yo, on this episode of kpop RC we're doing professional development. what are
we doing today we're making practical sound effects.
let's make a blow-off valve I think we're also going to find out who
wins those seats in this episode so. you know, it could be you could be you.
leave me a comment below. I might send you some Recaro racing seats. I might send you
some. so leave me a comment below. yo welcome to kpop RC channel where I make
sick videos of scale models pretty much anything that's got a remote so don't
forget to sub up for giveaways and sick-ass RC content sometimes there's
fire. let's talk about making the blow-off valve.
you think we can build a blow-off valve?
alright what is a blow-off valve? a blow-off valve is a valve that
depressurizes the intake side of a forced induction setup what this does is
it stops the air that is rushing into the engine from backing through the
turbo when the throttle plate closes. the throttle plate closes when you take your
foot off the gas. when that happens, the intake plenum after
the throttle body is in vacuum that's because your throttle plate closes and
now the engine is pulling air not being force-fed air.
where is all that forced fed air going. well it's going right out the blow-off valve.
that's where you get the you get the sound those kinds of sounds,
You're nailing those sounds. those sounds come from that valve always. it happens when that
throttle plate closes. so the timing for a blow-off valve is super crucial to be
realistic. it can't happen when you're on throttle so what this particular
blow-off valve has to be pretty smart. it has to understand that when I give her
the throttle give her the jam. it was fully sick dude
and I'm holding that Jam and if I let go that Jam. that's when that blow-off valve
has to happen. not on the up of the RPM. that's not when it happens so we need a
microcontroller. a microcontroller that has some kind of if statement that would
kick my servo open and open a valve that would then let air out and then close
that valve at the right time. that would be how we make it realistic
and and actually make it sound like a real blow-off valve. I'm gonna do
car sounds for yous today, cah sounds, yeah. and before any of you dudes tell me to
go with like one of those electric speaker sound effects kit. that's not what
we're doing. let's see you go. go for gold buddy
we're building practical sound effects we want this to sound as realistic as
possible and I don't want it to sound like a looping sound effect and I don't
want it to sound like some kid at the back of the bus blaring some shitty tune
through a you know one inch speaker I don't want to sound like a tin can
I don't want to sound like a little tiny thing it needs to have some kind of like
resemblance of reality and that's what we're going for so stick with me I've
got a few ideas let me know in the comments below if you think those ideas
are wack or if you have any better ideas cuz like
hive mind it man, you guys have good ideas too so let me know
all right first thing we have we have our co2 cannister another thing is here
I have my mechanical valve this is a spinning mechanical valve I have to spin
this red knob here to open and close the valve it doesn't have to move much but
it definitely needs a lot of power to close so that's another thing I have to
worry about I don't even know how many
blow-off valve cycles I'll get out of one of these these cartridges but I'm
hoping like a 10 minute maybe a battery pack of drifting would be worth it
these are pretty cheap I think they're like a buck maybe 2 bucks for a co2
cartridge the first thing I'm gonna do is I got to figure out if this needs to
be reduced we may need to create some kind of gear reduction we may need to
have the servo spin more times than this valve so that way we get more distance
rotation here to close this to close this valve with more fine precision as
well as we increase the torque so this that will also give us more power to
open and close that valve which might also be important this is kind of the
idea what I may end up doing is flip this
around like this and then create a larger gear on the valve and a small
gear on the servo, let's proof of concept this thing shall we.
ready? it definitely makes a "psh" don't have to
DUDE, you don't have to make the psh sound. it already does that. we still haven't talked about how to make
it sound like there's no volume if we trumpet this somehow we can shape the
sound so I'm gonna worry about that later but that kind of sounds great
poof of concept totally worked we are gonna need more torque think I gotta
build the gear and I'm gonna stack them okay so that's the next step
alright so I basically have to copy this shape
it does great. oh my god I love this machine.
alright so this is cool this works it works it's a valve it takes about maybe
an eighth of a turn to pop open the valve
I'm assuming it's some kind of like worm gear here and this valve pushes a ton of
air through this pipe so the first problem I'm seeing is that I'm using way
too much air every time I open this valve I need to restrict it I need it so
that the air I'm not bleeding a ton of air every time I open the valve. another
thing is what makes a blow-off valve sound like a blow-off valve is the fact
that there's a big compressor that's just blowing air through the system at
all times so you're getting this whoosh of air and it's just a lot of volume of
air and it just continues for quite some time so that's not what this is giving
me this is giving me a very like nitrous purge sound which makes sense because
that's basically what the nitrous purge does is it just like burps the the
solenoid valve makes sure that the system is primed and has gas right at
the valve so that's basically what this which is cool like if this just becomes
like a nitrous sound then I'm all for it but I really wanted to sound like the
choo-choo of a turbo car
so yeah this is just one of three other projects I'm gonna do for practical
sound for scale drift the other one I want to do is want to do the the RPM
sound the engine sound using another motor and another esc controlled by an
Arduino so that it can fluctuate the rpm to sound like you can go through the
gears or you can hold third gear you know like you would be if you were
drifting but when you stop you can go down in a second for example something
like that would be really cool because it would be really cool to be able to
rolling anti-lag with the blow-off valve and bounce the live limiter and it would
also be cool as another practical effect to have a backfire kit and just build a
proper backfire kit out of a BBQ igniter that would also be super cool
as you all know I'm giving away a set of 3d printed seats every episode of kpop
RC leave me a comment below make me laugh and maybe you'll get a set this
episode's winner is Eric flack jr. yo your seats are on their way
anyway until I can order more of these that's it for this project but yeah it
seems pretty sweet really cool that my new 3d printer can print such amazing
gears I didn't think you could ever do this this is really cool this like opens
up a whole other world you know to be to be able to do you can just slow moving
gears like this is great like I designed these in Sketchup in like 20 minutes
also visit scale Sciences YouTube channel where we talk a little bit more
about 3d printing RC drift and this blow-off valve concept don't forget to
give scale science a sub and also don't forget to tell them kpop Sencha
leave me a comment below if you want to win some Recaro seats. there's a 110 scale 3d
printed Recaros they would probably look to open your project or your skill
brawler whatever or even on your dashboard of your car leave me a comment
i'll pick a i'll pick one that i think it's funny or cool and and i'll ship
these out stay safe they pop out for