Turbo Your Car - Choosing a Turbo

so you want to turbo your car classic you want to make a lot of cool noises you want to make some power you want to make a bunch of dudes think you're cool and you want to be a boost creep but there's so much to it it can be so overwhelming how do you pick a turbo how do you know anything is going to work together how do you keep your engine from blowing up how do you keep stuff cool and most importantly how do you pick a turbo well that's what we're doing today baby it's part three of the six part turbo saga today we're talking turbos a big holiday thank you to ridge wallets for sponsoring this episode anyone else feel like wallets are just becoming more like suitcases nowadays oh my back oh for sponsoring this episode anyone else feeling dang on my gift receipts future jokes no one it's 20 20. no one needs gift for seats and if you try to put that in your back pocket you're going to break your dang back you won't even make it home for christmas let alone hear santa's sleigh santa slate people really did like that episode of up to speed yes they did there's no reason to fact check that now why don't you take this the ridge wallet doesn't fold or awkwardly bulge in your pockets it's about carrying less while always having exactly what you need this is great it's a bummer people have to wait till the future to get one oh contrera nolan the future's here all you gotta do is go to ridge.com donut and use code donut to save ten percent but you gotta hurry because time is of the essence wow future job you've really saved us from a lot of painful scenarios you deserve a break maybe i do nolan maybe i do thanks ridge wallet all right so this is the kit that we have it's the cx racing kit last week we installed the turbo manifold and we talked about downpipes which means this week we're ready for the freaking turbo itself which is super exciting but it's also a little daunting because there's a lot of stuff that goes into these and a lot of stuff to talk about what are all these different numbers and sizes and measurements well buckle up babies because we're going to talk about it today by the end of this episode we're going to have a turbo bolted to the miata so get ready i'm excited here it is the turbo we've all been waiting for so we're gonna get into it but first let's talk just briefly about how a turbo works two sides of the turbo the hot side and the cold side the hot side is the side that deals with the exhaust and the cold side is the side that deals with the fresh air being sucked in from the atmosphere and then crammed into your engine exhaust gases go through the turbine inlet here they spin your little fan in there and then the exhaust comes out here and back down the rest of your exhaust out your tailpipe since these fan blades these wheels are mounted on a common shaft when your exhaust spins the hot side the cold side is also spun and that sucks air in from the atmosphere pressurizes it and forces it into your engine so that's really in short how a turbo works it uses your exhaust to spin some fans to suck in and pressurize air and force it into your engine then over here we've got our wastegate so the wastegate is basically the system that we use on a turbo to control boost and this one is built to operate at eight psi so basically what happens we will connect our wastegate to vacuum pressures and then when we hit eight psi of boost pressure the spring in this wastegate will be overcome it'll force this arm to actuate and open and it opens a little flap in here which allows exhaust gases to bypass the turbo effectively lowering boost pressure or controlling boost pressure so now that we understand how a wastegate works and what it's doing let's go ahead and take the turbine and the compressor housings off so we can get a better look at the fan blades and what the heck's going on in there okay so when we're talking about turbo wheels like this and this is our compressor wheel there are basically two sides there's the inducer and the exducer the inducer is always going to be where the air comes in and the exducer is going to be where the air exits this turbo from cx racing might be fine but the fact is we don't have that much information that's one of the big issues with cheaper quality parts you don't necessarily get all the information that you get with a high quality part so we're going to go ahead and measure our fan blades here we're going to measure the inducer and the exducer we've got about and a half millimeters there now let's move on to measuring the exducer side of the compressor wheel and that's where the air exits we got about 70 millimeters so now let's yank off the turbine housing and get some measurements off of that wheel [Applause] and there's our turbine wheel and our turbine housing so on the turbine wheel the inducer and exducer are actually opposite of the compressor wheel again it's all about where the air or the exhaust gas comes in and where it exits and on the turbine side it comes in at the big part of the blade and it exits at the small part of the blade so we're gonna measure our inducer and exducer okay about 65 okay what do you think so now we've taken the measurements from our compressor and turbine wheels on the inducer and exducer side so that means we have four measurements total across both of our blades but we can boil those four measurements down into two and those two measurements will kind of each characterize one of our wheels and that's what's called trim you may have heard of turbo trim before and what that is is basically describing one of your wheels so we'll say our compressor wheel here it describes the ratio of the inducer to the exducer so the higher the trim number generally speaking the more air a wheel will flow all right so now that we understand a bit about our compressor and turbine wheels how to measure them what trim is and what the size of your wheels means let's talk about the housings they sit in because they're pretty important these are our housings this is our compressor housing and this is our turbine housing and the way these are measured is another measurement that you may have heard of when talking about turbo stuff ar which stands for area over radius now the ar rating of a housing is basically going to be related to its ability to flow we really don't pay too much attention to our compressor housings but a turbine housing is absolutely critical for sizing the right turbo to your engine basically the measurement of the turbine housing relates to how much exhaust gas can flow through it which is super important in terms of making power the way you want to make power we don't really need to know what the measurement is what we need to know is that the larger an ar number for a housing the more it can flow in terms of exhaust on the turbine side or to some extent the compressor housing but if you use a large turbine housing that also will create lag it takes time to spool up a smaller turbine housing will create a quicker spool a more responsive turbo but since it can't flow as much exhaust it can choke your engine out at higher rpms when massive amounts of exhausts are trying to flow through this housing so that's kind of the trade-off but getting it right will make sure you have a turbo that does exactly what you want whether that's massive peak horsepower and you're okay with some lag or if that's a really responsive turbo at the cost of peak horsepower now my preference generally speaking especially for a street car like the old miata is to have a responsive turbo that's fun to drive that has good low end that doesn't necessarily make max peak horsepower because that's really not where i spend most of my time on the streets you know what i mean okay let's talk about compressor maps briefly it's one of the best tools to use to size a turbo to your engine it basically gives you a plain look at how much air a turbo can flow and we got to talk about some fundamentals real quick before we look at a compressor map uh it's all about airflow horsepower is about airflow the more air you can flow through an engine the more horsepower you can make and obviously that's what turbos are here for they help us increase airflow but turbos come in all sorts of different sizes and they come in different airflows as such but since horsepower is all about airflow that's how turbos can be rated in horsepower so when you're shopping for a turbo you want to make sure that the displacement listed by the manufacturer for the engine and the horsepower range for that turbo match your goals all right so here is our compressor map so let's talk about what we're looking at here first off the x-axis corrected airflow in pounds per minute now roughly speaking one pound of airflow per minute can translate to about 10 horsepower at the crank so here where we see 20 pounds of air flow per minute we can think of that as about 200 horsepower if you want to make 500 horsepower then you need to find a turbo that can handily flow 50 pounds per minute now on the miata my power goals are about 225 wheel horsepower so that means i need to make about 270 at the crank so that means i'm looking for a turbo that can efficiently flow around 27 to 30 pounds of air per minute to meet my power goals now the y-axis is our pressure ratio this is this is kind of boost but it's a little bit different in that it's a pressure ratio it's just the ratio of the pressure in front of the compressor like in the atmosphere versus on the other side of the compressor the boost side that's cramming air into your engine now to understand that we have to understand that the atmosphere that we are in all the time is about 14.7 psi so in the case of the miata and the turbo that i'm gonna be running we're gonna start at eight pounds of boost that's what it's internally wastegated for and we'll turn that up in the future but for right now we're going with eight pounds of boost basically we're gonna do is add the boost that we're gonna be making with our turbo to atmospheric air and then the ratio is that number versus our atmospheric pressure so that's where we're going to land on our pressure ratio we're running a pressure ratio of 1 to 1.55 then we can determine whether or not that puts our turbo in an efficient area alright so let's see where this lands at about 27 pounds of air flow per minute at about 1.55 on our pressure ratio that drops us right in over here so basically what we're looking at here in the graph this whole series of ovals these are called efficiency islands so we want to land in these efficiency islands to make sure that the turbo is operating in an efficient range if it's not then it's just going to be creating a bunch of heat and not power so if we want to make the most power we want to make sure we land our turbo in an efficient area we can see that we do land in these efficiency islands i think we're in this 65 range now this has been a very brief look at compressor maps if you want to go way deeper into them and learn a lot more about compressor maps you got to go check out my dude greg peters at the car passion channel he does a whole video all about compressor maps on a turbo miata it's really great now with that all said when you're actually shopping for a turbo what you'll find is that pretty much all turbo manufacturers use a totally different naming convention so the numbers that are attached to the name of a turbo for garrett or borg warner precision they're all going to be a little bit different but they all in some way relate to the measurements that we've talked about here today so all you got to do is go to their spec sheet and figure out what the numbers are actually related to so let's get into it let's start getting our hands dirty and actually get a turbo mounted up to this nasty little bit well didn't take long for me to run into my first hiccup the first thing i wanted to do with getting the turbo installed was get oil pressure to the turbo get that figured out and you know honestly i went into it thinking no big deal because one of the nice things about the 1994 mazda miata is that on the side of the block right under the exhaust area we've got a coolant port here and an oil port but of course the cx-racing kit doesn't take that port into account so i don't have anything that's just going to plug right into there so i need to go from that in there to my oil feed line in which is this npt thread so hopefully i can find a pretty chill little adapter to go from that to that but i guess i got to do some online shopping but for right now i'm going to get the turbo manifold back on and then we'll work on the oil return because i know i can make that work oh and the hits keep coming okay so we had our little snafu with the oil pressure fitting that i'm going to need to find so if you're dad no big deal we'll just keep rolling we'll just move on to the oil return you see with any turbo system you need to get oil to the turbo and then you need to return it to your oil sump so in a situation like this where we don't have an oil return for a turbo already our turbo kit the cx racing kit came with this little fitting basically the idea is that we drill a hole in the side of our oil pan then this goes in it and then these two washers sandwich help it not leak tighten that down from the inside and then you've got to return the hose can go from your turbo right into this and then this just sticks off the side of your oil pan so i figured ah no big deal just yank the oil pan off and put this in what i wasn't thinking of is that to take the oil pan out of a miata you have to lift the engine and drop the subframe so i've got a little more work ahead of me than i was anticipating we're gonna have to get the oil pan out to get this installed and there's just no two ways about it i'm just gonna have to do it i'll see you tomorrow [Music] hey friend i know where you're at you forgot to get a gift for the donut fan in your life and it's too late for anything to be shipped well you're in luck because donut media gift cards are a thing and you can get them in some phenomenal increments i'm talking twenty five dollars fifty dollars seventy five 100 150 and if you want to do something crazy like 7 500 give me a call and we'll work something out the donut media gift cards are 100 digital they don't rely on the old-school guy on a horse delivering things which is how i assume things still get to people and each of them are designed after an 80s credit card which is a genius idea that i came up with in literally three seconds so head on over to donutmedia.com and pick up your perfect stocking stuffer today [Music] okay so we do finally have the oil pan out and we got our oil return installed on the oil pan now this location for the oil return will work in terms of where everything's at up here and my routing from the turbo to the oil pan i think i hope that was the plan that's why i put it here but the big question is and one of the problems in my opinion of this return style that has a nut on the inside as opposed to a threaded style is that now there's this big nut on the inside so i am going to put the oil pan on without any sealer and spin the engine by hand just to make sure this doesn't hit the crankshaft or the bottom of the connecting rods or anything because if it does that's a pretty big problem and i'll have to move this somewhere else i didn't really think about that before i did this but hey here we are now the good news is i do have a backup oil pan uh should i need one so it'll be okay all right so we just got done checking clearance of our oil return and the good news is we're good uh it'll be fine there i do need to make a little hole in the windage tray that drops in here so it doesn't interfere with that but it looks like this return spot will work exquisite okay so now that means we're pretty much ready to put some sealant on this oil pan and put it back up in and put the sub frame up in and get back to the turbo all right we've got the oil return line finally installed in the oil pan and it's ready to be plumbed up so now i'm just putting the turbo onto the turbo manifold which is huge news very exciting and then once we've got it bolted to the manifold we will plumb up our return line making big steps baby that was the sound of piston number four coming out the side the best thing about problems is figuring out how to solve them uh well sometimes getting a turbo hardware into place is tough because well it leaves you in kind of tight spots trying to get hardware in and then trying to get a wrench on that hardware to tighten it so uh like on this specific uh nut in there i can't get a wrench in there so i'm just tightening it from below and i'm using the screwdriver to keep the nut from spinning so this is my screwdriver wrench pretty sweet wrench all right the turbo is tight that is great news so now with it in place we're ready to trim up our oil return line and get it attached to the turbo so to do this basically the big thing you want to make sure of is that there are no hard turns or bends or kinks in your return line so that obviously comes into play when you're choosing where to put it on your oil pan but it also comes into play when you're routing the hosing so i've got it going down through the lower coolant hose and a couple other things down here and it honestly looks really good it's a nice straight shot to the nipple down the oil pan so now i'm just going to trim it so we got a nice straight return line uh okay so another thing to make sure of when you're setting up your turbo and all your lines is that the oil feed and especially the oil return stay pretty well vertical as far as their orientation is concerned so you can rotate the center housing the rotating assembly in there any which way you like but if you rotate it too far either way it's going to have a hard time draining the oil and that's not what you want if your turbo has a hard time draining oil or oil gets backed up it'll start coming out the seals start making smoke and just not be a good time so you want to make sure that your oil drain is pretty close to vertical i think they say like 15 degrees either way is okay but i just try to keep it straight up and down [Music] okay so the turbo's in place and our oil return line is looking nice it's nicely plumbed up so now i think it's time to see if this down pipe fits we talked about it last week but now with the turbo in place we can actually install it so let's uh see how it goes well that's good news i mean hey it's it's in the right ballpark now so these are v-band clamps these are great uh exhaust unions i guess you could call them so we just use this little clamp all right so the downpipe is roughly in place the great news is that it seems to fit pretty well it's uh it's in there where it belongs uh it is pretty close to some stuff like our coolant line for the heater core we do have a little air gap now but that said this downpipe is going to be super hot and i really should and eventually will put some exhaust wrap on it to try to contain some of this heat same thing with the turbo manifold absolutely not a bad idea to exhaust wrap that to try to contain the heat uh you know keep it in your turbo rather than in your engine bay but for now i think it's going to be okay now i am ready to go underneath and see if this thing fits up so this is the intermediate pipe that goes from the down pipe to our stock exhaust yeah pretty close it's got a little flex pipe here this is going to be just fine all right well this is great i just got to get the v-band clamp on here get some nuts on this end and wow the hot side is done the manifold's on the turbo's on it's plumbed up and now we've got a downpipe and intermediate pipe connecting to the exhaust that goes all the way out the back it's really shaping up all right so we got a turbo installed on this miata and that's awesome but before we go let's talk about one other thing one of my favorite combinations of words in the english language and in a set of words that just popped into my head because i forgot to bring it up earlier shaft play so depending on whether or not you got a journal bearing turbo or a ball bearing turbo kind of will dictate how shaft play should feel so first off you've got the up and down shaft play or uh radial shaft play so that's trying to wiggle it up and down and it's uh in its little home in there and then there's end play or axial play so trying to push the shaft this way as opposed to this way so because this shaft rides on a thin film of oil there's always going to be a little bit of up and down play on the shaft of a journal bearing turbo this one's brand new and you can feel a little bit of play now that's totally normal when the engine's running there's oil pressure in there that stiffens that puppy right up the only problem is you can't really get your hand in there to wiggle it when it's running now if this were a ball bearing turbo and there were that much up and down play that would be a problem a ball bearing turbo all the time should have very little up and down play now what you really want to pay attention to on a journal bearing turbo and a ball bearing turbo is end play so if you can move the shaft in and out this way you got a problem luckily we can't so that's what you're looking for when you're talking about shaft play there's up and down and there's end to end so now that i've gotten away with saying shaft play on youtube a few times i think that's really going to do it for this week and what a week it's been there is finally a friggin turbo on the miata i know you guys have been excited for this day and i have too and it's finally here we've got the engine compression tested and leaked down tested we did the manifold we did the turbo and now the downpipe's on as well so next week you got to check back because we're going to get into the cold side we're going to do all the intercooler piping the intercooler itself and the blow off valve so don't forget to follow me at zac job and follow donut donut media and i'll see you guys here next week for some blow off valve noises which no i can't say that because we're not going to get noises next week either what no that doesn't work don't use that no

Channel: Donut Media

Views: 2,113,196

Rating: 4.9665303 out of 5

Keywords: Mazda, Miata, Mazda Miata, NA Miata, turbo miata, turbo, turbo manifold, exhaust manifold, turbo exhaust manifold, diy turbo, cx racing turbo, cx racing, cx racing turbo miata, turbo kit, how to turbo, AR turbo, Garrett turbo, borgwarner turbo, turbo compressor, turbo trim, turbo turbine, compressor ratio, Donut Media, Cars, Automotive, Money Pit, automotive history, Donut, Donut Miata, car build, car mods, Zach Jobe

Id: 7SOnsbq_qjU

Length: 22min 7sec (1327 seconds)

Published: Wed Dec 16 2020