- 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.
