Stop Pounding Tin

Some sections may go more into detail than others based on what we feel is common knowledge. If we find that we get a lot of questions in a section that was lightly covered then we will go back and add to it.  

Ok let's start out by clearly stating I hate pounding tin ! I truly feel that is a general consensus. What really bothers me is at most tracks it's the same driver or few drivers in every class creating all this work . I am also saying that yes not every driver is gonna be the best in such class. How ever when those same cars are a weapon week after week after week lets face it they need help !
 
Now on that note lets make another thing clear, if you have drivers and other crew members trying to help you out and you "think they are doing it to mess with you" but you keep going out week after week tearing equipment up yours or not you need to start doing something different ! This is no lie I have heard this from a driver after his 7th week in a row of wiping out  half  the field and the front half at that because by the time the leaders got to him on the 5th lap he was still in the way and had know clue, he gets out of his car after being towed in and says " i cant believe these non-driving bastards wrecked me again this week they need to learn to f*cking drive" ! Now im sure i am not the only one who has ever seen this. So here is my thoughts and how i think we can help this situation out . Lets have a place where we can have credible info on setting up your ride. Drivers, fans, car owners and whomever else, this can only benefit all of us ! The money wasted and the fans not being able to see a good race sucks for all of us involved.

What i would like to do is lay down basics in this section and yes i will keep adding to it. I would like to involve some of the car manufacturers and people in our sport that will lead us in the right way. Basics are basics and when we get to a section were what we might do different say from a Bicknell Chassis to a Bloomquist Chassis we will try to elaborate more on the different deals. So as i start this little journey please keep in mind it is an on going effort and we will get the basics out there first. 

First things first. Go to your chassis manufacturer and get a set up sheet for that chassis. Ask "them" for advise on tweeks for the track you want to focus on. Take lots of notes, i can not stress to you how valuable notes can be !

Now that we have our set-up sheet from our car manufacture lets talk about scaling the car. We want this to be accurate every time we scale the car and i'm sure you have heard people talk about this , consistency is the name of the game . So with that being said you want to go through the same process every time you put your car on the scales . Some teams have a lift and some use a single jack and some even have drive on scales. When working on your car there is nothing like having a shop car lift. You can pick the car up put the scales under it and let it back down and start the process , however there are setbacks (hence the reason scale company’s are making side sliders ) to this that a lot of us know already and one of them is each time the car is lifted and set back down it seems to move. Most teams with a 3 link suspension will tell you it's a pain because every 3rd time up and down the rear of the car has to be slid back in position plus it seems as though the scale is always getting pinched . Jacking one tire up at a time and putting scale pads under that tire can also play havoc . So hear is the deal I find that most teams prefer to use, drive-on scales.  Driving on scales seems to be the way to go for the least amount of problems . Even if you have a lift you will find that putting a car on scales were you can roll the car on and off the scales to make adjustments will save you a lot of problems and keep you more consistent . There are good benefits and bad as well but over all this seems to work the best. When you set up your scales it is a great idea to do this in the same spot every time. You will want to make sure the scales are level on all four corners, this does not mean just the scale pad itself . This can be done with a transit or water level and what ever method used make sure all four corners are the same. There are many ways of doing it to keep it accurate as possible and thats the one thing you want every time. Once your scales have found a good place to be you want to mark those spots so the scale can clearly be seen if it has moved. Some have used anything from paint to duct tape. Even if you have a permanent place in your shop to scale the car it is still a good idea to mark these spots were the scale pads sit. Here is a link to a very good system (Link Here ). If you know a carpenter with some good skills you can have some built just make sure that when building them make sure the design does not let the scales flex at all on your ramp system . The other thing I would point out is when building a set of these make sure that when you roll your car back to make adjustments that the cross members for support are not going to be in the way of jacking up the car. You dont want to be jacking the car up and down on the scale pads themselves so rolling the car back of the scales and jacking it up is key and having access to get to the jacking points is necessary. If you have to roll the car on and off a few times you will also need to reposition  the car as it is going to want to turn on you, unless you are setting it up to go strait lol. Before pulling the car on the scales every week you can check to make sure the scales have not moved as to keep you in that being more consistent mode. And a real quick note here is that if you are using a tie-down shock on any corner of the car it is well advised to take it off and replace it before pulling on the scales and setting up your car (this will be explained in a later part) . The other thing I would like to express to you is , every week take the time to check and see if you have a bent shock ! This can totally mess up scaling the car if a bent shock is holding up your suspension or binding it .

Now that you have your car scaled lets try to understand a little more about how things work.

Before attempting any chassis adjustments it is important for you as a driver to know & understand what your car is doing on the track. The only way to understand how your car is reacting is through seat time. If there happens to be an experienced driver you can trust ask them if what you were feeling on the track reflects what they felt as well but keep in mind the more laps you turn, or practice you get; the better off you will be in deciding what your trouble points are on the track.

Learn how to hit the same line lap after lap before attempting any other adjustments. The biggest mistake rookie drivers make, are trying to adjust a chassis for what they believe is an ill handling car. You must become comfortable with your basic setups before you should even look into tinkering with any adjustments in the shop. Only when you can run clean consistent laps with the basic setup, should you move on to making major setup adjustments at the track or in the shop. 

 
 Only when you can run competitively with without spinning out, should you attempt to make any major adjustments in the shop or at the track . If you cannot drive consistent laps properly it is because you simply do not have enough seat time and or experience. At this point it is a good idea to ask a experienced driver what it is you my be doing wrong. And lets understand something that will save you your team and others money, “you aint the best driver to ever suit-up” ! I have found over the years to many drivers think “it's the car” when the fact is it's them. Learn to communicate with experience !!!

I can't stress enough the importance of adjusting only 1 component at a time. Making more than one change is nonproductive because you won't be able to determine what change made the car better or worse. Be sure to have plenty of paper and pencil on hand to take notes. It is critical to take notes after every adjustment you make. With all the adjustments available to make, it's real easy to forget what adjustment you made 3 practice sessions ago. Try to keep your scale sheet and notes together and if you are running more than one track make sure you mark on the notes and scale sheet what track it is for. Record keeping is important ! If you happen to go the wrong way with an adjustment you can always set it back to where it was before making the change by simply referring to your notes. Keeping notes also allows you to refer back to them to see how you progressed to cure your handling problem.

These notes could be useful for setups at tracks with similar configurations which can turn out to be a real time saver. Keeping track of adjustments, you will be able to refer back to your notes to see what worked & what didn't. This will help you decide what to adjust if a similar situation arises at another track. 

One of the more overlooked aspects of chassis setup is the driver himself. More so than ever it's critical for drivers to run the same line over and over when practicing & adjusting. If you're entering the track low in turn 1 and the car is loose, don't make an adjustment then start entering the same corner in the middle. This again is nonproductive and you won't know if it's your line into the corner that has helped or made your condition worse or if it's the adjustment itself. Driver consistency is very important when trying to determine how a car is reacting throughout a corner. Smooth & gradual throttle, brake, & steering inputs are required. Gone are the days of barreling into a corner, slamming on the brakes and cranking the wheel hard left.

As a driver it's very easy to mislead yourself into believing how your car is reacting through a corner. If your loose going into a corner then push in the middle and once again get loose exiting, it could very well be your driving habits. I see many drivers getting loose into the corners. When this situation occurs, the obvious reaction is to brake & turn into the spin in hopes of catching the back of the car. If you do manage to correct it, chances are you'll have a push in the middle as the car sets & grabs from you turning right in an effort to save it from corner entry. Now in an effort to get back low into the racing-groove, you jerk the wheel hard left applying throttle causing yourself to be loose . 

You may think your setup is all out-ta-lunch when the fact of the matter is that it's you causing two thirds of the problem all because your loose entering the turn. You may still have cornering problems in the middle and exiting, but because of your looseness going in, you the driver could be making the rest of the corner a problem when in fact it really isn't .

Because of this, it is important to divide each corner into 3 sections. The entry, middle, & exit. Each section of the turn will be effected by how you negotiated the previous section. Corner entry is where you begin your chassis adjustments. If you can't get into a corner, don't bother adjusting for the rest of the corner. Don't mislead yourself into believing the car is doing something that it isn't. In the above example you must take care of the loose condition entering the corner before you setup for the rest of the corner. Once your happy with the setup entering the corner, work on how the car feels in the middle. Only after you have a neutral handling car entering the corner & through the middle do you attempt to work on adjustments exiting the turn. Many times by simply curing your corner entry problems, you'll cure your middle or exiting problems. This is because you won't be making corrections to either loosen or tighten up the car based on corner entry problems. If you can always remember to divide each corner into sections and work on entry before worrying about the rest of the corner, it should go along way towards simplifying the whole setup process. DONT WORK BACKWARDS ! Be consistent & smooth with your driving inputs .

Adjusting your chassis

Camber is the inward or outward tilt of the wheel at the top of the tire . Negative camber is the tilt of the top of the tire towards the center of the vehicle . Positive camber is the tilt of the top of the tire away from the center of the vehicle . Camber adjustments are utilized to help maintain the maximum grip allowable from the surface of the tire through the corners of the track . Proper camber adjustments are very critical for achieving maximum cornering speeds ! Proper camber adjustments are achieved by reading tire temperatures . Remember one step at a time . You should be starting out at what your manufacturer recommended and if you ever get to the point you feel you need to change this use caution . It does not take a lot of adjustment in the front to get a totally ill handing car .

Lets take a look at how camber affects the chassis,

*More negative RF camber allows the car to turn into a corner quicker & will loosen up the chassis.

*Less negative RF camber takes away some of the pull to the left. The car won't turn in as quick into a corner & will tend to tighten the chassis.

*More negative LF camber will reduce the pull to the left while tightening the chassis from the middle out.

*More positive LF camber will increase the pull to the left & allow the car to turn into a corner quicker loosening the chassis.

*More positive camber in the RR will loosen the car from the middle out.

*More negative camber in the LR will loosen the chassis entering a corner.

Caster is the leaning forward or back of the tire at the top of the wheel. The upper ball joint is closer to the rear of the car. If you are running say a Northeast Modified like a Bicknell Chassis then you would be looking at the angle of the pin because they have a solid front axle. Positive caster is when the wheel is tilted back toward the rear of the vehicle and you would most likely find this on the right front. Negative caster is when the wheel is tilted forward toward the front of the vehicle and this would most likely be found in the left front.

Caster is used to provide directional steering stability. When setting your chassis you'll want to tip the top of the wheels back adding positive caster to provide you with that straight ahead directional stability. Some of you may have seen the clip that shows Danica Patrick spinning through the infield and when she gets semi strait she lets go of the wheel for a second and the steering finds center again, that is in part due to correct caster settings. There are NO circumstances where negative caster is preferred. Adjustment range is usually from +2.5 through +6.0 keeping in mind that 6 can be a very high number. Lets try to also keep this in mind, when your caster is set at lets just say 10 , when you turn your wheel to the right you are putting more psi at your right front contact patch because of the angle your spindle is. Lets take a flag pole with the flag at the halfway of the pole and lets assume this flag has a tractor trailer full of starch on it and you can spin it around the pole. Now if you put this flag in front of you with the pole on your left and the flag on the right, now take the top of the pole and lean it to your left a little. The flag is now pointing in a more upward position. Now holding that flag with your right hand if you were to bring it toward you it would be traveling downward. Now imagine that flag as your tire. So not only are you getting spring compression from the roll of the car you are also getting it from the ground up.

Proper caster adjustments will vary with each track and individual driver as well as the steering device you maybe using. The more positive caster the more feedback you will feel as a driver. More caster can also provide a more difficult steering effort, especially with a force feedback wheel. More positive caster will also give you a better feel for the car. More caster will allow you to make better decisions on the track about how the car is handling.

So why don't we crank the caster positive as far as it will go? Because too much positive caster also has it's drawbacks. When you turn a car left with positive caster the left front rises while the right front drops. This changes the weight on all four corners of the car. In effect you're taking cross weight out of the car the more you turn the wheel. The more positive the caster, the more cross weight there is being removed. The more cross weight you remove the looser the car will get.

In general, you'll want to run higher positive caster settings on a short track with tight corners, say like a very tight hairpin track it would be +4.5 to +5.5 on the right front. On a larger track with long and wide sweeping corners and long straight-away on the right front +2.5 or +3.5 would be preferred. Higher caster settings allow you to keep up with power slides on exit a little easier as well.

 
 Another element that must be considered is the caster split or caster stagger. Caster stagger is simply using different settings on the left front wheel than the right front wheel. When caster settings are different, your steering will tend to pull toward the side with the least amount of caster. On tracks where your only turning left, you would want a higher positive caster setting on the right front than the left front. This more positive caster on the right front will make the car pull to the left entering the turns, which is the preferred setup for entering the corners. The higher the caster stagger you run the easier the car will turn itself into the corner. Higher stagger will also take some feel out of the car and also force you to hold your wheel to the right down the straight .

Caster stagger will also affect braking. If you run too much stagger at tracks that require heavy braking such as hairpin track you may have to add brake bias. Although a better trade-off would be just to even up the caster allowing you to brake harder without causing the car to pull to the side with the least amount of caster.

Caster stagger is not the only adjustment that will give you that pull to the left. Many other factors must also be considered. Camber settings, weight balance, tire stagger, tire psi, and track banking also plays an important role. Many newcomers will be uncomfortable with the pull to the left and many may even think that there wheel won't calibrate properly. This pull to the left is normal and is the preferred setup to assist drivers when entering the corners with ease. Most caster stagger settings will be between 2 and 3 degrees. In other words, if you ran one degree positive on the left front, you would run positive 3 or 4 on the right front. In general, tracks that are small and have tight corners will require a higher caster split to help you turn into a turn better.

Caster

*More positive caster will loosen the chassis the more the wheel is turned through a corner.

*More positive caster will allow you to catch slides on exit a little easier.

*Caster adjustments are better felt through a force feedback wheel.

*The car will pull to the side with the lower amount of positive caster.

*The higher the caster stagger, the easier the car will turn into a corner.

*The higher the caster stagger, the easier the car will break loose braking into a corner.

*The higher the caster stagger, the less steering effort required. This will tend to give you a loose feeling upon corner entry. 

 
 Contact Patch When camber is set correctly it allows the entire surface of the tire to adhere to the track thus maximizing the use of the tire contact patch when taking a corner at high speed. On oval tracks you'll want to run with negative camber on the right front and positive camber on the left front. Using these camber settings will create part of the pull to left that will help the car get into and through the corner easier . The more excessive the cambers the greater the pull can be . Running excessive amounts of camber may cause the car to push upon entering due to the fact that the tires aren't running on the full contact patch of the racing tire . As a general rule, the flatter or slower the track the more camber you'll need on both front tires . More positive camber on the left front & more negative camber on the right front would be required at a flatter track verses a high bank track . Another factor in determining camber is body roll. The more the car rolls over through a corner the more negative camber you will need in the right front . Body roll is determined by how stiff your spring rates are and how your panhard or j-bar is set . The stiffer the springs, the less body roll. The less body roll, the less amount of negative camber required in the right front . Rear camber is not as critical as front camber due to the fact that the rear end is a solid axle . The same theory holds true though as you might want negative camber on the right rear and positive camber on the left rear on an oval track . On a flatter track you may not need any camber in the rear . Stagger in the tires (smaller left rear and larger right rear)will naturally create some negative camber in the right rear and positive in the left rear .When all is said and done, knowing how to read and understand tire temperatures will be the determining factor in how much camber to set in your wheels at . In fact it's the only way to properly adjust for correct amounts of camber . Since you must constantly monitor tire temperatures you will always be readjusting camber (at least in the front). Just when you think you have your tire temperatures and camber perfect, you'll change a spring or tire pressure to find more speed or the weather will be different forcing you to make some adjustments elsewhere . All that hard work you spent on achieving those perfect temperatures will have to be thrown out the window and the whole process begins once again . Now lets also keep in mind that adjusting one part of the car and not readjusting camber could be throwing off your original adjustment. Let's just say for example that you didn't take tire temperatures after changing the right front spring and running another 20 laps. Your times are slower after the spring change and you give up on that spring change because it made you slower. Maybe it wasn't the spring change that made you slower it was your camber being off that made you slower. Readjust the camber after running 20 laps with that spring change then decide if that was really the wrong way to go. Did you go faster after making the spring change ? No. Did you go faster after making the spring change and camber change ?  Take constant notes of each and every adjustment you make . If it doesn't work, you'll at least know how to set it back to where is was before you started .

Ok now lets try to get a better understanding out of what we have so far . Getting the front of your chassis set up is the most important part because ever thing after that follows, yes literally. When your racer goes into the entry of the turn as long as your front sticks your car wants to roll to the outside of the turn. It is simply put centrifugal force. The front tires when getting the proper grip that is known as centripetal force allow the car to turn left. Simply put it allows the tire patch (the part of the tire that is in contact with the racing surface) to over take the force of centrifugal. When this force is not working your racer gets what we call a push. So when the front tire (contact) patch can hold off the centrifugal force of the car wanting to go strait the car will want to turn left. Once you have achieved this you will start to deal with body roll. To better help with the  body roll lets go to Wikipedia and look up Roll Moment, "In a vehicle suspension, roll moment is the moment of inertia of the vehicle's sprung mass (the portion of its weight supported by the suspension). The roll moment is the product of the sprung mass and the square of the distance between the vehicle's roll center and its center of mass. If the vehicle is subjected to centrifugal forces, such as in a turn, the roll moment will cause the body to rotate (lean) towards the outside of the turn." 

Ackermann steering geometry is a geometric arrangement of linkages in the steering of a car designed to solve the problem of wheels on the inside and outside of a turn needing to trace out of the circles of different radius . Most short tracks have a corner radius of 150'+/-. For a race car that has a 108" wheel base and 60" width, the inside tire would need to turn 3.4 degrees and the outside tire would need to turn 3.3 degrees to have Ackerman Steering. In other words the inside tire needs to turn 1/10 th of a degree more than the outside tire in order to fulfill the Ackerman requirement for this car and corner. However, at racing speeds, tires develop what is known as slip angle. Despite the name slip angle it has nothing to do with slipping or sliding. Instead, it describes the flexing or twisting of the tire's contact patch. It's not unusual for racing tires to develop 6 +/- degrees of slip angle before they loose traction. Due to the magnitude of slip angle in the tires, that tenth of a degree steering difference mentioned earlier is negligible. So, when it comes to tuning your race car, take stock Ackerman off the list of concerns. However, slotted spindles that allow additional amount of Ackerman can make a big improvement in handling. Ackermann is a lot to get into for most racers so to keep it simple we will try to brake it down shall we say Barney style . Let's take your street car for example , if you go to a parking lot and turn your wheel all the way to the left and hold then allow the car to roll you will make a circle and you can keep going pretty much in the same spot over and over. Without Ackermann when attempting to repeat these circles your trail would look like that of a pig tail. If this simplified explanation does not work for you try this link at Wikipedia .