[588]
and stuff like that.
[589]
There is a time and a place
for lowering springs I think,
[592]
but it's not this.
[593]
So I know there's probably
a few of you out there
[595]
waiting for me to say it,
[596]
so there is also air suspension.
[598]
There is some air suspension out there
[599]
that handles pretty damn well.
[601]
In my opinion it's never
gonna be quite as good
[603]
as a good coilover,
[604]
and they're just always
prone to leaks and issues.
[606]
Okay, so all that said,
[608]
these are what we picked,
[609]
which the picking is
probably the hardest part
[611]
'cause there are just so many options,
[613]
you get option paralysis.
[614]
And because installing them
is typically pretty easy.
[617]
It's probably gonna take you
[617]
like two to four hours depending,
[619]
it's always nice to have a helping hand,
[621]
have a buddy around.
[622]
You shouldn't need too many tools,
[623]
some wrenches, some sockets,
[624]
a jack and jack stands, that's
about it, let's do this.
[630]
Wash your hands.
[631]
(upbeat music)
[642]
All right so the first thing you gotta do
[643]
when you're gonna put new stuff in
[644]
is take the old stuff out.
[645]
So that's what we're gonna do,
[647]
it's really easy in theory
[648]
there's just two nuts at the top,
[650]
one big bolt at the bottom,
[652]
we also need to disconnect
our sway bar end link.
[655]
Our stock stuff is so long
[657]
that I think it's gonna be
a little bit of a battle
[658]
to get it out of the suspension.
[659]
Sir Ron, help.
[662]
Get in here.
[663]
- So close.
[670]
Ow.
[673]
- We got glue.
[674]
Alternatively, you can take
out the upper control arm
[676]
which makes this a lot easier.
[680]
- It's a boy.
[682]
(glass breaking)
[683]
(cat meowing)
[684]
- All right well the
front came out super easy,
[685]
so I'm expecting more
of the same on the rear.
[687]
We got two nuts on the
top inside the trunk here,
[690]
so we had to remove a
little interior stuff,
[692]
and then disconnect the sway bar,
[694]
pop out the big bolt at the
bottom of the stock suspension,
[697]
should come right out.
[701]
Pretty easy, now it's time
to put in the new ones.
[704]
First I wanna talk about
that height difference.
[706]
I don't know what ride height
[707]
ultimately we're gonna want to sit at,
[709]
so I'm gonna match them all up,
[712]
make them all this size, then install 'em,
[714]
and then we'll adjust
ride height to our taste.
[717]
They go in a lot easier
than they came out.
[723]
So the torque spec for the lower bolt here
[726]
is 54 to 69 foot pounds,
[728]
so 69 it is boys.
[747]
All right so when you're
tightening any rubber bushings
[749]
in your suspension,
[750]
it's important to do that at ride height
[751]
or else they'll kind of always be bound up
[753]
because you tightened 'em when
the suspension was drooped,
[755]
and then you twist 'em up
as you go to ride height,
[758]
so when you're tightening rubber stuff,
[760]
tighten it at ride height.
[761]
You can do that with just putting a jack
[762]
under your suspension and
cranking it up a little bit
[765]
which is what I'm doing
here for the end links.
[768]
(upbeat music)
[774]
All right so we're all
done with the front,
[775]
time to move on to the rear.
[784]
We're running out of light and quick,
[785]
so I'm gonna tighten up the
rear ones, 69 foot pounds,
[788]
get that rear sway bar on, beautiful.
[791]
All right all four suspensions are on,
[793]
so now it's time to roll them fenders.
[795]
This is our fender roller,
[797]
it goes on the hub like so,
[798]
you can also get pretty far with a hammer,
[800]
in fact I'm gonna start with this
[802]
and then we'll probably
use this to finish up.
[805]
Kind of just get that fold started.
[811]
In case you haven't talked
to your neighbors in a while,
[813]
do this and trust me, you'll talk to 'em.
[818]
Hammer portion done.
[820]
Roller portion next.
[823]
Boy, I don't know if this
is gonna go short enough.
[826]
Um, (bleep) maybe it'll
work on the fronts.
[829]
Well our fender roller doesn't
fit in the front either,
[831]
it's just too long for the
Miata's tiny wheel wells,
[835]
so I guess that means
[836]
we're just doing the
whole thing with a hammer
[838]
which is honestly fine in my opinion,
[840]
you can get very good
results with the dead blow,
[842]
that's how I've done it in the past.
[844]
I was hoping to be able to
show you how that thing worked,
[846]
but it's very simple,
[847]
you'll figure it out
if you ever get there.
[850]
Maybe we'll be able to use
it on something else someday.
[852]
Anyway we're just gonna
hammer these fenders
[854]
and get it done with, you know.
[859]
All right we're gonna put the
old wheels and tires back on
[861]
and if you remember from last episode
[863]
I forgot to buy hub centering rings,
[864]
but I got some.
[866]
So in they go.
[868]
We'll see how our ride height is,
[870]
just kinda took a guess in the dark so,
[874]
let's find out.
[875]
Oh (bleep)
[877]
Well I'm pretty sure that's gonna rub.
[879]
That's gonna be close,
that's worth a drive
[882]
to see if that rubs.
[883]
All right so upon further review,
[885]
I don't think we're gonna be able to run
[886]
our precious little fender liners.
[888]
Maybe I'll be able to trim 'em up someday
[889]
and put 'em back in,
[890]
but for now we're going no fender liners.
[892]
All right so right now I'm
adjust the ride height on the car
[894]
to try to raise the front a little bit.
[896]
So to do that all I had to do
[897]
was break loose the lower collar
[899]
that locks in place the ride height.
[901]
You break that loose and then
spin the spring perch collar
[905]
with your wrench like this,
[907]
and it spins the body
in that lower bracket.
[911]
'Cause now the lower bracket's mounted,
[912]
it can't move, so we spin this,
[915]
and that changes our ride height.
[917]
Then we'll spin this collar back down,
[919]
lock it in place, call it a day.
[921]
All right so I'm just measuring
[922]
to see how much I've raised both sides
[924]
to make sure I do 'em kind of evenly.
[926]
Looks like I've got it even,
[927]
so we're gonna lock these down
[928]
and see how this looks.
[929]
You can also just measure the gap
[933]
from your tire to your fender as well
[934]
for measuring ride height.
[936]
But since we have this
open, we measure it there.
[942]
No rubbing, that ride height
looks pretty good to me.
[945]
Looks nice and low.
[946]
Before we go driving we
gotta do a couple tests,
[948]
first thing you're gonna wanna do
[950]
is turn the wheel all the way left
[953]
and all the way right,
[954]
ideally while rolling a little
[956]
to make sure nothing rubs, okay?
[958]
Nothing rubs.
[959]
Now meet me at the end of the driveway
[961]
for the second test.
[964]
This one's called the driveway test,
[966]
and it's whether or not
[967]
you can still get out of your driveway.
[971]
This Miatas great.
[974]
Let's go for a drive boys and girls.
[976]
(upbeat music)
[1002]
This thing feels great.
[1008]
So on hard bumps we still have
[1010]
a little bit of rubbing in the rear,
[1012]
so I'm gonna have to roll the
rear fenders a little bit more
[1015]
but otherwise it feels great.
[1016]
It's stiff, it's not too harsh,
[1018]
it's comfortable but it's not bouncy.
[1020]
So I'm really happy with this,
[1021]
so we lowered it today
[1022]
which means that we've
changed the alignment.
[1025]
So next week we're gonna figure out
[1027]
how to do a full alignment in the garage,
[1028]
so check me back for that
[1030]
next Wednesday on Money Pit,
[1032]
in the meantime follow me at Zach Jobe,
[1033]
follow Donut at Donut Media
[1035]
and I'll see you guys next week.
[1037]
Stay safe, wash your hands,
and keep your distance,
[1040]
see ya.
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