An overview of induction kits
Their business and the theory behind them, as induction kits are most likely one of the most popular modifications for car tuning projects we thought we should add a introductory article to describe what they are.
An induction kit is fairly simply an air filter. Most cars have air filters mounted in an air box. These filters are generally constructed of paper which filters out the particles from the air and prevents these from getting into the engine. The airboxes are designed to reduce the noise of the engine and have various vanes and angles cut to maximise this noise reduction.
Because the air is not really flowing freely through the filter there is potentially a loss in power due to the turbulence due to all that sound deadening. To make up for this loss of power the air filter surface area is significantly larger than the intake tubes so manufactures have effectively closed the gap between, noise reduction and gratifaction.
When it comes to car tuning noise reduction is often the last thing on peoples mind. Swapping out your restrictive air box by having an open filter helps to enhance the flow of air in to the engine and fully releases the induction roar, a noise linked to tuners cars the world over.
The induction kit is quite simply an open air filter shaped like a cone, dome or tube.
So it would appear that induction kits can be a win/win situation. There are some downsides, however. As being the filter is sited inside the warm engine bay it will suck in warm air which carries less oxygen. Thankfully after a mile or so the air temperature within the engine bay is much reduced and closer to ambient temperatures. Fitting a cold air feed pipe taking air from outside the engine bay will help to counter this problem.
Engines with induction kits fitted typically begin to see the power gains quite high in the RPM range. However low end power can be compromised. In small engines the outcome of an induction kit can be a noticeable loss of low end power. If you want to use the top end of the RPM range at all times, like you would in a race environment, but on the street this is just not viable, this is fine. Fuel usage would be much higher and you will be creating a noise nuisance to your neighbours.
Induction kits flow superior to paper elements partly mainly because they do less filtering. Induction kits continue to be efficient filters but they are not going to be as good as an OEM paper filter.
Do induction kits always add power?
NO – typically power gains are toward the best end from the RPM range and some engines will show an electrical loss, especially low down.
Do induction kits add fuel economy?
So round town you could notice a small improvement in MPG nevertheless the induction roar promotes a heavier driving style which negates this, by sucking in warm engine bay air the engine will make use of less fuel. Engines could be a little more efficient with induction kits so pull in more air. This generally means you will get more power from your fuel but if you adjusted your driving style, to use less throttle and settled to your previous power figures, you will get improved mpg with induction kits.
Are all induction kits a similar?
No, quality varies considerably. We recommend filters that happen to be using a cotton gauze filtration medium. Some kits come with high flow air air and boxes intakes designed particularly for a car and those will usually out perform basic filter only kits.
Are induction kits hard to fit?
Induction kits are very easy to fit. You may need to cut a pipe or two but a majority of kits might be fitted in 4 minutes with just a screwdriver.
I fitted an induction kit and I have flat spots?
Wait for quite a while. Modern engines may need to get used to the new air-flow characteristics. They will likely auto trim the fueling based on lambda readings. If after a tank of fuel you still get flat spots then you can examine your fuel delivery. Running lean can be a problem and several have noted that fitting a sports exhaust will further improve things.