Turbo vs compressor!! (?) Options

[Bakkmagedon]

Hey!

I wanna tune my at200 engine, and wonder if its possible (and chost) to compressorcharge it?

what is best to do, compressor or turbocharge ?

Hope for answers

This post has been edited by Bakkmagedon: Jun 6, 2009 - 1:48 PM

[terbear4god4life]

wtf is compressor charge?

[Bakkmagedon]

I guess in English its the same as supercharger My bad

[Nartanian]

Hey!

I wanna tune my at200 engine, and wonder if its possible (and chost) to compressorcharge it?

what is best to do, compressor or turbocharge ?

Hope for answers

Definitely go turbo

[ZGear]

Depends on your use of power and daily use. All-out drag car / All-out track car / All-out AutoX....etc.

[AnaXyd]

Compressor is better on low rpm, i have heard. But, compressor is connected with belt to your engine, which will use more gasoline than turbo. Both turbo and compressor is the perfect match, or just twinturbo!

VW have the TSI engine, which is both turbo and compressor. Pretty awesome technology which drains a lot of horsepower from a small engine.

[Dragondog]

supercharge will drain alot of hp since it spools from the motor but it does give the hp it drains back plus more.. as turbo does not drain hp it uses ur xhast to spool but giving it a longer time till it bost ur car..............................

supercharge is an instint boost.....but takes hp to get hp....from what i here both can put out same hp depending on the types...in other words nither one will give more hp then the other overall

400hp motor supercarged giving the motor 350hp but instintly adding 150hp overall 500hp...down side if u decide to use boost control for it if u turn it down it will still drain ur 400hp tp 350hp and still drain ur gas

400hp motor turboed adding 100hp overall 500hp...(but only adding 100hp for when it spools) giving ur motor the 400-500hp fluctuation.. adding boost control to drop boost and only giving ur car 400hp

turbo has a delay for you wont get instint boost.......and does not drain hp

it all depends on if you want to sacrifice gas and hp to get instint boost or if u want to have a sudden boost in the middle of each shift.........most will frown on the suppercharger for it draining of gas and power so they then just twin turbo ther cars or just go single and use nos for the inbetween bursts of boost

This post has been edited by Dragondog: Jun 6, 2009 - 7:19 PM

[Cuts_the_Pilot]

There is so many variables into what you choose.

a stock size turbo on a 3s gives plenty good enough responce with delivering reasonable power (if your only keen on a mild power up)

Now with superchargers there is two types.

1. Positive displacement. These are blowers like the Eaton m90, Toyota SC12 and SC14 etc. These deliver a set volume of air to the engine per revolutuion. These draw the most power from your engine but gives you the instant responce mentioned earlier.

2. Centrifugual. Like Rotrex or Powerdyne do not deliver a set ammount of volume per revolution. These use a tip speed compressor like a turbo (looks like a turbo from the front). These DONT give instant boost, you kind of have to wait for it to "spool" up like a turbo. I put a rotrex on my mates zzt231 (7th gen celica) and with the smallest pulley it made 180 kw atw, around 300 hp at the flywheel, this was at 12 psi @ 8000rpm.


In my opinion go the turbo.

[manphibian]

in my opinion, get a GT-Four!

I don't know if they are available in Norway or not, but it will be cheaper to import one than s/c or turbo yours......?

[Mstoochn]

Compressor is better on low rpm, i have heard. But, compressor is connected with belt to your engine, which will use more gasoline than turbo. Both turbo and compressor is the perfect match, or just twinturbo!

VW have the TSI engine, which is both turbo and compressor. Pretty awesome technology which drains a lot of horsepower from a small engine.

sorry to burst your bubble, the new TSI is a turbo charged super water cooled engine not a turbo and supercharged engine. the TSI is the turbo model and the FSI is the supercharged model

[Bakkmagedon]

Thanks for answers! : )
After what you are telling me, I think turbocharge will fit me better. This is my daily use car(in the summer) and make it use more fuel I didn`t like
And friends are telling me that supercharge will chost more than turbocharge too. I don`t know if the engine will manage bouth supercharge and turbo, but I probably cdont have the money to do it x)

And about the gt4 in Norway. . When we are speaking about cars with powers in norway i just wanna cry. Its so expensive to import if you wanna register them, it MUSt be left-hand drive +++ Those GT4 in good shape thats for sale that is registered will chost min 30 000 dollars (200 000 norwegian kroner)

I think i will go for the turbocharge, would be nice to have instant power, but its pretty cool to feel it "kick" away to:D

Anyone know how much hp people usally get when they turbocharge the 1.8l at200 engine ?

[AnaXyd]

Compressor is better on low rpm, i have heard. But, compressor is connected with belt to your engine, which will use more gasoline than turbo. Both turbo and compressor is the perfect match, or just twinturbo!

VW have the TSI engine, which is both turbo and compressor. Pretty awesome technology which drains a lot of horsepower from a small engine.

sorry to burst your bubble, the new TSI is a turbo charged super water cooled engine not a turbo and supercharged engine. the TSI is the turbo model and the FSI is the supercharged model

The label in front of a Scirocco TSI told me so..


Please read: http://www.vwvortex.com/cgi-bin/artman/exe...=7&num=1496

The compact 1.4 litre direct-injection engine develops up to 125 kW / 170 PS and has a maximum torque of 240 newton metres in the range from 1750 to 4500 rpm thanks to the combination of an exhaust turbocharger with a mechanically driven compressor.

This post has been edited by AnaXyd: Jun 7, 2009 - 10:39 AM

[ksporry]

I don't see anyone making any remarks regarding the difficulty of upgrading/fitting their engine with a turbo or super charger.
Surely there will bea difference? E.g. with a turbo you need blow off and/or bypass valves for during shifting to prevent pressure spikes. From what I understood you won't have have this problem with a super charger as it delivers the amount of pressure you need depending on the RPM of the engine (assuming you don't keep your foot on the accelerator during shifting that is). This means you only need a boost pressure regulator and set it up once.
It means you can leave your exhaust system intact (though you probably still need to get an intercooler and ensure suffiecient fuel flow).
With a turbo you will need a new exhaust system, new intake system, boost control, bypass/dump valves, fuel controllers, engine controllers, and a whole lot of time and patience to set it all up.

[Cuts_the_Pilot]

Ksport your over simpflying things.

you dont think you need to upgrade your fuel system and ecu with a blower too.

they in effect do the same job, push more air into the engine, more air requires more fuel regardless of what pushes it.

You dont have to run a bov (what you misname a bypass valve) running low boost a bov (blow off valve) isnt needed at all.

Superchargers are still a lot of work. Mounting it in direct line with the belt (if its off to the side even a small ammount it will rob you of power and wear the belt out and pul uneven wear on the bearings in the blower. You still need to make up pipework to get air to and from the blower, and in most cases you still run an intercooler with a supercharger.

The upside with fitting a supercharger is as you mentioned you dont need to change your exhaust. But then think your engine is going to be making an extra 50% or so, your tiny stock exhaust wont flow enoug and will require upgrading anyway.



With a turbo you need to get an oil feed and drain and usually a coolant feed to it, so you could take the oil feed from the oil pressure sender in the head (not the best way but it would do the job) as for the drain you need to take you sump off and get a peice of thread or bung welded into it.

You need an exhaust manifold, lucky you can buy a turbo manifold for pretty much anything off egay these days so you'll be right there. Then a dump pipe needs to be made, it could either mate to your existing exhaust (might be too restrictive as i mentioned earlier) or get a whole new one made while your at it. Any exhaust place should be able to knock up a full exhaust in 3" m/s mandrel bent for around $400 us. Or make it yourself if your handy with a welder and hacksaw/grinder/drop saw.

Still need an intercooler to be mounted and piping to be made up, but you need that with a supercharger anyway so no real difference there.



Either way you are going to need at least an upgraded fuel pump and probably injectors too, and an ecu to control it, and intercooler mounted and pipework to be made, and exhaust modified either way etc etc, its still a big job.

[Dragondog]

I don't see anyone making any remarks regarding the difficulty of upgrading/fitting their engine with a turbo or super charger.
Surely there will bea difference? E.g. with a turbo you need blow off and/or bypass valves for during shifting to prevent pressure spikes. From what I understood you won't have have this problem with a super charger as it delivers the amount of pressure you need depending on the RPM of the engine (assuming you don't keep your foot on the accelerator during shifting that is). This means you only need a boost pressure regulator and set it up once.
It means you can leave your exhaust system intact (though you probably still need to get an intercooler and ensure suffiecient fuel flow).
With a turbo you will need a new exhaust system, new intake system, boost control, bypass/dump valves, fuel controllers, engine controllers, and a whole lot of time and patience to set it all up.

lol slow down man ur getting over worked on this.......its not as you say...a turbo is not as hard and difficult as you make it out to be......you dont need a new intake system....you dont need boost control..altho its good to have and EASY to get....you dont need fuel controllers......getting a blow off valve is a simple deal.....engin controllers? you mean ecu?.....and depending on how much you plan to boost you dont need to upgrade injectors and fuel rail and fuel pump........you can easly get a bolt on and your good to go, give or take....iv never seen a supercharger installed that was eareir then a turbo

This post has been edited by Dragondog: Jun 10, 2009 - 5:08 PM

[ksporry]

Not really over worked (sorry if I gave that impression), but I do have a 3S-GE N/A engine, and that one will definitely need new fuel injectors if I don't want to wreck the engine, even if I run it at low boost (6 psi-ish, which I need to since its a 3SGE N/A engine). If I have new fuel injectors, I need a fuel pressure regulator (maybe also a new fuel pump) and fuel controller to allow more fuel to be send to the engine.
Can't do blow off valves as it is not street legal in the UK (and I do want to drive it legally on the road).

But all in all I guess its true that most mods apply to both super charger and turbo's alike...

[Dragondog]

Not really over worked (sorry if I gave that impression), but I do have a 3S-GE N/A engine, and that one will definitely need new fuel injectors if I don't want to wreck the engine, even if I run it at low boost (6 psi-ish, which I need to since its a 3SGE N/A engine). If I have new fuel injectors, I need a fuel pressure regulator (maybe also a new fuel pump) and fuel controller to allow more fuel to be send to the engine.
Can't do blow off valves as it is not street legal in the UK (and I do want to drive it legally on the road).

But all in all I guess its true that most mods apply to both super charger and turbo's alike...

being legal is understandable..........and what do you mean fuel controller?.......is that the uk term for a piggyback......thats crazy a bov being illegal you guys strick out there, jk....i dont think ull need a new fuel pump...unless urs is going out?.....and unless your trying to get like 500-600hp...but for just a little bit more hp then stock......you may be able to get away with just useing a piggyback, low boost turbo, and not have to get new injectors....specilly if all ur doing is gonna run 6psi-ish...thats like turboing a beams....but dont take my word for it for the way you wanna do ur car sounds safe and reliable..what cc injectors?.........if you wana go high hp ur lookin at fuel pump(s), fuel rail, injectors, piggyback perferably a stand alone and a great innercooler for your turbo, as well as some other stuff you mentioned

This post has been edited by Dragondog: Jun 12, 2009 - 4:07 AM

[Cuts_the_Pilot]

i dont think ull need a new fuel pump...unless urs is going out?.....and unless your trying to get like 500-600hp...but for just a little bit more hp then stock......you may be able to get away with just useing a piggyback, low boost turbo, and not have to get new injectors....

Better to be safe then sorry (ie leaning out the engine on the road and blowing a hole in a piston)

Injectors, pumps and regs arnt super expensive things to buy/upgrade. You will deffinatly need some sort of ecu, best going full stand alone rather then piggy back if you can afford it.


to give to all an idea of inj sizes etc. With the blower i put on my mates zzt231 celica we started with just MWR 500cc Injectors (stocks are 310) and a MWR Fuel Pump 255lph, when it was being tuned we couldnt hit lift because there wasnt enough fuel supply.

So we went and bought a MWR Fuel return line kit and an AEM Fuel pressure regulator, now with more fuel pressure (and a rising rate one at that) there is only just enough (including a safty margin)fuel flow for the lift zone (ie 6000 - 8000 rpm).

I know the 2zz is a high revving engine but im just using it as an example of how you should do you injectors and pump, because like ive said even not in lift 190cc bigger injectors and pump wasnt enough fuel supply. Ohh btw it made 180 kw at the wheels (around 280 engine hp)

This post has been edited by Cuts_the_Pilot: Jun 13, 2009 - 12:32 AM

[DEATH]

There is soooo much misinformation scattered in with true facts that this thread ought to be cleaned up before it gets anyone else confused [and perhaps causes someone to destroy a motor].
Basically everything Cuts said is true and his advice should be followed - the rest forget about it. This site is thick with threads about how one or the other of us Turbocharged our NA motors - it's easy to do if you do alot of homework and buy the right parts. There is no need to only run 6psi on an NA motor - it's all in the tuning.
Dragondog IDK where you get your info from but telling someone they don't have to upgrade their fuel system when they add a turbo or supercharger is a very bad idea. The whole point of either device is to shove more air into the engine so that more fuel can be burned with each cycle of the engine to produce more power. So why would you think it was possible or even desireable to add a charger of some type but leave the fuel system stock? Also there is no difference in fuel consumption between a supercharger and a Turbo charger when they are producing boost - one style will not necessarily require more fuel than the other.
Please guys - if you truly don't know the answers to these questions please leave the speculation out of these threads.

This post has been edited by DEATH: Jun 12, 2009 - 10:19 PM

[Dragondog]

i know that death i didnt say they shouldnt....not even for a supercharger....i was saying if you r only gona run that LOW of a boost y bother........how ever i did say if your gona go HIGHER then CHANGE the fuel system and do it right I EXPLAINED THAT (plz reread my posts)........i helped a friend with his honda low boost.......5yrs....and it still runs strong, only using a piggyback......if hondas r that much better then sign me up with the honda guys........also death i read and i read and i cant find anything that backs up your answer on a s/c will not use up more gas then a turbo for all i find is it will use up more gas for it creates a extra drag on the motor......also s/c r a bit easier to install then turbos (IT DEPENDS) but imo its not worth it on a 4banger again thats imo...they r easier ON SOME CARS AND TRUCKS cuz it is just a bolt on and it conects to the crank belt and does not require cooling but the guys recomend cooling for relibility.....what would make it hard is finding room for it cuz it has to be mounted to the front of engin for the EXTRA pully to conect the crank....id like to know were you get ur info...........my replies r clear to me if ther hard for you to understand im sorry, and i do alot of reading and surfing i dont just grab info from one source and stick wit it, it comes from many...................................i also said perferably a standalone....but i dont go around asuming every one has multi thousands to throw around so i explaind it in a cheap way....cheap fast reliable pick two......i went with cheap and reliable....if you want fast then i would of picked fast and reliable and that is were cuts took over....im not sayin hes wrong at ALL...cuz hes is right...i go by the moddo cheap fast reliable pick two...so i picked.....sorry if im too confusing...and death i would never challeng your knowledge on cars iv seen what you did to yours its bad a$$....its if i am wrong then so is the mojority out ther i read from...and the guys i talk to...edit: heres somtin i found mite be of help......read this and dont missread it.......from
http://ateupwithmotor.com/terms-and-defini...ercharging.html

Q: What's a supercharger?
A: An internal combustion engine works by drawing a mixture of air and fuel (the intake charge) into its cylinders, compressing it, and burning it. The more air/fuel mixture that can be crammed into the cylinders to burn, the more power the engine produces. You can increase power in three basic ways: you can improve the engine's ability to draw more air and fuel into the cylinders and expel its burned exhaust gases (its volumetric efficiency, or 'breathing'); you can increase the swept volume of the cylinders (the engine's displacement), so you can fit more air and fuel into each cylinder; or you can force the intake charge into the cylinders under high pressure, squeezing more air and fuel into the available volume. Forcing air into the engine at higher than atmospheric pressure is called supercharging. A supercharger is a mechanical air compressor that pressurizes the air going into the engine. There are several types of compressor used for car and truck engines, most commonly Roots-type, centrifugal, and Lysholm compressors; each has pros and cons, but they have the same basic function.

Q: So, what's a turbocharger, then?
A: As we just said, a supercharger is an air compressor, and it requires a source of power to operate the compressor mechanism. Most automotive superchargers are run by a drive belt (or occasionally a train of gears) operated by the engine, much like a power steering pump or air conditioning compressor. An alternative is to run the supercharger with a turbine wheel placed in the engine's exhaust manifold, turned by the flow of burned exhaust gases rushing of the engine. An exhaust-driven supercharger is called a turbocharger. (Years ago, they were often called turbo-superchargers, but that term has fallen out of common use, although it is occasionally applied to combinations of engine-driven and exhaust-driven superchargers.)

Q: What's the advantage of supercharging (or turbocharging)?
A: More power! The more you increase the pressure of the intake air above the local atmospheric pressure (boost), the more power the engine produces. Automotive superchargers for street use typically produce a maximum boost pressure between 5 and 15 pounds (0.33 to 1.0 bar), providing a proportionate increase in power. This is particularly useful at high altitudes: thinner air has less oxygen, reducing power by around 3% per 1,000 feet above sea level, but a supercharger can compensate for that loss, pressurizing the intake charge to something close to sea level pressure. (Superchargers are popular for high-altitude aircraft piston engines for precisely that reason.)

Q: Does adding a supercharger or turbocharger burn a lot of fuel?
A: All else being equal, yes. Engines burn air and fuel at an ideal (stoichiometric) ratio of about 14.7:1, which means that if you burn more air, you must also burn more fuel. Even when the supercharger isn't producing much -- or any -- boost, a supercharged engine is somewhat less fuel efficient than a non-turbocharged (normally aspirated) engine of the same displacement and configuration. On the other hand, a supercharged engine tends to consume less fuel in day-to-day driving than a larger displacement, normally aspirated engine of similar power. For example, a 2.0L turbocharged four-cylinder engine with 240 hp will be somewhat less thirsty than a 240-hp 3.5L normally aspirated V6 engine, at least in normal driving. As any owner of a Subaru WRX will tell you, though, if you use the boost a lot, you'll pay the price at the pump.

Q: Why use a supercharger instead of just using a bigger engine? Wouldn't that be easier?
A: To some extent, it would be. A supercharger significantly increases an engine's specific output -- the amount of power it generates per unit of engine displacement (usually quoted in terms of horsepower per cubic inch or horsepower per liter), but, as the old adage says, there's no substitute for cubic inches (or, more pithily, no replacement for displacement). Increased displacement provides more power without the added cost, complexity, and sometimes nonlinear behavior of superchargers. Still, a large-displacement engine usually ends up being bigger and heavier than one of small displacement, which makes it harder to fit under the hood, and does unfavorable things to weight distribution. A smaller, supercharged engine can provide similar power with less bulk and somewhat lower average fuel consumption and carbon dioxide emissions. In addition, some countries, like France and Italy, levy prohibitive tax and licensing surcharges on cars with large-displacement engines, making a smaller displacement, supercharged engine much cheaper to buy and operate.

Furthermore, any existing engine design can only have its displacement increased so much without a major redesign, so the addition of a supercharger or turbocharger can be a useful way to pep up an existing engine that has reached the limits of its growth potential. It's a relatively easy "bolt-on" power increase that doesn't require a vast amount of engineering work.

Q: Why don't superchargers produce maximum boost all the time? What's "turbo lag?"
A: The amount of boost any supercharger produces is dependent on the size and rotational speed of its impeller(s), as well as the type of compressor it uses. (For example, centrifugal superchargers, whose output increases proportionally to the square of the rotation speed, are most efficient at high speeds, while Roots superchargers are most efficient at lower speeds.) The peak operating speed of a typical automotive supercharger is more than 30,000 rpm, more than 100,000 rpm for some turbochargers. The compressor does not produce its full boost until the impeller has reached that speed.

Let's look at a specific real-world example: the belt-driven Paxton Model SN supercharger offered as an option on mid-sixties Shelby GT-350s. The Model SN was a centrifugal supercharger with an impeller was 5.78 inches in diameter, and it was geared to rotate at just under six times the speed of the engine crankshaft. It produced a maximum boost of 5.0 psi at an impeller speed of just under 30,000 rpm, which translated to an engine speed of 5,000 rpm. As we mentioned, in a centrifugal supercharger the boost is proportional to the square of the rotation speed. At an engine speed of 2,500 rpm, therefore, boost drops by a factor of four, to about 1.25 psi. Cut it in half again, to 1,250 rpm, and the boost is only about 0.31 psi.

What did that mean in practical terms? When the supercharger was making full boost it provided a significant amount of extra power -- close to 30%. (Shelby claimed the supercharged GT-350 made 390 gross horsepower, compared to 306 for the normally aspirated version.) At very low speeds, though, its boost was negligible, not enough to make up for the power used to run the compressor. This was borne out by contemporary acceleration tests: the supercharged engine was no faster than its normally aspirated counterpart under about 40 mph, but it was noticeably faster to 60, and had significantly higher quarter-mile trap speeds.

Turbochargers, which usually use centrifugal compressors, have the same limitations, which are further complicated both by their higher peak speeds and the fact that the speed of the impeller is dependent on the speed of the exhaust stream, not the engine speed. Unlike an engine-driven supercharger, the turbine speed isn't fixed; it varies with throttle position (among other things). At steady cruising speeds, the turbine is often spinning well below its boost threshold, that is, turning too slowly to provide any boost. When you press the gas pedal the speed of the exhaust gases increases and the turbine begins to accelerate, but there's a delay while the turbine overcomes its own inertia and accelerates (spools up) to peak speed. Since that peak speed is usually quite high, this produces a brief but annoying delay, known as turbo lag or boost lag, where not only does the turbocharger not produce any extra power, it actually reduces output slightly because of the increased back pressure the turbine creates in the exhaust stream.

The severity of turbo lag often depends on how much boost the turbocharger produces. More boost requires either a bigger compressor -- which has more inertia -- or a higher operating speed, either of which take longer to spool up. Engineers have developed various tricks to reduce turbo lag, including reducing the mass of the turbine blades, changing their shape to improve their acceleration, and even adding movable nozzles that change the direction at which the exhaust stream hits the turbine blades, depending on their speed. (Porsche recently introduced a "variable geometry" turbo system, claiming it to be a first, but Chrysler had something very similar on its short-lived VNT turbo engine back around 1990.) Some sports cars have also used two or more sequential turbochargers of different sizes, a smaller turbo offering good low-speed response and a bigger one that takes over to provide maximum boost at higher speeds. The limited-production Porsche 959 used sequential twin turbos, as did the now-defunct Mazda RX-7, Nissan 300ZX Twin Turbo, and Toyota Supra Turbo.

Reducing turbo lag is easier with turbochargers whose maximum boost is relatively low; the "light-pressure turbochargers" used by some Saab and Volvo engines, for instance, don't produce a great deal of boost, but they have little lag and a fairly linear power curve.

A more complex alternative is a two-stage turbo-supercharger, which uses both an engine-driven supercharger and a turbocharger in sequence. The supercharger is designed to produce its maximum boost at low speeds; at higher speeds, a clutch disengages the supercharger and the turbocharger provides the boost. This was not uncommon on aircraft engines in the 1940s, and Volkswagen recently reintroduced the concept with its "twincharger" engines, now used on some European Polo and Golf models.

Q: Are there other disadvantages of superchargers and turbochargers?
A: Definitely. The most obvious are cost and complexity. Aside from adding a bunch of extra parts to the engine (which means more to break), the moving parts have to be precisely machined and quite strong. Turbochargers require fairly exotic materials to withstand both the high temperatures of the exhaust system and their very high operating speeds. Forced-induction engines need to be well lubricated, as well, and they tend to put a big strain on the engine's oil system, requiring good-quality oil and frequent oil changes to avoid a build-up of sludge.

Another potential problem is detonation. If you increase the pressure of the intake air, you also increase its temperature. When the mixture enters the cylinders it is compressed before it burns, raising its temperature even further. If the mixture is too hot, it may be prematurely ignited by hot spots within the combustion chamber (this is called detonation, preignition, or knock). Detonation can cause severe internal engine damage. To reduce the risk of detonation, forced-induction engines often have their compression ratios reduced, so the pistons do not compress the mixture as much prior to burning. This avoids detonation, but it means that the engine's power output is reduced, particularly when the supercharger is not producing much boost. Many forced-induction gasoline engines require higher octane fuel, which is less susceptible to knock, but costs significantly more.

As we've mentioned above, superchargers consume a certain amount of engine power even when they aren't producing useful boost, and turbochargers increase back pressure in the exhaust, which also costs power. The compressor can also create a certain amount of internal drag at low speeds. At maximum boost, the increased power provided by the compressor far outweighs these parasitic losses, but they make the engine less efficient off-boost.

Superchargers and turbochargers also take up a little more space in the engine compartment and add a certain amount of weight. These penalties are modest compared to the benefits (bolt-on superchargers typically weigh less than 50 pounds and fit fairly easily under the hood), but they're not negligible.

Moral of the story: there is no free lunch.

Q: What's an intercooler?
A: As we said, increasing the pressure of the intake air raises its temperature, which is really not desirable. Not only does it increase the risk of detonation, it lowers the density of the intake charge, which starts to defeat the whole purpose of supercharging. There are several tricks that can reduce that temperature. One is to inject a little bit of liquid (such as water and alcohol) into the intake manifold; some of the thermal energy of the compressed air goes to vaporizing the liquid, reducing the air's temperature. Another method is to add an intercooler, which is a heat exchanger -- basically, a small radiator -- that removes some of the heat from the pressurized air before it enters the engine's intake manifold. A properly designed intercooler dramatically reduces the intake air temperature, avoiding detonation and, as a bonus, increasing its density. Intercoolers aren't really necessary for low levels of boost (less than about 5-6 psi), but they're virtually mandatory at very high boost pressures.

Of course, adding an intercooler further increases cost, complexity, mass, and bulk. The heat the intercooler extracts also needs somewhere to go. If it's an air-to-air intercooler, it needs a good flow of cooling air; if it's an air-to-water intercooler, the engine needs a bigger radiator to cope with the extra heat added to the engine's cooling system.

Q: How long have superchargers and turbochargers been around? Did Saab invent the turbocharger?
A: The Roots-type compressor has been around a lot longer than the automobile -- it was patented back in the 1860s for use in ventilating mine shafts, and the first patent for an automotive version was filed by Gottlieb Daimler (of Daimler-Benz fame) in 1900. Rudolf Diesel patented the supercharged diesel engine in 1896, and the centrifugal supercharger was patented by Louis Renault in 1902. The turbocharger was invented by Alfred Buchi and patented in 1905. Turbochargers were used on diesel engines starting in the 1920s, but the difficulty of manufacturing turbines able to reliably endure the higher exhaust temperatures of gasoline engines kept them from wide use on petrol engines until the mid-1930s. Turbochargers became common on aircraft engines shortly before and during World War Two.

Every so often you'll find someone on the web claiming that Saab offered the first production turbocharged gasoline engine, which is simply not true. Turbocharged race cars began to appear in the early 1950s. The world's first production car with a turbocharged engine was the 1962 Oldsmobile Jetfire, followed a few weeks later by the 1962 Chevrolet Corvair Monza Spyder. The Olds turbo lasted only two years, the Corvair turbo for four, but they beat Saab by more than a decade.

Turbochargers are nearly universal on modern diesel engines, but forced induction for petrol engines has fallen in and out of favor over the years. Turbochargers became popular in the late 1970s, then nearly faded away in the early 1990s in favor of bigger, normally aspirated engines. With increased political pressure for better fuel economy and reduced carbon dioxide emissions, they're again becoming common, and some engineers think that light-pressure turbochargers will eventually become standard, just like fuel injection. The motivation, as before, is to try to extract big-engine power from smaller, less thirsty engines.

also read
from=====http://www.moddedmustangs.com/forums/v6-mustangs/107265-everything-turbo-supercharger.html

Turbochargers and Superchargers

Let's start with the similarities. Both turbochargers and superchargers are called forced induction systems. They compress the air flowing into the engine. The advantage of compressing the air is that it lets the engine stuff more air into a cylinder. More air means that more fuel can be stuffed in, too, so you get more power from each explosion in each cylinder. A turbo/supercharged engine produces more power overall than the same engine without the charging.

The typical boost provided by either a turbocharger or a supercharger is 6 to 8 pounds per square inch (psi). Since normal atmospheric pressure is 14.7 psi at sea level, you can see that you are getting about 50-percent more air into the engine. Therefore, you would expect to get 50-percent more power. It's not perfectly efficient, though, so you might get a 30-percent to 40-percent improvement instead.

The key difference between a turbocharger and a supercharger is its power supply. Something has to supply the power to run the air compressor. In a supercharger, there is a belt that connects directly to the engine. It gets its power the same way that the water pump or alternator does. A turbocharger, on the other hand, gets its power from the exhaust stream. The exhaust runs through a turbine, which in turn spins the compressor.

There are tradeoffs in both systems. In theory, a turbocharger is more efficient because it is using the "wasted" energy in the exhaust stream for its power source. On the other hand, a turbocharger causes some amount of back pressure in the exhaust system and tends to provide less boost until the engine is running at higher RPMs. Superchargers are easier to install but tend to be more expensive.


The Similarities between Superchargers and Turbochargers

Turbochargers and superchargers are similar in that they both compress air to higher than atmospheric pressures. Normal or standard atmospheric pressure is about 14.7 psi (pounds per square inch or "psi"). The job of the compressor common to both turbochargers and superchargers is to increase air pressure so that more air is forced into the cylinders ("forced induction"). This increased air volume ("boost") is mixed with a proportionately increased fuel volume which, when burned in the combustion cycle, results in increased horsepower and torque production.

Power Curve Differences

Because they are belt driven from the engine crankshaft, centrifugal and roots superchargers build boost as rpm increases in a linear fashion. As engine rpm increases, the supercharger compressor speed (and boost level) increases to the point of peak boost occurring at peak engine rpm. For example, a centrifugal or roots supercharger designed to produce 8 psi at 6,000 rpm may produce as little as 2.5 lbs. of boost at 3,000 rpm. Screw-type superchargers are more like turbochargers in that they build boost much earlier than a centrifugal or roots-type, and they are also belt-driven. Turbochargersare exhaust driven, and come up to speed very quickly (almost instantly if properly sized), and will reach the same 8 lb. peak boost level as low as 2,500 rpm. There will always be lag with a turbo system. Small size turbos are good for spooling at lower rpms but the user must utilize a wastegate to slow down the fans when boost gets too high. thus at a higher rpm. smaller turbos loose their appeal. On the other hand, you can use a twin turbo setup with a small and a large turbo mounted and this does well for having boost at all rpms.


Efficiency Comparison

Just like the air conditioner compressor on a car, all superchargers, including centrifugal, roots and screw-type, require horsepower to turn them. This "parasitic" drag is always present, even when the car is being driven normally, and can rob 20%-30% of the power being produced by the engine. The result is a significant decrease in fuel economy and less net power produced. Turbochargers, however, are exhaust gas driven and don't require the same parasitic loss to spin the compressor. When driven normally, a turbocharged car will not consume more fuel and, in fact, gas mileage can actually increase. Even when under full throttle, a turbocharger system will produce as much horsepower at 9 psi as a supercharger at 12 psi. Over all though, Superchargers are more reliable than turbos by themselves. This is because of the residual oil that sits inside the bearings can cook due to the high temperatures these turbos operate at; combined with the insane amount of rpms they spin at.


Reliability Comparison

Both superchargers and turbochargers require high compressor rpm to compress the air. This ranges from 30,000-65,000 rpm in superchargers and can be even higher with turbos (over 100,000 rpm). In order to achieve the high rpm levels required to compress the air to the psi required, superchargers must have a step-up mechanism (gears, belts, pulleys or a combination thereof) consisting of numerous moving parts, to convert 6,000 engine rpm to the 40,000+ rpm necessary to build boost. Turbochargers need no step-up mechanism and have only one moving part, the compressor/turbine wheel assembly (see Figure 2). The simplicity of the turbocharger is therefore less prone to mechanical problems. Superchargers must have a belt to drive them, and belt slippage or breakage can be a problem. More serious problems include crankshaft, bearing and engine damage caused by belt tension forces on the crankshaft. Turbochargers have no belt and no direct mechanical connection to the crankshaft, thereby eliminating these problems. It is interesting to note that many automobiles and nearly all large over-the-road trucks use turbochargers that regularly log in excess of a million miles of reliable performance.


Maintenance Comparison

Some superchargers have a separate lubricating system that must be maintained and some don’t. Turbochargers are lubricated by the engine oil, but will require tapping the oil pan to install, and require no additional maintenance beyond what is normally required for a naturally aspirated car.


Streetability Comparison

Superchargers are directly connected to the belt drive system, they are always producing some level of boost and cannot be "turned off". Because turbochargers only produce boost when under load (as in full throttle acceleration), performance under normal driving conditions is no different than if the engine were naturally aspirated. Turbocharged cars exhibit excellent drivability characteristics.


Upgradability and Adjustability Comparison

Superchargers are generally not upgradeable. When higher performance is required beyond the capabilities of a specific supercharger system, the entire system must be replaced. Turbocharger systems, however, are usually upgradeable by simply upgrading or installing a larger turbocharger without requiring replacement of the entire system. Further, adjusting the boost levels on a supercharger requires removing and replacing pulleys, idlers and belts. Adjusting the boost levels on a turbocharger may be accomplished as easy as a simple turn of a boost controller knob from the comfort of the inside of the car or without a controller a different spring must be installed in the wastegate.


Value/Price Comparison

At first glance, turbo systems may appear to cost more. However, if you consider everything that is included in a complete turbo kit that must be purchased in addition to the supercharger kit in order for the supercharger kit to be comparable (not even considering the performance differences), you may find the turbo system is less expensive and a much better horsepower per dollar value. Depends on your unique setup and what the purpose of your car is to decide on which is a better value.


Installation

Because of the few things required, most diy'ers can install a supercharger easily. Turbos require more installation work and also more upgrades to the engines bay. Supercharges on the other hand if not tuned properly can detonate and destroy the top end a lot easier.





Turbo Tech 101 ( Basic )
How a Turbo System Works

Engine power is proportional to the amount of air and fuel that can get into the cylinders. All things being equal, larger engines flow more air and as such will produce more power. If we want our small engine to perform like a big engine, or simply make our bigger engine produce more power, our ultimate objective is to draw more air into the cylinder. By installing a Garrett turbocharger, the power and performance of an engine can be dramatically increased.

So how does a turbocharger get more air into the engine? Let us first look at the schematic below:


1 Compressor Inlet
2 Compressor Discharge
3 Charge air cooler (CAC)
4 Intake Valve
5 Exhaust Valve
6 Turbine Inlet
7 Turbine Discharge

The components that make up a typical turbocharger system are:

The air filter (not shown) through which ambient air passes before entering the compressor (1)
The air is then compressed which raises the air’s density (mass / unit volume) (2)
Many turbocharged engines have a charge air cooler (aka intercooler) (3) that cools the compressed air to further increase its density and to increase resistance to detonation
After passing through the intake manifold (4), the air enters the engine’s cylinders, which contain a fixed volume. Since the air is at elevated density, each cylinder can draw in an increased mass flow rate of air. Higher air mass flow rate allows a higher fuel flow rate (with similar air/fuel ratio). Combusting more fuel results in more power being produced for a given size or displacement
After the fuel is burned in the cylinder it is exhausted during the cylinder’s exhaust stroke in to the exhaust manifold (5)
The high temperature gas then continues on to the turbine (6). The turbine creates backpressure on the engine which means engine exhaust pressure is higher than atmospheric pressure
A pressure and temperature drop occurs (expansion) across the turbine (7), which harnesses the exhaust gas’ energy to provide the power necessary to drive the compressor

What are the components of a turbocharger?



The layout of the turbocharger in a given application is critical to a properly performing system. Intake and exhaust plumbing is often driven primarily by packaging constraints. We will explore exhaust manifolds in more detail in subsequent tutorials; however, it is important to understand the need for a compressor bypass valve (commonly referred to as a Blow-Off valve) on the intake tract and a Wastegates for the exhaust flow.

Other Components

Blow-Off (Bypass) Valves
The Blow-Off valve (BOV) is a pressure relief device on the intake tract to prevent the turbo’s compressor from going into surge. The BOV should be installed between the compressor discharge and the throttle body, preferably downstream of the charge air cooler (if equipped). When the throttle is closed rapidly, the airflow is quickly reduced, causing flow instability and pressure fluctuations. These rapidly cycling pressure fluctuations are the audible evidence of surge. Surge can eventually lead to thrust bearing failure due to the high loads associated with it.
Blow-Off valves use a combination of manifold pressure signal and spring force to detect when the throttle is closed. When the throttle is closed rapidly, the BOV vents boost in the intake tract to atmosphere to relieve the pressure; helping to eliminate the phenomenon of surge.



Wastegates
On the exhaust side, a Wastegates provides us a means to control the boost pressure of the engine. Some commercial diesel applications do not use a Wastegates at all. This type of system is called a free-floating turbocharger.

However, the vast majority of gasoline performance applications require a Wastegates. There are two (2) configurations of Wastegates, internal or external. Both internal and external Wastegates provide a means to bypass exhaust flow from the turbine wheel. Bypassing this energy (e.g. exhaust flow) reduces the power driving the turbine wheel to match the power required for a given boost level. Similar to the BOV, the Wastegates uses boost pressure and spring force to regulate the flow bypassing the turbine.

Internal Wastegates are built into the turbine housing and consist of a “flapper” valve, crank arm, rod end, and pneumatic actuator. It is important to connect this actuator only to boost pressure; i.e. it is not designed to handle vacuum and as such should not be referenced to an intake manifold.



External Wastegates are added to the exhaust plumbing on the exhaust manifold or header. The advantage of external Wastegates is that the bypassed flow can be reintroduced into the exhaust stream further downstream of the turbine. This tends to
improve the turbine’s performance. On racing applications, this Wastegated exhaust flow can be vented directly to atmosphere.



Oil & Water Plumbing

The intake and exhaust plumbing often receives the focus leaving the oil and water plumbing neglected.

Garrett ball bearing turbochargers require less oil than journal bearing turbos. Therefore an oil inlet restrictor is recommended if you have oil pressure over about 60 psig. The oil outlet should be plumbed to the oil pan above the oil level (for wet sump systems). Since the oil drain is gravity fed, it is important that the oil outlet points downward, and that the drain tube does not become horizontal or go “uphill” at any point.

Following a hot shutdown of a turbocharger, heat soak begins. This means that the heat in the head, exhaust manifold, and turbine housing finds it way to the turbo’s center housing, raising its temperature. These extreme temperatures in the center housing can result in oil coking.

To minimize the effects of heat soak-back, water-cooled center housings were introduced. These use coolant from the engine to act as a heat sink after engine shutdown, preventing the oil from coking. The water lines utilize a thermal siphon effect to reduce the peak heat soak-back temperature after key-off. The layout of the pipes should minimize peaks and troughs with the (cool) water inlet on the low side. To help this along, it is advantageous to tilt the turbocharger about 25° about the axis of shaft rotation.

Many Garrett turbos are water-cooled for enhanced durability.

Which Turbocharger is Right for Me or more affectionately known as My Turbo & Me
Selecting the proper turbocharger for your specific application requires many inputs. With decades of collective turbocharging experience, the Garrett Performance Distributors can assist in selecting the right turbocharger for your application.

The primary input in determining which turbocharger is appropriate is to have a target horsepower in mind. This should be as realistic as possible for the application. Remember that engine power is generally proportional to air and fuel flow. Thus, once you have a target power level identified, you begin to hone in on the turbocharger size, which is highly dependent on airflow requirements.

Other important factors include the type of application. An autocross car, for example, requires rapid boost response. A smaller turbocharger or smaller turbine housing would be most suitable for this application. While this will trade off ultimate power due to increased exhaust backpressure at higher engine speeds, boost response of the small turbo will be excellent.

Alternatively, on a car dedicated to track days, peak horsepower is a higher priority than low-end torque. Plus, engine speeds tend to be consistently higher. Here, a larger turbocharger or turbine housing will provide reduced backpressure but less-immediate low-end response. This is a welcome tradeoff given the intended operating conditions.

Selecting the turbocharger for your application goes beyond “how much boost” you want to run. Defining your target power level and the primary use for the application are the first steps in enabling your Garrett Performance Distributor to select the right turbocharger for you.



Journal Bearings vs. Ball Bearings
The journal bearing has long been the brawn of the turbocharger, however a ball-bearing cartridge is now an affordable technology advancement that provides significant performance improvements to the turbocharger.

Ball bearing innovation began as a result of work with the Garrett Motorsports group for several racing series where it received the term the ‘cartridge ball bearing’. The cartridge is a single sleeve system that contains a set of angular contact ball bearings on either end, whereas the traditional bearing system contains a set of journal bearings and a thrust bearing




Turbo Response – When driving a vehicle with the cartridge ball bearing turbocharger, you will find exceptionally crisp and strong throttle response. Garrett Ball Bearing turbochargers spool up 15% faster than traditional journal bearings. This produces an improved response that can be converted to quicker 0-60 mph speed. In fact, some professional drivers of Garrett ball-bearing turbocharged engines report that they feel like they are driving a big, normally aspirated engine.

Tests run on CART turbos have shown that ball-bearings have up to half of the power consumption of traditional bearings. The result is faster time to boost which translates into better drivability and acceleration.

On-engine performance is also better in the steady-state for the Garrett Cartridge Ball Bearing



Reduced Oil Flow – The ball bearing design reduces the required amount of oil required to provide adequate lubrication. This lower oil volume reduces the chance for seal leakage. Also, the ball bearing is more tolerant of marginal lube conditions, and diminishes the possibility of turbocharger failure on engine shut down.

Improved Rotordynamics and Durability – The ball bearing cartridge gives better damping and control over shaft motion, allowing enhanced reliability for both everyday and extreme driving conditions. In addition, the opposed angular contact bearing cartridge eliminates the need for the thrust bearing commonly a weak link in the turbo bearing system.

Competitor Ball Bearing Options – Another option one will find is a hybrid ball bearing. This consists of replacing only the compressor side journal bearing with a single angular contact ball bearing. Since the single bearing can only take thrust in one direction, a thrust bearing is still necessary and drag in the turbine side journal bearing is unchanged. With the Garrett ball bearing cartridge the rotor-group is entirely supported by the ball bearings, maximizing efficiency, performance, and durability.

Ball Bearings in Original Equipment – Pumping up the MAZDASPEED Protegé’s heart rate is a Garrett T25 turbocharger system. With Garrett technology on board, the vehicle gains increased acceleration without sacrificing overall efficiency and it has received many rave reviews from the world’s top automotive press for it’s unprecedented performance.

Source by Honeywell Garrett

And here’s its Wiki site for Turbochargers:
Turbocharger - Wikipedia, the free encyclopedia







Supercharger 101

Getting more fuel into the charge would make for a more powerful explosion. But you can't simply pump more fuel into the engine because an exact amount of oxygen is required to burn a given amount of fuel. This chemically correct mixture -- 14 parts air to one part fuel -- is essential for an engine to operate efficiently. The bottom line: To put in more fuel, you have to put in more air.
That's the job of the supercharger. Superchargers increase intake by compressing air above atmospheric pressure, without creating a vacuum. This forces more air into the engine, providing a "boost." With the additional air in the boost, more fuel can be added to the charge, and the power of the engine is increased. Supercharging adds an average of 46 percent more horsepower and 31 percent more torque. In high-altitude situations, where engine performance deteriorates because the air has low density and pressure, a supercharger delivers higher-pressure air to the engine so it can operate optimally.

ProCharger D1SC centrifugal supercharger


To pressurize the air, a supercharger must spin rapidly -- more rapidly than the engine itself. Making the drive gear larger than the compressor gear causes the compressor to spin faster. Superchargers can spin at speeds as high as 50,000 to 65,000 rotations per minute (RPM).
A compressor spinning at 50,000 RPM translates to a boost of about six to nine pounds per square inch (psi). That's six to nine additional psi over the atmospheric pressure at a particular elevation. Atmospheric pressure at sea level is 14.7 psi, so a typical boost from a supercharger places about 50 percent more air into the engine.
As the air is compressed, it gets hotter, which means that it loses its density and can not expand as much during the explosion. This means that it can't create as much power when it's ignited by the spark plug. For a supercharger to work at peak efficiency, the compressed air exiting the discharge unit must be cooled before it enters the intake manifold. The intercooler is responsible for this cooling process. Intercoolers come in two basic designs: air-to-air intercoolers and air-to-water intercoolers. Both work just like a radiator, with cooler air or water sent through a system of pipes or tubes. As the hot air exiting the supercharger encounters the cooler pipes, it also cools down. The reduction in air temperature increases the density of the air, which makes for a denser charge entering the combustion chamber.
Types of Supercharger
There are three types of superchargers: Roots, twin-screw and centrifugal. The main difference is how they move air to the intake manifold of the engine. Roots and twin-screw superchargers use different types of meshing lobes, and a centrifugal supercharger uses an impeller, which draws air in. Although all of these designs provide a boost, they differ considerably in their efficiency. Each type of supercharger is available in different sizes, depending on whether you just want to give your car a boost or compete in a race.

Roots Supercharger

A twin-screw supercharger operates by pulling air through a pair of meshing lobes that resemble a set of worm gears. Like the Roots supercharger, the air inside a twin-screw supercharger is trapped in pockets created by the rotor lobes. But a twin-screw supercharger compresses the air inside the rotor housing. That's because the rotors have a conical taper, which means the air pockets decrease in size as air moves from the fill side to the discharge side. As the air pockets shrink, the air is squeezed into a smaller space.

Twin Screw Supercharger


A centrifugal supercharger powers an impeller -- a device similar to a rotor -- at very high speeds to quickly draw air into a small compressor housing. Impeller speeds can reach 50,000 to 60,000 RPM. As the air is drawn in at the hub of the impeller, centrifugal force causes it to radiate outward. The air leaves the impeller at high speed, but low pressure. A diffuser -- a set of stationary vanes that surround the impeller -- converts the high-speed, low-pressure air to low-speed, high-pressure air. Air molecules slow down when they hit the vanes, which reduces the velocity of the airflow and increases pressure.

Centrifugal Supercharger

This post has been edited by Dragondog: Jun 16, 2009 - 6:17 AM