Can you explain what it adds to a normal gasoline engine ?

Turbochargers (aka turbo) use the heat from the exhaust of the car to add to the power of the vehicle. l dont know it any farther than that.

Does not it add more air intake?

It makes your cars fuel economy slightly worse.

a turbo works by drawing air from the exhaust. the air then goes through an intercooler which cools the air before it enters the intake. by forcing cool air into the air/fuel mixture you are actually burning more fuel at a higher temperature. this will show up as increased horsepower and significantly lower gas mileage.

When needed more power, turbo pushes more air/fuel mixture into the engine - the more fuel burnt, the more power. So within certain time, let is say, 1.8-liter engine with turbo gets the same amount of air/fuel mixture into the cylinders as 3.0-liter non-turbo engine. So roughly 1.8 turbo engine will have equal power to 3.0 non turbo.

Harry had the best explination. To add to his, all a turbocharger is doing is compressing the air ''before'' it enters your combustion chamber. By compressing the air entering your combustion chamber you're allowing more air and fuel to be combusted, and going by the simple principal, the more air and fuel you can get into the combustion chamber, the more horsepower you achieve.

A turbocharger (turbo) is a turbine which has two housings (one exhaust, one intake) with a rod connecting the two turbines. One side is connected to the exhaust manifold & uses the exhaust to spin the turbine. The expelled exhaust is run through the exhaust side of the turbo housing on out through the exhaust pipes. The intake side takes air through the air intake filter, & due to the different angle on the intake side is fins, the air is pressurized, blown through an intercooler (looks like a radiator) to cool the charged air, & into the combustion chamber. Increased pressure in the combustion chamber enables more air to be caught inside which creates a stronger combustion. Stronger combustion equals more power. Turbocharged cars have been modified for the increase in heat caused by the turbocharger, under high ammounts of boost, the computer adds more fuel to the mixture & retards engine timing to combat against detonation. By adding a turbo charger to a non-turbo engine u can increase horse power by 25-250% depending on the application & tuning. For example, The MkIV Toyota Supra TT comes stock with about 275hp. With a larger turbo, engine upgrades & tuning it is not uncommon to see 750-1000hp Supras. Heavy duty drag racers have been known to get 1500hp out of them. Motors do not last very long at 1500hp though. Turbocharged cars also benefit the most from minor upgrades like cold air intakes & cat-back exhausts.

They r also more fun.

Sorry Harry, u missed it a little bit. All of the exhaust goes out the tailpipe. The exhaust gases come out of the head(s) & spin a small fan or impeller. The turbo has two chambers. One for exhaust, one for intake. The exhaust gas exiting the engine spins the fan fast enough to make the intake side of the fan push air into the engine. Cold air & more air has more oxygen which makes more horsepower. The turbo just packs a bigger amount of air/fuel mixture into the cylinders. Turbos come in many sizes to fit almost any engine. They especially work well on diesel powered vehicles.

Some good . Here is what happens. A turbo forces more air into the intake system which means more horsepower. This does tend to use more fuel also as one tends to step harder on the gas pedal. However if you drive smart you can get decent mileage. l had an 86 AUD l 5000CS TURBO that averaged 22 MPG. IF you want to see for yourself try howthingswork.com. l have used this site to teach people in my company about cars.

how to increase power? air flow this can be done with a big engine [uses big fuel too] or small engine with on demand power increase [if the air is partly compressed before it enters the cylinders more air [substantially more] will flow through the engine ] & u only need the extra fuel under boost conditions.

that being said beware of the turbo buzz, it [the constant urge to be under boost conditions] this is hazardous to ur license as mere speeding tickets r replaced with a multitude of reckless driving citations.

By utilizing some backpressure on the exhaust of an engine, a turbocharger compresses the intake air & gives u the option of having more power.

If u never stomp on the throttle, the turbo will never compress the air very much & there will be little difference.

When u do open up the throttle, the exhaust increases & then intake flow increase (there is a slight time lag). More fuel & air r going through the engine so u develop more power.

So, yes a 2.0-liter with a turbo will have more hp than a 2.0, even a 2.5 without a turbo. Taken to the extremes done in racing, turbos can double, triple or more the hp of a base engine.

Turbos can be sized primarily to increase power & then u will get worse mileage (but go faster). Or they can be used to get a undersized engine up to a minimum level of preformance (and then they can increase mileage - the original 35 hp diesel Rabbits got about 50 mpg but 60-65 mpg with a turbo driven sedately).

How can having the turbo help ur mileage? By compressing & expanding the air in 2 steps instead of one, the process is closer to theoretically ''reversible'' & therefore closer to the theoretical maximum efficiency.

For a particular make & model, get data on acceleration, top speed & real-world fuel efficiency with & without the turbo. The turbo definitely adds cost & complexity. When properly designed & implemented, it can also increase performance & efficiency.

Hope that helps.