Dirt Kart Racing Downunder

Dirt kart racing is alive and well in Australia, and each year more people are discovering the fun of “Doing it on dirt”. Most States of Australia have Dirt Kart clubs operating in some form.
To find out if there is one located near to you, contact the State Office of an organisation listed in the Phone Book, or for your nearest Australian Independent Dirt Kart Association club, contact the head office in Adelaide. If there isn’t a dirt kart club within easy reach, then get one going. If you have access to a speedway track, then you have a starting point to build a club. All the help you need is available from the relevant association.

TYPES OF DIRT KART RACING

The two main configurations of dirt karts racing in Australia are (1) Speedway and (2) Sprint Kart. The Speedway kart configuration has been copied from the American model with karts having bodywork on both sides of the kart. The bodywork provides some extra protection for the driver as well as giving the karts that individual look. the Sprint Kart configuration has the more traditional kart appearance with nassau panels and side pods or side knerf bars the only external protection allowed.
If the club is affiliated with the Australian Karting Association or AKA, they are most likely to be using slick type tyres, although grooved and treaded dirt tyres are allowed under some circumstances. If the club is affiliated with The Australian Dirt Kart Association or AIDKA, they are most likely to be using the American Burris treaded dirt kart tyre.

DIRT TRACKS

Most Australian dirt kart tracks are a water bound clay mixture while in areas with water supply problems some tracks are still oil soaked. The oil soaked method of preparing tracks is not popular with the environmental authorities and tends to get your kart and equipment dirty also. The actual consistency of the track surface is not all that important providing the surface packs reasonably tight. To keep track construction and maintenance costs down, the use of local materials is the best way to go.

MAINTENANCE

While on the subject of keeping your kart clean, (and that’s the way it should be before each heat) the best way to stop the dirt and clay from sticking is to spray the frame with CRC before racing. Most dirt will rub off with a cloth, or at the very least will be easier to remove with a garden hose at the end of the day.
The kart should be stripped regularly to clean all parts, especially bearings, and that should also make you aware of any parts that may be worn or about to break. Better to replace worn parts in the workshop than in the middle of an important race meeting. The more effort you put in between race meetings will inevitably save you money, and such things as soaking the drive chain in oil between meetings will prolong the life of the chain and sprockets.

DIRT KARTS

Only a matter of four or five years ago the dirt kart people used any old worn out sprint kart. Today, there are specifically designed dirt karts on the market to cater for the wide range of adjustments needed for the different surfaces encountered. The new breed of dirt kart is very square, with track and wheelbase of similar dimensions. On dirt there is also the need to keep all four wheels on the track, so the chassis must flex, with hard cornering and G forces approaching that experienced on bitumen.

DIRT TYRES

The majority of dirt karters competing in Australia race under the A.I.D.K.A. banner and use the American treaded “Burris” dirt kart tyre. The Burris is a much heavier tyre than the equivalent slick tyre and is softer and more flexible. Depending on driver weight and track surface, most run between 6 and 10 lb of pressure, around the same as is used for slick tyres on the dirt. It is more important to maintain the tyre to track contact with slick tyres, so they have a harder sidewall to keep the tyre shape under hard cornering conditions. The AKA clubs use any SL tyre in the restricted classes, while the AKA Speedway clubs also allow tyres to be hand grooved.

KEEPING THE DIRT OUT

The secret to economical dirt karting is keeping the inside of the engine clean. You will have less engine rebuilds if you can keep the dirt and dust to a minimum as this is a major source of wear on the bore and bearings. The best method to achieve a dust free engine is to use a good quality and well-oiled foam filter secured to the carburettor inlet. I repeat the filter must be oiled, and have a couple of spares to use during a race meeting in case you end up in a sand trap. If you belong to a CAMS or AKA club, you will also have to use an inlet silencer or football. These are only used to cut down the noise from the carburettor inlet, and a foam filter is still needed to keep out the dust. The next most important place to keep dirt free is the brake assembly. The best way to keep this area functioning is to deflect the water and dirt with a piece of plastic such as a number plate. These are strapped on an angle to the front corner of the brake assembly using cable ties.

ON RACE DAY

Now that you have a few of the basics under the helmet, the idea is to get in five good heats and a feature race before the end of the day. The biggest problem encountered when you start out racing on a dirt track is to get past the first corner without spinning out. The idea is to take it easy for the first couple of meetings as you have a lot to learn. With a bit of luck if you set up the kart in a reasonable fashion you should be able to finish three heats at least.

CHANGING TRACK CONDITIONS

The hard part about racing on dirt tracks is reading the changing track conditions from heat to heat. The changes are brought about depending on when the track is watered and how many classes have run since the last watering. If you are racing on a loose surface track, the chances are you will have to contend with the occassional track grade also. Use the rolling laps to check the track surface for wet, dry or rough areas and try to avoid them.

DIRT KART SET UP

The two most popular methods for setting up dirt karts are, (1) in-line, and (2) staggered. The in-line method has the left front wheel lined up with the left back wheel, and if you move one, you move the other. The right side is the same. The staggered method has the left front wheel out, and the left rear wheel in. The right front wheel is in and the right rear wheel is out. With this method only one wheel position is changed at a time to correct any problems on track. The amount of difference is only about 10-15mm at a time, but changes will be essential during the course of a race meeting.
To counter oversteer try moving the outside front wheel in and with understeer move the outside front wheel out. The back end of a dirt kart must be flexible, with more flex needed as the track becomes dry and grippy later in the day.
Practice sessions are generally not easy to get on a dirt track with the necessity to water a prime reason. DO NOT run a kart on a dry dirt track as this damages the track surface as well as your engine. Take the advantage to get in some practice when you can, and try some of the adjustments mentioned. You can only make a mistake if you do nothing.

A FUN WAY TO GO

Go along to a dirt kart meeting, you will be surprised at the relaxed atmosphere. “Dirt Karters Have Fun” is the general feeling around the tracks, and there is no safer way for a youngster to learn the skills of driving and controlling a kart in a slide.