- Engines are air pumps
and the more air we can get into our engines,
the more power we can make.
One of the most tried and true ways
to get more air into an engine is by removing restriction.
Now our whole intake system,
apart from our new fancy filter set up
is pretty restrictive.
So what do we do?
Well, we'll replace it.
We'll replace all of it.
That's right.
We're gonna do a bigger intake manifold,
a bigger throttle body.
We're gonna get rid of our restricted mass airflow sensor,
and we're gonna fashion ourselves a new intake.
Then we're gonna take this thing back to The Dyno
and see how much more horsepower all those mods
will net us.
I'm thinking this is the first time
we're gonna break into the double-digit power gain zone.
- [Eddie] Double digits?
- Double digits, 10 or more.
- [Eddie] I'll be impressed. I'll be impressed,
- Prepared to be impressed my guy.
I'm Zach, and this is Money Pit.
Let's see if we can hit them double-digits baby.
(cheerful music)
So a few episodes ago,
we took the Miata to The Dyno
and we made a pretty unthreatening,
but altogether not too surprising 112 horsepower.
Now we've done an intake,
we've done an exhaust,
we've done an ECU.
We've done a few things
that should get us a little bit of power,
but we really haven't cracked in to the real power gain.
So let's take a look at what I've got for the car.
For our intake manifold,
I've got this six skunk2 intake manifold for the Miata.
So this thing is a little bit bigger in volume
and promotes airflow to make more power.
It also looks awesome.
It's generously cast,
so you've got plenty of room to port the runners,
if you so desire,
but I think we're just gonna leave it as it is for now.
And then we will be bolting on to it
skunk2's throttle body.
It's a really good looking piece.
And it's a little bit bigger than the factory one
for a little bit better airflow.
Now, right now, this probably isn't gonna net us
a huge power gain,
but we're gonna turbo this car.
And when we do this will really pay off then
because we're gonna be pushing a lot more air
through the engine
and the ability of these things
to flow that air will be super important.
So the first thing is always first,
we gotta get all the old stock stuff off,
and then we can start playing with our new fancy bits.
So come along on a magical journey
of taking off old 25 year old Miata parts.
(gentle music)
So right now we're just pulling apart some sensors,
taking off vacuum lines,
kinda nice,
kinda getting down to the bare intake manifold,
and then we'll pop it off. What I'm noticing so far is that
we've got a lot of brittle plastic,
two of my four fuel injector connectors cracked.
So that's sweet.
Otherwise, we're just kinda inspecting things,
looking for things that need fixed
or replaced while we're down here.
And we're gonna get a good look at our coolant reroute
to see how things are looking
make sure the hose isn't chafing where we routed it
or anything like that.
So should be good.
(gentle music)
Alright. We're about ready to take out the fuel rail,
which means we need to remove the fuel lines,
which means we're gonna lose some fuel.
Now, if I had been thinking ahead,
I would have removed the fuse
or the relay for the fuel pump,
and then I would have started the car
and let it use all the fuel that's up in the lines currently
before I took anything apart.
However, I didn't think about that.
So here we are.
If you find yourself in this situation,
just try to do what you can to catch the fuel.
I've got a bunch of paper towels
under the lines that should catch most of it,
is a little squirt there.
You know, not too bad.
There really wasn't much pressure in the lines,
which makes me wonder about the old fuel pressure regulator.
Probably needs replaced.
You can't wiggle this rail out of here.
(gentle music)
This thing needs cleaned bad.
All dirty babies.
Pretty impressive that these can work for as long as they do
and look so bad.
We'll replace them someday, but man, good work.
Alright. So I'm gonna jack the car up.
Basically, we're pretty far along
about as far as I can get on the intake manifold
from the top side,
I'm gonna jack the car up
so I can try to get to the hardware underneath the manifold.
'Cause those are the ones
that are gonna be really hard to get to.
Jack it up, get out from underneath
and everything will be fine.
(jack clicking)
That's gotta be enough.
Alright. There's a little stand for the intake manifold,
just a little support stand,
taking that off.
And that should give me a pretty good access
to these lower nuts.
(ratchet clicking)
All right. So we got to all the lower hardware.
I mean, it wasn't fun, but it wasn't that bad.
And I'm on my last nut.
I think this thing's ready to come off.
Let's find out if I forgot to disconnect anything.
(rattling)
Like I caught a fish.
- [Eddie] Yeah, I see it.
(camera clicks)
- All right.
Well there's that grimy old piece of trash.
I got some cleaning to do that's for sure.
But hey, that wasn't so bad.
That's basically like we're at the halfway point, right?
Now, from here on out we're just putting stuff back on.
Let's take a look at what we're putting on
and compare it to this old trash.
All right. So here are our stock parts, our old stuff,
and here's our new stuff.
So we'll take a brief look at the differences.
They're pretty simple in terms of the throttle body,
the old throttle body is about 58 millimeters
in terms of the diameter of the opening
and the new one is 64 millimeters.
So it's bigger.
Some more air can freely flow through.
And then when you look in to the manifolds,
this one doesn't look like it's gonna flow too well,
it looks a little, just looks a little restrictive.
And then you look in here
and you see these nice, big, smooth bell mouth
they just look built to flow.
And this is a two piece plenum.
So you can take this thing apart
and you can add like a spacer here
to increase the volume of your plenum
to suit your needs.
So the changes between these parts,
aren't super drastic.
It's just that these are a little bit bigger
and they improve flow.
And again, that's all we're doing here.
We're trying to remove restriction and improve air flow.
So these should do that pretty well.
Alright. So before we go ramming this manifold
onto the engine, we gotta prep it.
We gotta get it ready.
We gotta put some fittings in for all our vacuum lines
and all the things we need to connect to our manifold.
So that's what I'm doing right now.
It's gonna be pretty easy.
Use your MPT boys.
This wrench is too big,
but look at me using it anyway.
So we've got our vacuum fittings.
We got a little nipples in place.
Oh, you know what else we need to do?
No, that'd be the last thing we do.
Stick on the label.
That'd be the icing on the cake.
So this thing is ready to go in the car.
Let's go slam it.
We'll drop our gasket onto the studies.
And now did this not come with new nuts?
That is (beep) lame.
(beep)
So the runners on this manifold
come down a little bit lower than the stock ones.
And it's contacting the wiring on top of the starter.
I've already rotated the positive cable from starter
and that didn't quite give me enough,
but I think we'll be able to make it fit.
We just gotta do a little rearranging.
(people laughing)
Intake manifold is totally on now
and we're ready to focus our efforts on the throttle body.
So we've got to swap some stuff over
from the factory throttle body
to the bottom of the new throttle body.
So we'll go do that on the bench.
Then we can put the throttle body on
and start worrying about cleaning up all this stuff,
putting the fuel system back on,
these kinda things.
We're getting there.
All right. So this,
this little cooling tray
and I think this is our idle air control valve
or idle bypass valve.
Oh, yeah. I gotta figure that out for a new intake,
right?
Oh God.
You see?
(beep) Cubic feet of air out my ass
and it doesn't smell like anything,
such a bummer, such a letdown.
(grunting)
(farts) Oh.
(Eddie laughs)
On demand.
Here's one way to make a nice new throttle body look like,
(beep)
all right, this thing is ready to install.
Let's go do it.
(cheerful music)
Gorgeous.
It looks awesome.
There's a little bit of interference
with our coolant reroute.
It's got enough play to be fine.
Might need to tie it down somehow though.
All right, yeah.
I think we're gonna be able to work with this.
I'm gonna connect the coolant lines
to the bottom of the throttle body.
Then we'll start doing the fuel system.
I think this is going to work.
(cheerful music)
Alright. Now we've got our whole fuel system back in place.
And now it's just a matter of
plugging all our sensors back in,
rerouting all our vacuum lines
and kind of just figuring out where everything went.
I took everything apart kind of haphazardly
because all this stuff goes together pretty simply.
And it can really only go together one way.
It's not like I can really plug
the wrong thing into the wrong place in most cases.
So not too much to be scared of there
when it comes to plugging stuff back in,
just pay a little bit of attention and you'll be fine.
(cheerful music)
Broken connectors on there.
Pretty cool.
(cheerful music)
Now, when the only things I have left to do,
as far as the manifold and throttle about a year concern
is mount up the throttle cable
and connect it to the throttle body.
Yeah. My hands are a little bloody at this point,
but that's what happens.
There's a lot of sharp stuff in this engine bay.
(cheerful music)
Alright. So now the intake manifold
and the throttle body are fully installed.
Everything's good.
So now it's time to focus on our new intake.
Now the truth is it's gonna be a little bit janky
because it's totally temporary.
'Cause we're gonna turbo this thing soon,
and when we do our new intake will be useless.
So I just bought some odds and ends some silicone couplers
and some pipe, and we're gonna make an intake,
that'll go over to our racing beat filter,
and it'll let us delete our MAF.
So I'm gonna have to make a few cuts.
We've got most of our bands and silicone.
I'm gonna have to weld a bung
for a new intake air temp sensor into the pipe.
And I'm gonna have to weld a nipple
for our idle air control valve
so that we still have a good idle.
So we're gonna chop up some metal,
do some welding, make an intake.
(saw rattling)
It's good enough.
It's a little janky,
I'm aware, but it's all right.
It's certainly more free flowing than
the stock stuff with the MAF.
So it should perform pretty well
even if it looks a little atrocious.
All right, so on the idle air control valve nipple,
I found a little AN fitting laying around ,
totally not the right thing for the job,
but I'm gonna weld it onto one of the tubes
and it'll work good enough.
Where is my hose?
It'll basically just kind of thread into the hose,
(chuckles)
but I'm gonna open it up 'cause it's kinda small.
Originally there's, you know, a lot more airflow.
So I'm gonna open this up a little just to try to get,
make sure our idle doesn't do any weird stuff.
(drill whirring)
All right. My awful welding is complete
and the pipe has done.
It'll do for now.
It's temporary.
So now I've got a few things left to button up
before she's ready to start up.
I gotta wire up our new intake air temp sensor,
then get that plugged into the MegaSquirt
and get it all set up there. And then I have to relearn
the throttle position sensor position in the MegaSquirt.
Then I think this thing is ready to fire up
and then we go to The Dyno,
but we're gonna do that tomorrow.
For (beep) sake, this thing needs a battery so bad.
It's so annoying.
(engine stalling)
(beep)
(engine revs)
No big deal.
Alright. Well I guess that means it's time to go Dyno on it.
(cheerful music)
Alright, so we've got everything all dialed in
and we're finally ready to make some max power sweeps
to see how much max power the Miata can make now.
(cheerful music)
Everybody out there, I need you to cross your fingers for me
for that 122.
Come on, come on, come on.
(engine revving)
Hey 119.5. That's not bad.
That's 7.5.
(engine revving)
Wow.
120.07 horsepower.
We have seen the 120s.
It's still not 10 horsepower,
but I'll take it.
I'm in the taking mood today.
I'll take anything.
Okay. So we just got done dynoing
and we made a blistering 120 horsepower.
Now the car wind came in today, made 112 horsepower.
I wanted to make 10.
So this isn't quite the 122 we were looking for,
but still an eight horsepower gain on 112 horsepower cars,
still like an 8% increase,
which is pretty good statistically speaking.
And again, it's really ultimately honestly,
not about the numbers that we make today
because we're getting this thing ready to turbos.
It's all too easy to get wrapped up in the numbers
that you're making.
It's honestly, it's just not really about that.
This car as it is all 120 horsepower,
absolutely rips, even without a turbo.
So I think to celebrate entering the 120 horsepower zone,
I'm gonna take this thing for a drive today.
So thank you guys so much for watching.
I appreciate it so much. I really do.
Couldn't do it without you.
Thank you so much.
We'll see you guys next week.
In the meantime,
don't forget to follow me on Instagram @zackjobe,
and follow donut across all social media @donutmedia.
I'll see you guys next week.
Goodbye.