Turbo vs Supercharger

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Could somebody, or many of you engine tech folks, hook it up with the pros and cons of turbos vs superchargers? I know people love the sound of a blow off valve, but i heard superchargers are all around better for low and top end power. i am here to be educated, dont make fun of me for not knowing these things
 

BioHazard the Reaper

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personally i think turbos are better. Super chargers take engine hp to run them, the belt runs of crank which eats horsepower to make horsepower.....turbos on the other hand are pretty much "free" horse power, and the blow off valve is an added bonus =)
 


RainyDaze

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Anyone may correct me on this, but I've heard that if you use a supercharger it is always running where as a turbo only kicks in at a certain rpm point, depending on whether you have a controller for it or not, I guess. I guess the question you should also ask yourself is whether the car will be a daily street driven car or just for the track/racing?? It might make a difference as to what you should get.

Anyway like I said anyone may correct me if I gave incorrect info.
 

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oh no...im asking just for educational purposes, im not planning on buying either any time soon. i just wanna know the difference for the sake of knowing
 


TurboZinc

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There is so much misinformation on the turbo vs supercharger debate its just unreal.
What kind of supercharger are you looking at? A centrifugal or roots style? The JRSC is a roots type, i believe, and the vortech is a centrifugal blower.
A roots type is great for low rpm boost, but lack the power up top. They aren't the most efficient means of compressing air, so as the boost increases it tends to heat the air considerably more than a centrifugal or turbo would.
A centrifugal blower does not create boost until higher in the rpm range. Max boost will most likely happen at max rpm. Boost is dependent on engine speed. This happens because the compressor wheel is spun by a pulley off the belt.
A turbocharger creates boost by using the spent exhaust gases to spin a turbine wheel attached to the compressor wheel, thereby spinning the compressor wheel. The boost is not dependent on engine speed, but rather on load. Full boost will come in at a much lower rpm than a centrifugal style blower, and it will hold that boost until redline, unlike a centrifugal blower.
I personally prefer a turbo, but they all have their pros and cons. A roots has great low end torque, but lacks top end power. The centrifugal has great top end power, but the boost at low rpm is non existant and the boost curve is linear to engine speed. A PROPERLY SIZED turbo has good low end response and will hold max boost all the way to redline. A turbo will usually be harder to install and will create more heat in the engine bay. A centrifugal blower or a roots type are probably the easiest to install and don't create much more heat in the engine bay.
 

BioHazard the Reaper

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i disagree on one part...that centrifigul dont creat engine heat....they still do becuase they have alot more friction going on in them, now true they do force "cool" air the intake brings in, they still do make alot of heat due the all the spinning parts involved....now the roots style is prolly the best supercharger to buy, although if for some reason youd want to use an intercooler on a supercharger, this style cannot be used with one, only the centrifugal...and as i said turbo, to me, is better, as its "free" hp...
 

TurboZinc

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I never said that a centrifugal blower would not create heat. It just doesn't create as much heat as a roots type blower. All types of forced induction will create heat.
Why again is the roots better than a centrifugal?
You make it sound as if running an intercooler on a cent. blower is pointless. In fact running an intercooler on a cent. blown car is just as helpful and important as running one on a turbocharged car.
A roots type blower can have an intercooler. It can't run an air to air intercooler, but it can run a water to air intercooler. Both the ford lightning and '03 cobras have water to air intercooler roots type blowers.
A turbo isn't "free hp". It still takes some horsepower away from the car to run. This is mainly in the form of backpressure instead of losses from spinning the compressor on the cent. blower, but it still loses a small amount of power.
 

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so all in all...what would you guys say is the best bang for your buck...including labor if we werent to do it ourselves
 

TurboZinc

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Originally posted by "Rice4Brains"

so all in all...what would you guys say is the best bang for your buck...including labor if we werent to do it ourselves
Nitrous!
Nitrous is by far the cheapest form of a power adder. It does have to be refilled so in the long run it could cost as much if not more than a supercharger or turbo, but that could take a while. Also, there are some drawbacks to nitrous, such as not having it all the time, but you just have to make sure the bottle is filled.
 

BioHazard the Reaper

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ahh dont go nitrous....i believe using nitrous, to make power, becuase you have no power is stupid....if youve a car that is badass alread, nice good high perfomance motor, then hell ya toss nos on, but to put it on to save money is stupid....nos can cause a lot more probs, in the long run than a turbo/super. personally id say a supercharger is cheaper to put on, a centrifugal one at that....all you need is a bracket or two, and a belt, this makes labor cheaper, an di believe you can get superchargers a little cheeper, as you dont need a exhuast mainfold or nothing
 

Handlebars

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ok here goes with my unnecessarily long techno babble about newtons theorys and crap like that, but i know you guys probably dont want to hear it. so heres a (relatively) condensed version

supercharger- as discribed above, there are 2 major kinds of superchargers, the positive displacement and the centrifrugal. the p/d (or jrsc for jackson racing, the most popular p/d) isnt really very effective on small engines. most of the blowers you see on muscle cars are of this sort, but remember that muscle cars already have tons of torque needed to spin the screws, and their sheer size lets them push a lot of air. but hondas dont, and this design doesnt work nearly as well on small displacement, high rpm engines because the design hinders high rpm breathing. jr's own website lists a d16z6 motor as gaining 40whp and 20wlb/ft of torque, which is, well kinda pitiful compared to everything else out there. the torque is boosted on the low end though, so the car feels a lot stronger around town, but it just doesnt have the high rpm breathing that is the honda hallmark. if you get the endyn upgrades, it works a lot better, but they are expensive. this is a good choice if your looking just to add more hp than bolt ons, but dont want anything beyond that.

vortech, or centrifrugal s/c's work the same way as the compressor side of a turbo, but it is driven by a belt connected to the crankshaft instead of exhaust gases. this makes it less physically (or frictionally) efficient, but more thermally efficient. basically, it takes more power from the engine to drive it, but it makes far less heat both underhood and to the intake air, giving lower intake temps, more hp and less chance of detonation. it gives less hp per lb of boost as a turbo, but it puts less stress on the engine. it makes its power in a very linear way, meaning that your hp curve is going to look the same, its just going to be higher up in the scale. contrary to the jrsc, the vortech makes very little low end power, and very good top end. also unlike the jrsc, it can use a traditional intercooler. boost can be upgraded with smaller pulleys, but may people have problems with belts slipping at higher boost levels (the belt is smooth, not toothed). like the jrsc, it works good at stock boost, and even with upgraded boost, but you will not see the gains of a turbo, and dispite the claim of 'no turbo lag', it produces very little boost in low rpm, perfectly simulating turbo lag.

turbo- a turbo is the most popular application for boost. contrary to popular belief, most of a turbo's power does not come from the pressure of the exhaust, it comes from the heat exchange. i could go into the physics of it, but i really dont feel like it. basically, the bigger difference in heat between the exhaust manifold and the downpipe, the faster the turbine spins. as air cools, it releases energy. the faster it cools, the more energy gets released into the turbine. thats why putting a 3" turbo back exhaust on a turbo car has such a dramatic effect on performance. anyway, a turbo is the most energy efficient of the 3 major boost applications. on average, a turbo will "take" 5 hp for ever 100 hp it makes (meaning that for a theoretical 105 hp, you actually see 100 hp at the crank. this is due to the exhaust backpressure created by the turbine) where as the average supercharger "takes" 30 hp for every 100 it puts out (130 theoretical hp, but you see 100 at the crank, the 30 is necessary to drive the s/c belt). a turbo also adds a lot of heat to the engine bay, and even with a large intercooler, it injects pretty hot air into the intake, reducing efficiency and increasing the chance of detonation. all air, as it is pressurized, heats up. s/c's only add the heat from this pressurizing, where as the turbo also adds the heat from the exhaust. exhaust gas temps can exceed 1800 degrees, and both the turbo housing and the turbine wheel get very very hot, heating up the intake charge more, in addition to the heat from pressurizing. a turbo, no matter how small will have a certain "boost threshold" which is the point at which your intake manifold goes from being in a vaccume to being under boost, and some turbo lag, which is the time between when you floor it and when the exhaust gases are heated sufficiently to spin the turbine wheel, the wheel spins the compressor, and the intake charge is compressed enough to satisfy the demand for power. the two terms are different, and i know its hard but they are unique and must be kept separate. a properly sized turbo ( for stock boost levels, something like a t25, 14b or t3) will have a low boost threshold and little lag, but will make much higher gains top end than either s/c will.

the choice of s/c and turbo basically comes down to the user. if ultimate reliability is the highest goal and power production is second, than there is no contest- get a supercharger. which one you get depends on where you want your power- down low or top end. if you want higher power production, more adjustability (s/c's boost is set with pulleys, and is not variable from the car, where as a turbo is adjustable with a boost controller) then go for a turbo. psi for psi, it will make more power than a s/c over a larger rpm range. hope this helps.
 

TurboZinc

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Originally posted by "BioHazard"

ahh dont go nitrous....i believe using nitrous, to make power, becuase you have no power is stupid....if youve a car that is badass alread, nice good high perfomance motor, then hell ya toss nos on, but to put it on to save money is stupid....nos can cause a lot more probs, in the long run than a turbo/super. personally id say a supercharger is cheaper to put on, a centrifugal one at that....all you need is a bracket or two, and a belt, this makes labor cheaper, an di believe you can get superchargers a little cheeper, as you dont need a exhuast mainfold or nothing
Why? Why is using nitrous to make power stupid? Why is it then that using a supercharger to make power when you have none stock not stupid? How is running nitrous any more dangerous than running a superchager (or turbo)?
As long as you don't do anything stupid with either they can both be extremely safe, streetable ways of producing horsepower.
 

BioHazard the Reaper

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well nitrous to me is just a stupid thing to use....i dont use it and will never use it, i feel its to cheap a way to get power....
 

TurboZinc

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Originally posted by "BioHazard"

well nitrous to me is just a stupid thing to use....i dont use it and will never use it, i feel its to cheap a way to get power....
:roll:
 

Team 4R

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i think i'll jump in here with some details.........

first, centrifugal superchargers, namely vortech's, do use blow-off valves as they are essentially belt-driven turbos. most of handlebar's info is right on, except where he mentioned the exhaust temps...... you should never ever be seeing exhaust temps of 1800 degrees...... 1600 is considered engine death, and i'm pretty sure aluminum buckles at that temperature. as always, you want to keep all temps down as low as possible, but less than 1400 is a more than reasonable target.

as far as nitrous oxide goes............... it is a dumb idea, in my opinion. BUT, that does not mean it is a universally dumb idea. i have seen a few big-turbo setups that use laughing gas to very effectively overcome turbo lag. nitrous is also incredibly useful in keeping intake temps down when sprayed across a surface (intercooler) or directly into the throttle body..................

that's it for now.
 

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oh ya....... neither a turbo nor an sc is more reliable than the other. either method will work, or not work, depending on the quality of the installation.

on a small displacement four-banger i would immediately rule out the use of a roots-type blower. if shooting for ~300hp (from a b-series motor) the choice between turbo or vortech is entirely personal preference, as both will get you there with ease.......... for bigger power than that, a turbo makes the task much simpler.

the vortech system costs about $4k done properly. for that price you could get a top-of-the-line turbo system or a nice turbo kit and engine management.

justin, on your d-series, the choice would have to be turbo..... i'm not 100% sure, but i don't even think there are any centrifugal superchargers made for your motor.
 

93B18C5Hatch

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In you have to use NOS, that means your losing.. besides Ive seen pics of a car blown up in some dudes garage because it was to hot out side. if thats not dangours i dont know what it.
 


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