Many of today's superstars of racing had beginnings in karting, so you are in good company if you've decided to become a karter. Prior to hitting the track for the first time, though, there are some things you should learn. While karts are mechanically very simple, there are several tips that will make your first forays onto the track more enjoyable.
The ToolsFirst, you will need some tools, but let's not go overboard. In terms of handtools, you will need 7 to 12 different wrenches and/or sockets. Go from the front of the kart to the back and write down the sizes of the nuts and bolts. If the kart has an American-made chassis, you will most likely find you need 71/416, 11/42, 91/416, and possibly 51/48 wrenches and corresponding sockets. For a kart of European manufacture, you will need the correct metric tools.
Karts also have a good number of hex key bolts, commonly called Allen bolts, so you will need several hex key wrenches. I would suggest the common right-angle wrenches and several T-handle wrenches. A common screwdriver and a Phillips screwdriver will be handy, although not always necessary. Safety wire pliers might be needed as well. You'll also need a chain break sized for the chain you are running. Karts have four different-sized chains, and your kart shop will be able to help you with the correct size for your application. A pair of needle-nose pliers and a set of side cutters will also come in handy.
With a little planning, you can save yourself a good bit of time and money by understanding your needs. You do not need entire sets of tools, but you'll need several of these and a few of those. Granted, sometimes you can save money by buying tools in sets, but you need to determine what you actually need. Remember that those extra tools may look cool in the store, but not so cool when you have to lug them around or when you need a specific wrench and you have to sort through a whole set to find what you want. Very often, time is a critical component in your race program, not just on the track, but off the track as well. The key is to remember that you do not need to transport sets of tools to the track; take only what you need, and nothing more.
You will need a source of compressed air for race day and for maintenance off the track. I suggest a simple air tank that can be purchased at any auto parts store for less than $35. A small air compressor can be purchased for less than $100 at any home improvement store. I have also seen small inexpensive air compressors at some of the larger chain auto parts stores in the same price range. At the track, you will see some racers with large Nitrogen K bottles. This is way more than you need to start. The cost is very high and the transportation issues outweigh any advantage this type of compressed gas may have for your current needs.
Buy a quality air pressure gauge. It is a critical part of your tuning arsenal. I would shy away from the digital type at first, due to the cost involved and the fact that they are battery powered. You will have too much on your mind to be concerned with keeping a spare battery for your tire pressure gauge when an analog gauge will work great. The range of pressures you will be dealing with in 99 percent of karting is from 9 to 20 psi. You want a gauge that places this in the middle of the range. A 0-30 psi gauge will be exactly what you need. The display should be in no less than 11/42-psi increments.
It is a wise investment to purchase a kart stand. While not 100 percent necessary, a stand makes working on the kart much easier on your back and knees. Prices range from $30 for a simple folding stand to well over $100 for a rolling stand.
Get two small fire extinguishers. Attach one to your kart stand, and place one in your trailer or tow vehicle-just make sure one is nearby if needed. Remember, you will be transporting fuel, so you need to take every precaution possible. The cost of two fire extinguishers is much less than the cost of visiting a burn center or replacing all of your fire-damaged equipment.
Prior to ever hitting the track, you need to check the machine and make sure that it is ready to race. It's helpful to have an experienced friend help with this, but even if you are flying solo there are some things to look over. Place the kart on the stand and we will get started.
Chassis AdjustmentsA kart might appear to have very limited adjustments, but the opposite is true. On the front end, you can adjust caster, camber, toe-in, toe-out, ride height, and track. Some karts have optional spindles to change the turn-in rates and the position of the axle in relation to the kingpin. The control pedals are adjustable to accommodate different drivers. The front bumpers are often adjustable to either stiffen or soften the chassis. Those are just the mechanical adjustments.
With tires, the variables include the different compounds within one brand and between tire brands. The selections will boggle your mind and challenge your wallet. The same is true of the wheels, as you have various types that can be used as tuning tools. Some wheels are made of aluminum that has been spun and then welded together. There are also cast-aluminum wheels, and even magnesium wheels are available-if your budget can handle them. Spun wheels are not as stiff as cast wheels. Do not underestimate the importance of the wheel as a tuning tool. Depending on the condition of the track, you can use the wheels to adjust the amount of grip the kart is experiencing.
Moving from front to back, the next adjustment will be the steering column. On most karts, you have the ability to adjust the height and angle of the steering wheel, and you gain even more adjustment with the addition of longer and shorter columns. You can buy different hubs (angled to provide a different feel and leverage inputs) to mount the steering wheel to the column.
Next is the seat, which we can move forward and backward to accommodate the driver. We can also move the seat up and down to change the center of gravity, and side-to-side and front-to-back to affect the weight bias and crossweight. The angle of the seat is also adjustable. All it takes is a drill and a little time.
The adjustability in the rear of the kart is no less than the front. We can change the axle wall thickness, the axle diameter (a very major change), and the rear width or track. The wheels and the tires are also adjustable. The hubs that attach the wheels to the axle are offered in different lengths to change the stiffness of the axle. In addition to these adjustments, we can add or remove bars to the frame to affect the stiffness of the chassis to match the track conditions on any given day. Let us not forget the engine-how and where it is mounted within the range of adjustment provided on the frame is something else you can adjust. Different engine mounts can place the engine farther out or closer in to change the weight bias. So, in addition to front-to-back engine placement, you have side-to-side placement.
Chassis DynamicsAll of the adjustments on the modern kart are there to aid the tuner in making the kart turn. On a Sprinter and a Road Racer, we are dealing with right and left turns. The Speedway kart involves left turns only. Nevertheless, the goal is the same: make the kart turn with as little steering input as possible and accelerate off the turns and down the straight. Adjusting the kart to turn is sometimes very difficult.
In general terms, to get a kart to turn you have to unload the inside rear tire. The job of the front tires is to unload the inside tire. If you don't unload the inside tire, the kart will push like a dump truck.
Here's a small illustration of the importance of unloading the inside tire. Have a buddy sit in the kart while you become the engine, pushing the kart several feet and asking your buddy to turn the wheel. Just as soon as the steering wheel is turned, the effort to push the kart will almost double. This is the same type of difference in force the engine will experience on the track when you are turning. Karts have a solid rear end, in that both tires are attached to a common axle and there is no differential to assist in turning. This increase in effort is the result of the inside tire traveling in a smaller arc and being forced to scrub while the outside tire is traveling in a larger arc without scrubbing. This lack of a differential is what makes tuning the chassis so important. So, how do all of the various adjustments help you reach handling nirvana? I wish the answer was a simple one but, in all truthfulness, it depends.
The modern kart is wider than it is long from a wheelbase perspective, making karts very twitchy and responsive to driver input. Karts, in fact, are about the most responsive racing vehicles to be found.
We have determined that the goal is to get the kart through the corner without a great deal of input through the steering wheel. When the front wheels are turned, as our buddy in the above example illustrated, the force or power required to drive the kart forward goes up significantly. So we need to make sure that the inside tire (the left rear if we are turning left and right rear if we are turning right) unloads and allows the kart to turn with as little effort as possible. Unloading the inside tire does not entail picking it up 3 or 4 inches. The amount of load removed may only be the thickness of a sheet of paper. Remember we are talking about very small increments.
Getting StartedMounting the seat is the first critical hurdle you must negotiate in setting up your kart. It is critical that the seat you select fits the driver. It has to be snug without being overly tight. However, if it is too loose, it has the potential to cause serious injuries. Broken ribs are a very common karting injury, and the seat plays an important role in preventing these injuries. The seat needs to hold the driver in by his sides and by his rear end and upper legs. Spend some time sitting in various seats before making a final decision on the seat or seats to be used. At the track, ask if you can sit in karts belonging to others, and develop a feel for the brand and size of seat you find the most comfortable. Keep in mind that there is a good deal of variation between seats of the same manufacturer. The molds to make seats are different, and if a medium seat at the track fits great, that does not mean the medium at the kart shop will fit. Try it before you buy it, because as soon as you drill holes in the seat, it is no longer something you can return to the kart shop with ease.
This seating position will provide the foundation for your setup. In the not-too-distant past, the standard weight bias from front to back was a split of 40 percent on the front and 60 percent on the rear. But with karts evolving and tires becoming better over the years, splits are now closer to 50/50. On dirt, there is still bias to the back, but the pavement karts are more equal than not. For a beginner, 40 to 45 percent on the front and 60 to 55 percent on the rear is a good place to start. It is not that difficult to drill some extra holes in the seat to facilitate changing the weight distribution at the track. This can be done when you are setting up the kart at home in the shop. This makes it much easier to make this type of change at the track. You will not need a set of electronic scales, as four bathroom scales will work just fine as you begin your career.
Many karts come with setup sheets that outline the best place to start with adjustments. Lacking a setup sheet, beginning racers should talk to other racers. One word of warning: Mount the engine and all of the related engine components first. Do not mount the seat first, as the seat mounting position, to a large degree, is dictated by the engine mount.
First Day at the TrackIdeally, your first day at the track will be on a practice day. Here are a few final checks:
* Make sure all of the nuts and bolts are correctly torqued and all of the steering-related fasteners are lock-wired or cotter keyed.
* Make sure the fuel lines (if you have any) are not leaking and all of the connections are mechanically secured with zip ties or hose clamps.
* Check the tires for proper inflation. I would suggest that you run the pressures a bit higher than normal (4 or 5 psi). A kart that is loose is easier to recover than one that is flipping.
* Prior to taking the kart out on the track, it is a good idea to walk the track and get a look at the layout and make sure you are familiar with the procedures for entering and exiting the track. Once everything is set and you have all of the required safety equipment, it's time to head out on the track for your first outing.
Push and Loose Push, or understeer, means that as you turn the steering wheel, the kart keeps going straight and requires an excessive amount of steering input to turn the kart. The inverse is true with loose, or oversteer, when, as you start turning into the corner, the rear of the kart starts to slide and you are suddenly countersteering to keep from spinning out. These conditions can be caused by several things-old tires or tires with the incorrect compound, track conditions, and more.
The driver can also cause handling issues by using too much or too little steering input. Prior to pointing to our driver for causing the problem, we will look at how we can adjust the kart to help the situation. Let's start with a loose condition. Try lowering the tire pressure to get more grip (remember, we started with too much air pressure). If that doesn't work, then move the rear wheels closer to the frame. This is accomplished by loosening the hubs and sliding them down on the axle. Once you have done this, tighten the bolts and try again. We could also move the front wheels out. Both actions help transfer weight off of the inside tire as we turn the steering wheel. Remember that tuning is a process, and you need to be diligent about keeping records and being a good experimenter.
From a general perspective, if the kart is loose or oversteering, you narrow the rear and widen the front; if the kart is pushing, you will widen the rear and narrow the front. If the driver is not the cause of the handling issue, push is caused by too much grip and loose is caused by not enough.
Something else you may experience is the car hopping or porpoising through the corner. This is usually a result of the track developing too much grip. Many of the newer karts have chassis adjustments that will help diminish this issue. Sometimes you can add additional chassis braces to stiffen the kart. Another method of adjusting the kart when there is too much mechanical grip is to add air pressure. It is amazing how adding 2 or 3 psi to each tire makes the kart respond. Changing from a spun wheel to a cast wheel will also affect how the kart responds in high-grip situations.
What you need to remember is that karting is experience based. As you log more laps and improve as a driver and tuner, the range and the degree to which you make adjustments will change. At first, the adjustments will tend to be very large, but they will become much finer and more incremental as you gain experience.
Do not be afraid to experiment. Make some big changes and see what happens. Whatever you do, keep notes and document all changes and setup variations. Keep track of the weather and changing track conditions. Remember, there are no absolutes. Be daring with setups, but remember there is a person sitting in that seat and you need not take any risks that will endanger the driver, other drivers, or people around the track.