Boosting Engines for Cheap! | Engine Masters | MotorTrend

this is what's called a roots supercharger the design where you have two rotors in here that spin together it's actually a positive displacement compressor this is 174 cubic inches every time it rotates all the way around it shoves that much air into the engine you can see how they roll around here and are sealed with teflon the whole reason any supercharger including a turbo makes more power with boost is because you're cramming more air into the engine when you have more air you can burn more fuel and with more fuel you get more power plop the carburetor on let's check it out probably prop the carburetor on in the right direction i don't have any uh people are always asking us why aren't we using efi you know what a lot of it is is we've got to crank these videos out really quickly and this way we don't have to hook up a bunch of sensors or do any wiring or create a tune up for anything this is just simpler for initial fire up and running and a wide open throttle tends to make kind of the same horsepower either way and also for this particular test we're talking entry-level superchargers and entry-level guys often don't have efi and this is rudimentary technology let's face it and let's see if i can pour this as good as fry burger whoa damn i'll quit before i make a mess if you're seeing some smoke out there in the room that is just a little oil leak that we've got coming out of the flywheel bolts in the back so don't worry about it okay oh 5.6 5.9 pounds of boost but at peak power yeah that's about it five and a half pounds of boost neighborhood of let's see what kind of power we made with the wine blower at five and a half pounds of boost we made 473 pound feet of torque and 522 horsepower here's the problem though 520 horsepower is not a number you want to throw out when you have a blown small block but because the boost is going through the carburetor and also through the vent tubes for the float bowls which are holding the fuel and the fuel is coming in from the fuel pump you have to have what's called a boost reference fuel system because imagine seven psi fuel going into the bowl and seven psi of boost going into the vent tube seven psi working against seven psi is zero psi you would get no fuel flow so you need a regulator that can reference boost from the hat and step up the fuel flow in direct proportion to the boost in english you want seven psi more fuel pressure than boost at all times right exactly and if you reference the boost you just add seven to it and you'll always have plenty of fuel what would i do without you i think i'd get out my calculator really you can be replaced by an iphone oh man this is gonna be our first test with the paxton supercharger we tried to make it run with that out of the box holley ultra xp carburetor and it just basically wouldn't run we're not exactly sure why it was either too rich or too lean it was just misfiring it was struggling it's like hit or miss on whether a carburetor is going to work right out of the box with one of these deals or not it can be made to work i'm confident but we happen to have a carburetor in the cabinet that we already know kind of works well with these blow through stuff and so we opted to take the easy road and put the other carburetor on do you think this one works stevo yeah i'm very confident this carburetor is a holley 850 double pumper but it's been worked over by a company called csu it has annular boosters and a bunch of other trickery to make it work specifically with a blow through application like this is it going to save us yeah yeah we're good right now okay belt slip yeah you could really see him wagging yeah the long side every time 6.75 here's what just happened final run we didn't have any belt slip and that junk made 573 pound-feet of torque which is sort of just stuff because it made 675 horsepower this is a pro charger centrifugal supercharger now i've never run the procharger brand before but i am impressed so far the quality on this thing is nice these are made in usa they've got a billet impeller they have a billet gear drive setup and the company makes blowers all the way from you know a tiny 850 horsepower capable unit all the way to 3500 horsepower which is cool the particular model that they asked us to run today is an f1 a94 it's got a nine inch volute it's nice and compact it can flow 1625 cfm it can make 1200 horsepower it's a self-contained unit meaning that it does not need oil plumbed to it from the engine that's a big deal to me i hate having to run a pressure line and the return into your oil pan poking a hole in it and all that stuff the other thing that is good about having self-contained oiling is that it stays cooler but the part i like is that when we scatter this engine we're not gonna be sending oil full of shrapnel from the engine through the supercharger and killing it at the same time one thing about this unit is that it has a 5.4 to one step up ratio what that means is for every one turn of this pulley that's driven by the belt we are turning the impeller 5.4 times see this unit is capable of turning 74 000 rpm yeah that's a big deal we're probably not going to be spinning it that fast in this particular test now we are going to run this with a blow through carburetor you need a special carburetor to do that efi is just a smarter way to go though you can pull this off and if you're going to try i recommend one of these carburetors modified by a shop called csu this is an 850 holly they've set it up with their magic just for blow through applications westeck has had a lot of luck with this unit right here and so that's what we're going to run today and when we do we're going to start small and go big here's how the larger the pulley that you put on the supercharger the slower you turn the supercharger and so the less boost you make so we're gonna start mild we're gonna find out how many smaller pulleys we can put on before we send this 350 to kingdom come here we go wow wow get out of here what we just saw there our final with the 3.7 inch pulley and 18 pounds of boost with a little bit of belt slip is 653 pound-feet of torque at 5800 rpm and 733 horsepower at 6000 rpm i have complete confidence in this motor now i can go eight hours with that rocket 118 it's in reasonable timing and good gas and all those things that a lot of guys don't do while you guys are celebrating we have one more pulley that we can blow it up i know and we've got to make that belt like a piano string small pulley piano string seven eight and then two more degrees of timing oh no yeah you just you just want to kill it don't you let's put the pulley i thought we were gonna give it a reprieve after seven five oh yeah that was this morning yeah great yeah mic drop the belt still slipped when i saw 25 psi did you 765 horsepower wow didn't make 700 pound feet though made 6.93 that is the comparison of naturally aspirated power to our boosted power that's insanity [Music] [Applause] [Music] sweet yep okay look at that 562 pound-feet of torque and 545.9 horsepower so picked up 210 horsepower thing is it's less than 10 pounds of boost on a stock engine and we're not trying to blow the crank out of it we're not trying to make a whole bunch of boost this is a combination that would be a riot to drive it like our little pickup truck or something like that yeah i mean we remember what it made stock i mean it was 330 horsepower that's a huge difference 60 percent that's so simple why wouldn't you do this why have you resisted this your whole life originally it was cost back in the day you know you just didn't have ready availability of turbos and you didn't have efi yeah and even if we did you would have rejected it on philosophical grounds and well these early efi systems weren't that good like the ford muscle truck and it was just unworkable practically yeah whereas it didn't blow some carburetors back then either right and you know there's a couple of builders but they weren't very prevalent now the next thing we're going to do is pull the turbo off of it and upgrade the thing with typical naturally aspirated hop-ups then we'll see the difference in power curves between stock with boost versus hopped up without boost i can only wait for the results i would predict somewhere in between those two curves in our quest for giant power we've changed the spring in the wastegate and we're looking at like 18 pounds of boost now steve's been tuning it up hasn't gone all the way to 7000 rpm yet so we're on our way but i am now are you this is the one okay here we go our final glory run [Music] [Applause] [Music] 950 plus horsepower i'm gonna be the voice of reason at this point and go that's good enough look at the heat in that uh crossover it's glowing yeah i think we're at the back pressure limit of what these manifolds and that crossover want to do i'm pretty impressed that we got to 950 and that's good stuff yep 956 horsepower at 6 900 rpm and 774 and a half pound feet of torque and what was the boost 18 and a half that springs right at 18. so that's a 18-pound spring in the wastegate really making right at 18 psi right at the top so now we'll compare it with our conservative test okay let's have a look oh why would you ever run on bump gas and you can put stack boost into it and make big power but again this thing is 325 cubic inches and we made 950 horsepower i'm doing the math and it's it's you know i hate it now i see why the turbo thing has caught on so hard in the last three horsepower cubic engines why i thought you were gonna stand up here and tell me all the reasons why the turbo was way too complicated and not worth the power well look i'm not even just gonna discuss this turbo by itself the whole 5.3 i loathe the five three oh you did it was the 307 chevy of ls motors to you know a small bore right it's not a five seven it's not a six liter so i mean just the motor it proved it's worth even in any cheapest ones you can get these anywhere look how much power it made bone stock with the turbo but not only that look how much power it can handle yeah i know and it had more to give i know but the point is built versus boost versus both which way do you go well i mean that's no-brainer boost wins both both yeah i mean you will have that hot pig under the hood and that's kind of a problem but if you can tuck it in the right place i'm really good at fabricating tubing and pipe and laying it out masterfully really so in a car that i set up it'd be great so we did convert you with this episode that's what i'm saying i'm a changed man wow yeah dinosaur reborn that doesn't happen on every episode what do you mean dinosaur oh i'm progressive and with the times when it comes to engine stuff

Channel: MotorTrend Channel

Views: 562,048

Rating: 4.8984866 out of 5

Keywords: motortrend, motor trend, motor trend channel, motortrend on deman, motortrend full episodes, engine masters, engines, roadkill, car engines, engine boost, boost, short block engine, engine tips, supercharger, how to supercharge an engine, dyno testing

Id: qjbDSiuSkHM

Length: 13min 45sec (825 seconds)

Published: Tue Aug 11 2020