| LEARN TO RACE AND WIN PART 1, BY FRANK MUNROE AKA DR.DWARF |
(original
article http://www.dwarfworld.com) |
|
Winning
starts at home. You cannot win at the track if your car is not prepared
to win. Preparation is the key to standing in the winners circle on Saturday
night. |
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A-Arms Most dwarf cars have some kind of tubular upper and lower A arms. The tubular A arms usually have rod ends and ball joints to attach them to the chassis and spindles. These rod ends and ball joints should be checked for wear and straightness. If the rod ends are worn or bent, replace them. Check the ball joint shaft to make sure it is not bent. Move the ball joint through it's motions to check for binds. You should have a smooth motion. If not, it needs to be replaced. * Steering Check your steering shaft and steering u joints. They should have little or no play when moved side to side. Too much play can cause a delay in the steering action which can cause the driver to oversteer or steer back and forth to compensate. The steering motion should be smooth from all the way right to left. Check your steering box. If your car has a chain and sprocket steering quickener, check the chain and gears for wear. Worn gears or chains can cause the same steering problems as mentioned with the U joints. There is also the possibility the chain could break, leaving the driver with no steering control on the track, leading to a wrecked race car. If your car is a rack and pinion steering unit, it should be cleaned and checked. Before removing the rack from the car, turn the steering wheel right to left. Does the rack feel smooth? If not, check to see why. The rack should steer smoothly with no binds or rough spots. Once the rack turns smooth with no binds, remove it from the car and clean it. Check the shaft for rust or chips in the teeth. Clean and relubricate it. If you have an aftermarket rack check with the manufacturer for lubrication recommendations. Don't forget to check the steering wheel quick disconnect. The part is often overlooked and can cause big problems if it fails. Spindles and Hubs: Remove the hubs from the spindles, then remove the bearings and clean them. Spin the bearing in your hand and make sure the bearing turns free and has no rough spots. If the bearing feels rough, replace it. Grease the bearings and reinstall into the hubs. On your spindles, look for bent shafts or cracked welds and check the bracket that attaches the steering to the spindle. This bracket may not seem important, but it can be the key to a well handling race car. This bracket has a big affect on the bump steer and ackerman steering. There are a lot of opinions on this topic and I could talk about that all day long, but let's just say that the slight angle changes on the steering bracket can really impact how your car is handling. Motors: Hopefully, while you had your car apart, you sent your motor to get freshened. I said freshened, not enlarged! One of the biggest misconceptions I hear people say is that you need a big motor to win. With race track for Dwarf's mostly being 1/4 mile or smaller, in most cases, too much power will just get you in trouble. The key to going fast is to have usable horse power. If you paid attention to the article and worked on your race car, checking every part to make sure things are as free as possible and not robbing horse power, you may feel like you got a new motor come race day. A properly handling car with a good driver will outperform a big motor in a poor handling car, anyday! Spend your money on the right components that will enhance your current motor and chassis. Before you ever consider buying a new motor, make sure your have a good set of carburetors, and a good header and cooling system. Good carbs can add horse power to your current motor. A tuned head and a good cooling system can make it all come together. If your motor runs hot, it will cost you horse power. Now that the car and the motor are taken care of, let's set up the chassis to go racing.... Set Up: Now that the car is on the ground, find a level spot in your shop to perform the set up.The first step is to set the air pressure on the tires. Depending on what tire your club uses, that will determine what the tire pressure should be. The wheel can also effect the tire pressure. If you run bead lock rims, the tire pressure can usually be run lower than a non-bead lock rim. Since most of the country has gone to a Hoosier Tire rule with a 7" or 8" rim, with no bead lock allowed, I will concentrate on that tire/wheel combination. If your club runs something different, adjust your tire pressure accordingly. Dirt Track: Right front: 11 lbs. Left front: 10 lbs. Right rear: 11 lbs. Left rear: 10 lbs. Asphalt Tires: Right front: 19 lbs. Left front: 16 lbs. Right rear: 18 lbs. Left rear: 16 lbs.Just a couple of things to consider when setting pressure...Rough tracks may require higher tire pressure to keep the tire from coming off the wheel. The type of air you use out of a air compressor can effect tire pressure. If you use air of out of a compressor, the tire pressure will increase during the race. This increase depends on how hot the tires get. Normal increase is between 2-6 pounds. Nitrogen in the tires instead of air will not be effected by the heat and very little tire pressure change will occur. Keep in mind that 1 lb. of pressure can change the way a car handles. Now that the pressure is set, square the rear end to the chassis. Some manufacturers build in squaring marks on the frame. If your chassis is equipped with these marks, use them to square the rear end. If not, then take a measurement from the middle of the lower A arm to the center of the rear end. Set both sides of the car at 73" wheel base. Once the rear end is square, take a measurement from the center of the rear end to the center of the lower ball joint. Moving only the lower A arm, set the wheel base at 73". If you have trouble achieving this due to non-adjustable lower A arms and have to move the rear end, move it evenly on both sides. This should at least keep the rear end square. If you have trouble getting a square measurement, no matter what you do, something is probably bent. Check your A arms and rear end for straightness again. Keeping the car square is very important, especially when it comes to sorting out handling problems later. Now set the side to side measurement for the rear end. Start out with even measurements. Set the Ride Height: Check with the manufacturer of your chassis to get height recommendations. Usually the chassis was built to work at a certain height with the other suspension. Most dwarf cars are designed to run between 5" to 6 1/2". The chassis's that I build and run have been designed to run a frame height of: Dirt: left front: 6" right front: 6 1/8" left rear: 5 3/4" right rear: 5 7/8 Asphalt: left front: 5 3/4" right front: 6" left rear: 5 1/2" right rear: 5 3/4" Now that the chassis is square and the frame heights are set, it is time for the caster and camber on the front end. To do this, you will need a caster/camber gauge. If you don't have one, borrow one. If you can't borrow one, buy one. This is a very important tool to have. Checking the caster/camber on a regular basis will be the difference between running up front and falling behind. Check with your chassis manufacturer for setup recommendations. Here are some recommended caster/camber settings: CASTER: Dirt track: left front: +3.0 degrees right front: +3.5 dg. Asphalt: left front: +3.0 degrees right front: +4.0 dg CAMBER: Dirt track: left front: +1.0 degrees right front: -3.0 dg Asphalt: left front: +0.5 degrees right front: -2.5 dg Your next step is to set the toe out. This may vary from car to car depending on how well your front end was designed. The less bump steer your car has, the less toe out you will need. A basic rule of thumb is the smaller and tighter the track is, the more toe out you will need. So keep in mind, the toe out will need to be changed to accommodate different size tracks. Smaller tracks, more toe out, bigger tracks, less toe out. Start out with 1/8" to 1/4" tow out. This will work on both dirt and asphalt. Pay close attention to tire wear on the front tires at the inside and outside edges. This will give you an idea if you need more or less toe out. Scale the car: Scales are an important tool to have. If your budget allows, buy a set of scales. they can cost from $1000.00 and up. If this kind of cost is out of the question, don't worry. Go in with a couple of buddies or get your club to buy a set of scales. Also, check with your local speed shop or one of the late model teams in your area. they will usually offer chassis set up and have a set of electronic scales. They may charge you for the service, but it is well worth it. The first thing to consider when putting the car on the scales is total weight. Most clubs have a minimum weight rule of 1000 pounds. Check your local rule. Weigh the car with and without the driver. How close are you to the minimum weight? If you must add weight, start with the weight on the left side of the car. Try to keep the weight between the wheel base of the car and behind the driver. Now with the driver in the car, record your cross weight, left side weight, rear weight and corner weights. Suggested Weights: Dirt tracks: cross weight- 48.5% to 51.0% Asphalt tracks: cross weight: 51.0% to 52.5% left side: 51.5% to 52.0%left side: 54.0% to 57.0% rear weight. These weights are weights that work well on M&M chassis but may not be exactly what you want. Check with your chassis manufacturer. Don't be afraid to try new ideas. That's how you find out what works. Good luck with these ideas and If you have any questions, e-mail them to Dr. Dwarf located at www.dwarfworld.com Frank Munroe aka Dr. Dwarf |