MOTORING CORNER : “What you need to know “Carburettors Vs EFI?”

A motor vehicle is may be termed as a wheeled vehicle whose momentum is provided by an engine or motor. The internal combustion engine is the most common motor choice, although electric motors or other types are sometimes used. Motor vehicles typically run on public roads. The rules of the road are laws or practices which all road users must obey; many relate specifically to motor vehicles some common types of which are, automobiles or cars, trucks or lorries, busses, motorcycles and motorised bicycles and some earth moving or engineering vehicles.

Friday, January 15, 2010

A motor vehicle is may be termed as a wheeled vehicle whose momentum is provided by an engine or motor. The internal combustion engine is the most common motor choice, although electric motors or other types are sometimes used. Motor vehicles typically run on public roads.

The rules of the road are laws or practices which all road users must obey; many relate specifically to motor vehicles some common types of which are, automobiles or cars, trucks or lorries, busses, motorcycles and motorised bicycles and some earth moving or engineering vehicles.

What is common in all these is the fact that, they all comprise of an engine (either internal combustion or electrical). 

However, our subject of discussion is mainly the internal combustion engine driven vehicles.  Under this category, we shall examine as to whether to go in for a "Carburettor” or "EFI” (electronic fuel injector) driven vehicle.
 
Many people have been arguing for and against one form over the other. I am here to offer my opinion along with facts.

I will admit that I am a little bias toward EFI, I will try to look at both sides of the coin as objectively as possible.  The Carburettors have been around for over a century. 

This is a device that, simply put, delivers the amount of fuel an engine needs in relation to the amount of air that is pushed through it by atmospheric pressure.  Carburettors work on a pressure-drop principle, when tuned properly for atmospheric and weather conditions, carburettors work very well.   

There are many types of Electronic Fuel Injection on the market today.  Basically, we have  3 major types known as: Throttle Body Injection, Port Fuel Injection, and Direct Fuel Injection.

All of these systems are controlled by very similar microprocessor (the so called computer) systems and related sensors. 

Throttle Body Injection is the simplest type of EFI and the closest to carburetion in operation.  Fuel is injected above the throttle blades by one or more fuel injector nozzles.  Both fuel and air are carried throughout the entire intake tract.

As for the Port Fuel Injection, this is the most widely utilised form of injection today.  Fuel is injected at each intake port, usually at the cylinder head and intake manifold.

Only air travels through the intake tract until it reaches the point in which fuel is injected.  This method allows a wide variety of intake system designs to be explored and utilised depending on application, thus making super- and turbo-charging extremely feasible.

The Direct Fuel Injection is a new technology.  This system utilizes injectors similar to diesel engines in which fuel is injected directly into the cylinder.

Obviously cost is high due the custom cylinder head configuration and high-temperature injector required.  This system is not so widely used yet, because, performance the levels of attainable power potential are still being worked upon.

The real question is which is better?  Well, this depends on a lot of factors.

For one, what do you do with, and how do you drive your car?  Obviously, if you race a vehicle professionally in which rules are involved that restrict the type of fuel delivery that can be used, you have little choice.

The big question has always been which delivers more power?  Well, this too is a good question.

Carburettor proponents argue that carburettors make more power over port injection because the fuel helps "cool” the intake manifold.  If this were true, what about Throttle Body Injection?

There is little or no evidence to prove that carburettors out-perform port EFI on identical engines and vice-versa in controlled conditions. Carburettors will work great in ideal weather conditions and areas of the country which see little climate changes.  Regrettably, there are rarely ‘ideal’ conditions.

This leaves you no option but to change jets and tune your carburettor to the changing weather conditions as the day goes on.  On the other hand, EFI systems automatically compensate for changing conditions.
 
If you don’t mind drivability problems when the engine is cold or the humidity is high then carburettors are for you. 

Simply put, no carburettor can do what a feedback EFI system can do compared by cost.  There is no carburettor that you didn’t have to tune to offset changing conditions.  These changes require carburettor disassembly in most cases. 

EFI can compensate for most changes automatically; those that cannot be automatically adjusted can be easily reprogrammed by PC or Laptop computer in just minutes without getting your hands dirty.

There you are, the choice is yours!
 
motoringcorner@live.co.uk