folks in the house can u explain wat is meant by an engine being turbo charged and does it use a carburretor or an injector.pls a good writeup will be fine

bollingjoe:

folks in the house can u explain what is meant by an engine being turbo charged and does it use a carburretor or an injector.please a good writeup will be fine

Turbocharging became common in the early 70's, and was a way of making a "smaller" engine "larger". It's sole purpose was to increase power output, without "adversely" affecting fuel economy.

Basically, a turbocharger consists of 2 fans / turbines mounted on a common shaft.
The turbocharger is mounted upstream of exhaust gases, and the exhaust turbine was driven by these gases as they exited the engine.

Turbochargers are either oil or water cooled, or a combination of both.

The compressor side, often referred to as the cold side drew in cold air, and this was forced into the engine, via the intake plenum (fuel injected models) or the venturi (carburettor models), filling the cylinders.

The more air that was introduced into the engine, the more fuel could be burnt, and the more power could be achieved.

Compressing air however, gave rise to heat. In order to cool the compressed air, prior to it entering the engine, the air was passed through an intercooler, or chargecooler, increasing its density.

Cold air is denser than hot air.

The intercooler is usually a small, radiator-like assembly, usually made of aluminium.
It has an inlet and outlet pipe, and is fitted in series with the turbocharger and engine.
It is usually mounted at the front of the car, and the surface area allows it to cool the charge air being passed through it.

A chargecooler works in a similar manner, but rather than being cooled by air, has an external aluminium "jacket" around it.
Water or other cooling fluid is passed through the outer envelope, cooling the fins which are air cooled in an intercooler.

It's also worth noting, early turbocharged cars, running low boost, were not fitted with intercoolers, as light pressure turbochargers generate less heat than high pressure ones.

There are more sophisicated control factors that govern boost pressure.

A "wastegate" is the primary one.

This is basically an exhaust outlet - once a preset boost level is reached, a flap opens up, and the excess gases are dumped back into the exhaust system, exiting the motor, and bypassing the exhaust turbine, hence reducing "spool up", i.e, the turbocharger reduces speed, and hence boost pressure.

Wastegates can be integral with the turbocharger, or external.

Most turbo applications also include a "diverter" or "dump" valve.

These are mounted on the cold side, one end see's boost, and the other side is mounted in the air intake.

Once boost rises, and exceeds the preset level, a spring-loaded diaphram valve is forced open, and excess boost is vented back into the intake side.
The diverter valve also opens during decelleration, i.e between gearchanges. This is achieved via a vaccum pipe, off the intake plenum, and allows the turbocharger to continue spinning, reducing "lag" between gear changes.
The absence of the diverter valve, will cause the turbocharger to stall between gearchanges, as the throttle is closed, and the boost pressure has howhere to go.
In extreme situations, especially on high-boost cars, the turbocharger vanes have been known to shatter, or the shaft has failed.

The dump valve operates in a similar manner, though as the name suggests, the excess boost is not diverted back into the intake side, but is "dumped" into the atmosphere, giving the characteristic "pshhhhhhht"! between gear changes.

More here, see post #214:

https://www.nairaland.com/nigeria/topic-106528.192.html

Siena:

Turbocharging became common in the early 70's, and was a way of making a "smaller" engine "larger". It's sole purpose was to increase power output, without "adversely" affecting fuel economy.

Basically, a turbocharger consists of 2 fans / turbines mounted on a common shaft.
The turbo was mounted upstream of exhaust gases, and the exhaust turbine was driven by these gases as they exited the engine.

Turbochargers are either oil or water cooled, or a combination of both.

The compressor side, often referred to as the cold side drew in cold air, and this was forced into the engine, via the intake plenum (fuel injected models) or the venturi (carburettor models), filling the cylinders.

The more air that was introduced into the engine, the more fuel could be burnt, and the more power could be achieved.

Compressing air however, gave rise to heat. In order to cool the compressed air, prior to it entering the engine, the air was passed through an intercooler, or chargecooler, reducing its density.

Cold air is denser than hot air.

The intercooler is usually a small, radiator-like assembly, usually made of aluminium.
It has an inlet and outlet pipe, and is fitted in series with the turbocharger and engine.
It is usually mounted at the front of the car, and the surface area allows it to cool the charge air being passed through it.

A chargecooler works in a similar manner, but rather than being cooled by air, has an external aluminium "jacket" around it.
Water or other cooling fluid is passed through the outer envelope, cooling the fins which are air cooled in an intercooler.

It's also worth noting, early turbocharged cars, running low boost, were not fitted with intercoolers, as light pressure turbochargers generate less heat than high pressure ones.

There are more sophisicated control factors that govern boost pressure.

A "wastegate" is the primary one.

This is basically an exhaust outlet - once a preset boost level is reached, a flap opens up, and the excess gases are dumped back into the exhaust system, exiting the motor, and bypassing the exhaust turbine, hence reducing "spool up", i.e, the turbocharger reduces speed, and hence boost pressure.

Wastegates can be integral with the turbocharger, or external.

Most turbo applications also include a "diverter" or "dump" valve.

These are mounted on the cold side, one end see's boost, and the other side is mounted in the air intake.

Once boost rises, and exceeds the preset level, a spring-loaded diaphram valve is forced open, and excess boost is vented back into the intake side.
The diverter valve also opens during decelleration, i.e between gearchanges. This is achieved via a vaccum pipe, off the intake plenum, and allows the turbocharger to continue spinning, reducing "lag" between gear changes.
The absence of the diverter valve, will cause the turbocharger to stall between gearchanges, as the throttle is closed, and the boost pressure has howhere to go.
In extreme situations, especially on high-boost cars, the turbocharger vanes have been known to shatter, or the shaft has failed.

The dump valve operates in a similar manner, though as the name suggests, the excess boost is not diverted back into the intake side, but is "dumped" into the atmosphere, giving the characteristic "pshhhhhhht"! between gear changes.

More here, see post #214:

https://www.nairaland.com/nigeria/topic-106528.192.html

Oga Sienna ! I sometimes wonder maybe you are mechanic or a car dealer . Na you biko jare !

@bigfada
nope he is an engineering

on a more serious note, he is an ENGINEER.
a humble one at dat.

@siena
the way u explained this turbo charging thing and the workings is 2 ABSTRACT and COMPLEX for some of us
some of us dont know how a valve works and u are now talking of pressure releasing valve
Abeg easy no be every body be Engineer

@ Iceman: My apologies.

Let me know what aspect isn't clear, and I'll do my best to explain.