Boost creep is a phenomenon that can occur in turbocharged engines, where the boost pressure increases as the engine RPMs rise, due to various factors such as turbocharger design, intercooler efficiency, and fueling. In this test, we're looking at how our engine responds with different boost levels, first with the cat (catalytic converter) in place and then without it.
Now, what we're looking at here is boost. The dotted blue line that's our run with the cat, and you can see boost comes up and red stays pretty steady at where we want it. But the magenta line is with the test pipe. And you can see it comes up and it starts to flatten out like we're controlling it, but as RPMs come up and our exhaust is flowing so well with our new test pipe that the internal waste gate on this turbo is overwhelmed basically. And isn't able to bleed off enough pressure to keep our boost at the level we want. We're telling it to completely dump boost at that point. It doesn't matter. It's just boosting.
As we're so high in the RPMs and that tiny little internal waste gate is just overwhelmed. So we're kind of stuck with this. I mean, we're making like 260 horsepower with the test pipe because we can't keep boosts down to where we want it. So that's kind of cool. I mean, we made like 30 horsepower but we're also apparently at the limit of our waste gate setup and as such our turbo setup. So we might have changed turbos in the not too distant future if we wanna change the way things are going.
Okay. So with our boost creep issues explained, I still wanna try to make this test a little bit more apples to apples. So I just put the cat back on and now what we're gonna do is, try to match that boost creep with our tuneso that we try to put the same amount of boost through the cat on purpose. So then we can at least see how much power we make at those boost levels with the cat in place versus those boost levels with the test pipe. Even though the test by boost levels are on accident, makes sense? I hope so.
All right. So we just got done retesting with the cat. And we're looking at our boost map here again and you can see our original boost line that we were kind of chasing, that magenta line is in there somewhere, just buried by all these other boost lines because we did a really good job of mimicking that boost, that boost creep that we were having.
So once we did that and we retested the cat, the numbers that we got are as follows, we have 252.8 horsepower on average with the cat and 210.1 foot pounds of torque on average. Then with the test pipe, we managed 257.7 horsepower on average and 217.2 foot pounds of torque on average. That means we picked up 4.9 horsepower and 7.1 foot pounds of torque with the test pipe. Not too shabby. It's certainly not those 30 horsepower that we were seeing in difference.
But with our boost creep issues taken into account, I think this is a pretty valid test as far as tests go. Well, we sort of did it. We made a test pipe. That was pretty cool. We put it on the Miata and we definitely made way more power with it. Now I'm not too happy with the way that we made the power. I think we've got some issues like we talked about. So I'm gonna have to address those issues in the future.
But for now, we are making 260 horsepower. So I've got some more work to do on the Miata. Now, if you also like working on stuff and like the types of videos where we work on stuff, then you gotta go check out yesterday's bumper to bumper where Jeremiah goes over and insane 2000 horsepower Altima. They talk about 3D printing body panels. They talk about how the heck it even makes sense to basically delete the whole chassis and replace it all with tubes. And they'll divulge a little secret. Which seat is the most fun to ride in, in a drift car. Hint, it's not the front seat.
So go watch that bumper to bumper. You will not regret it. You just gotta click right here. Oh, and also don't forget, we've got an underground, the Donut underground. And one of the perks which ends tomorrow is that we'll send you a free sticker every three months, if you're a member. But you gotta get signed up by tomorrow to take advantage of the free stickers. For more information about Donut underground just click the join button below and I'll see you in the underground.
And also with all that said, I'll see you guys next Wednesday. Don't forget to follow me on Instagram @Zachjobe and I will catch you cool cats, in the next video.
WEBVTTKind: captionsLanguage: en- Okay. So the only remaining stock parton the Miata's exhaust isthe catalytic converter.Now the catalytic converters are great forreducing unwanted emissionsand burning off the toxic pollutantsthat come out of your exhaust.And I can really honestlyget down with that.But in the case of the Miata,I'm looking for unbridled horsepower.And the catalytic converteris kind of a restriction, or is it?How much is it restrictingmy exhaust flow?That's what we're gonna find out today.We're gonna make a straightpipe to replace the cat.Then we're gonna goback to the dyno to seehow many ponies thatstraight pipe frees up.We got a welder.(upbeat music)Thanks to Honeygain forsponsoring today's video.Honeygain is an appthat will make you moneyjust by sharing your internet connection.No effort required.Simply install honeygain on your Android,MacOS, Linux or Windowsdevices, and that's it.Consider it the Airbnb for your internetand with no personal data gatheringor required device storageit's a hundred percent safe.Honeygain uses your internet connectionto get various bits of info from the weblike prices for flights or shoes.It's a way for best dealsites to compare pricesfrom different regions,almost like the Google ofweb monitoring for companies.And while they're doing thatyou're getting paid for simplysharing your connection.Now don't expect to earn millions butit could cover your Netflixsubscription every month.Nice. I just made 20 bucks.So what are you waiting for?Sign up by clicking the linkin the description below.And if you use promo code 'donut'you'll get $5 added toyour honeygain account.Now let's get back to Money Pit.(gentle music)So this is what the insideof a catalytic converter looks like.It's basically a honeycomb patterncoded in some rare earth metals likePalladium, Platinum and Rhodium.So as you force hot exhaust gasthrough your catalytic converterit makes a lot ofchemical reactions happenand basically cleans your exhaust.A bunch of harmful pollutantsthat would come out of yourtailpipe are scrubbed offin the catalytic converter,and the only things thatcome out in your tailpipefor the most part are harmless.So the goal today is to replacethis catalytic converterwith a straight pipeor maybe you've heard it calledtest pipe before. Same thing.To do that, that means we'regonna have to make that.So let's go see what we're working withand come up with a game plan.This is aluminium steel.This is gonna be really easyto work with, easy to weldmaybe rust over time, especiallythese mild steel flanges.But it's gonna be relatively easy to make,and this is also the cheapestmaterials that we can get.So the first thing I'm gonna do istry to figure out theangles of these flangeson the pipe in terms of degrees.We got 86.3. So we basicallygot about four degreesof angle from straight vertical.So here we've got 82.1so that's about eightdegrees off of vertical.And now we know that we are aiming foreight degrees this way andabout four degrees this way.These are the flanges that I got.She is flat.She is mild steel and she is cheap.And she's for a two and ahalf inch pipe which this is.Now you can see there'sa little bit of a gap.What that means is thatyou can go like this.So I think we're gonna be ableto get enough angle out of itwithout really doing too much.The trick is gonna be settingthat angle before I weld it.All right. So there were plenty of waysto cut exhaust tubing.The other week when we didNolan's exhaust cutoutswe cut exhaust pipes by hand.You could also use areciprocating saw like a sawzallor a cutoff wheel.But to make nice repeatable cutsa band saw really iswhat the doctor ordered.Now, this is a pretty cheapone, about as cheap as they get.Think they run from about275 bucks these days.Basically what I'm gonna do iscut a little sliver off the end,but at an angle at about eight degreeslet's get to cutting.Okay. So bandsaws like thisgenerally have some sort tension controlso that you can set the tensionand then you can walk away from the cutwhile it's happening.So, I've got her set.(bandsaw sreeching)Okay. So we've got our little wedgeabout four and a half degrees this wayand about seven degrees the other way.All right. So we're actuallyreally close to our first try.Now I just need to get theoverall length of this thingmeasured, cut, and then do thisagain for the other flange.(bandsaw screeching)Okay. Our pipe is ready to weld.So now we need to getour flange ready to weld.And the only thing we need to do thereis clean it up.whenever you're welding anythingit's really important to clean your metal.So I'm gonna clean the flange upand I'll clean the bottom ofthis pipe up a little bit.But I am gonna becareful with this becauseI don't wanna grind off toomuch of the aluminized coatingbecause that's what keeps it from rusting.All right. So we're ready to tack upthis flange to this pipe.So welding in and ofitself is a huge money pitand a very deep rabbit hole.So we're just gonna get started today.And we're just gonnafocus on MIG welding todaywhich again is in my opinion,the easiest version of weldingout there, anybody can do it.It is pretty simple.You just got to know a few basics.So that's what we're gonna cover today.The first thing we're gonnado is tack weld this pipeto this flange which means,we're just gonna put a few little piecesof weld just to hold this thing togetherso that we can test iton the car and make sure everything's goodbefore we fully weld all the way around.Okay. So the first thing we're gonna dois flip on the switch inthe back of the machineand then I'm gonna open my gas.So you might notice I havetwo gas tanks back here.That's because this machinedoes MIG and TIG weldingwhich use different gases.So this is my MIG tank.It's a mixture of 75% argonand 25% carbon dioxide.That's what you use generallyspeaking for MIG welding.So I'm just gonna open it up.And then we've got thispressure regulator herewhich meters the gasflow into your machine.I've got to set it about 30 CFMsor cubic feet per minute of gas.That's kind of standard-ishfor MIG weldingas far as I know.And this machine is super easy to set.It has an auto set feature.So you can just select the thicknessof material you're working onand then it will work out how much heatand how much wire speed do you use.Now on any MIG welder those arereally the two big settings,heat and wire speed.So I've got this selected at18 gauge thickness material.These numbers don't necessarily matter.Most welders will just have two knobswith random numbers on them.And it doesn't really matter.It's just the relationshipbetween the heatand the wire speed that you need to find.And it's really dictatedby what you're working onin terms of what kind of metalit is and how thick it is.So those are the basics you with me.Okay. So now this thing's ready.We're gonna attack our pipe into place.So the only thing we need to do apartfrom use our torch isground our work piece.So you can obviously groundto whatever you're working on,but especially if you're workingon a nice welding table like this,we can just ground to the table.Then we'll get our pipe setup and then put a few tacks on it.Let me find a welding helmet.(upbeat music)(welder crackling)Okay. Well, she's tacked on.Now. We can take this to the carand make sure things are looking right.Similarly, how we had to trim the bottomof the pipe up therebecause it would havestuck past the flange.We're gonna have to dothe same thing here.You can go like this.(blade buzzing)(upbeat music)Okay. So we've got ourtest pipe kind of in place.We've got our flange boltedto the rest of the exhaustand this looks like it's gonna work great.So now I gonna bring the welder down here.I'm gonna tack this flange into place.And then we're basically readyto go welder up all the way.It's always a good ideato disconnect the batteryof a car that you're gonna be welding on.If you're gonna beactually welding on car.Basically when you're weldingyou're using a lot of electricity.And if any of thatelectricity finds its wayinto your electrical system,it can do bad things.One of my buddies growing up actuallyshattered his rear windowwelding on a car becausehe left battery connected.(welder crackling)Okay. Now we got this thing tacked up.It's time to take it off the carand go weld it up and actuallytalk about how to weld.So as I go around thisI'm gonna be weldingin kind of a C pattern.capital C, capital C all the way around.Now, since our flange isa lot thicker materialthan the pipe itself,it's gonna be able to take a lot more heatbefore burning through.So what I'm gonna do is basicallyspend most of my time on theflange, plowing heat into that.And then I'll kind ofwalk up onto the pipejust for a minute, just for a sec.That's the method.Now, the other thing that'simportant is how far awayyou are from the piece with your torch.So you wanna be aboutthree eights of an inchhalf of an inch away from,from the surface of whatyou're welding with the torchand on something like this,where we've got this 90 degree jointI'm gonna be at about 45degrees in this direction.And then I'll kind of be atan angle in this direction.If this makes sense.Now there are two ways to go about it.You can lead the puddle where you'rekind of welding this wayand dragging your torch in front of it.Or you can push itwhere you're pushingthe torch from behind.It's kind of personal preference.I do both of those things.Depending on what I have to do,depending on what I'm working on.So once you understand kindof how to hold your torchand everything like that,do kind of a dry run whereyou don't actually weldbut you just confirmthat you can actually do,see like I'm hitting, Igot a little issue there.So, I should have this over my shoulder.Now I should have probablyjust done that from the start.But, I didn't, and I wouldn't haveif I didn't make that dry pass.So we'll do like this.And then we've got a niceclear path all the way around.I'll probably do this in liketwo or three different sections.So with that said, let's do it.(upbeat music)(welder crackling)All right. So the first sideof the test pipe's all welded upand it doesn't look terribleif I do say so myself.I'm gonna let that cool down for a minutejust as is, and then we'll flip it over,Weld the other side.(welder crackling)Okay. So Test pipe is completed.Now, the only thing we have left to dois go to the dyno and test itand see how much horsepower we gained.Let's go.We are back at my friendsat EF1 Motorsportsto get some dyno time from EF1 tuning.So the stock cat is on the car right now.So we're gonna put the car on the dynoand do some polls and see howmuch power we're making as is.And then we'll pull that offand install our test pipefor our straight pipe.And then we'll make some more pollsand see how much horsepowerthat straight pipe left us.(upbeat music)So that's three runswith the cat in place.And our average power is234 and a half horsepowerand 215.6 foot pounds of torque.So now we're gonna swapback to our test pipedo this again and see whatthe numbers provide us with.(upbeat music)Okay. So we are havingsome interesting resultsand I'm gonna try to explainwhat I think is happening here.We put the test pipe onand kind of lost theability to control boostsgetting a little bit of boost creep.Now, what we're looking at here is boost.Now the dotted blue linethat's our run with the cat,and you can see boost comes upand red stays prettysteady at where we want it.But the magenta lineis with the test pipe.And you can see it comes upand it starts to flatten outlike we're controlling it,but as RPMs come up and ourexhaust is flowing so wellwith our new test pipe thatthe internal waste gateon this turbo is overwhelmed basically.And isn't able to bleedoff enough pressureto keep our boost at the level we want.We're telling it to completelydump boost at that point.It doesn't matter. It's just boosting.As we're so high in the RPMsand that tiny little internal waste gateis just overwhelmed.So we're kind of stuck with this.I mean, we're making like 260horsepower with the test pipebecause we can't keep boostsdown to where we want it.So that's kind of cool.I mean, we made like 30horsepower, but we're alsoapparently at the limitsof our waste gate setupand as such our turbo setup.So we might have changed turbosin the not too distant future,if we wanna change theway things like are going.Okay. So with our boostcreep issues explainedI still wanna try to makethis test a little bitmore apples to apples.So I just put the cat back onand now what we're gonna do is,try to match that boostcreep with our tuneso that we try to putthe same amount of boostthrough the cat on purpose.So then we can at leastsee how much power we makeat those boost levelswith the cat in placeversus those boost levelswith the test pipe.Even though the test by boost levelsare on accident, make sense?I hope so.(upbeat music)All right. So we just gotdone retesting with the cat.And we're looking atour boost map here againand you can see our original boost linethat we were kind of chasing,that magenta line is in there somewhere,just buried by all these other boost linesbecause we did a really goodjob of mimicking that boost,that boost creep that we were having.So, once we did thatand we retested the catthe numbers that we got are as follows,we have 252.8 horsepoweron average with the catand 210.1 foot poundsof torque on average.Then with the test pipe,we managed 257.7 horsepower on averageand 217.2 foot poundsof torque on average.That means we picked up 4.9 horsepowerand 7.1 foot pounds oftorque with the test pipe.Not too shabby. Its certainlynot those 30 horsepowerthat we were seeing in difference.But with our boost creepissues taken into account,I think this, is a pretty valid testas far as tests go.well, we sort of did it.We made a test pipe.That was pretty cool.We put it on the Miataand we definitely madeway more power with it.Now I'm not too happy with theway that we made the power.I think we've got someissues like we talked about.So I'm gonna have to addressthose issues in the future.But for now we are making 260 horsepowers.So I've got some morework to do on the Miata.Now, if you also like working on stuffand like the types of videoswhere we work on stuff,then you gotta go check outyesterday's bumper to bumperwhere Jeremiah goes over andinsane 2000 horsepower Altima.They talk about 3D printing body panels.They talk about how theheck it even makes senseto basically delete the whole chassisand replace it all with tubes.And they'll divulge a little secret.Which seat is the most funto ride in, in a drift car.Hint, it's not the front seat.So go watch that bumper to bumper.You will not regret it.You just got to click right here.Oh, and also don't forget,we've got an underground,the Donut underground.And one of the perks which ends tomorrowis that we'll send you a freesticker every three months,if you're a member.But you got to get signed up by tomorrowto take advantage of the free stickers.For more informationabout Donut undergroundjust click the join button belowand I'll see you in the underground.And also with all that said,I'll see you guys next Wednesday.Don't forget to followme on Instagram @Zachjobeand I will catch you cool cats,in a week.Goodbye.
