At some point in your team’s life, you might venture out to different tracks than the one you race on regularly. When you do that, you must learn how to setup for those tracks. If they are much the same as the one you raced on, not much will change. But, if they are very different, you might have a difficult time dialing the car in.
There is seldom much time to make adjustments to your setup before qualifying at the new track, so here are some helpful hints on what to expect and some tips on doing some prep before you go so that you will be better prepared.
Types of Race Tracks – There are different types of race tracks and I wanted to define those before we get into the meat of the subject so we’ll know which direction we want to go with changes. I’ve had to work with teams that ran traveling series a number of times and I’ve had my behind handed to me more than once when I couldn’t get adjusted to a different type of track in time to go racing. So, here is some of what I have learned and been taught.
There is the flat track configuration verses the high banked track, and there are varying degrees of banking in between. Then there are longer verses shorter tracks. The longer ones have more overall speed as well as higher speeds through the turns. It goes without saying that you’ll need to re-gear the car for the longer and faster tracks.
The transitions from straights to the banking can be much different between race tracks with similar banking angles. For some tracks, the inside stays relatively level and the outside rises up to form the banking. For others it is the opposite, the top remains more level and the bottom drops down to make the banking. And for many, it is a combination of each of the above.
This difference in shape and size makes a big difference in how you setup your car in terms of springs and shocks. Finding the basic balance for mid-turn handling is the same process for each of the track configurations, but the stiffness of the springs and shock values need to be tailored to each track.
Going From Flat To Banked – Banked tracks have more G-force, more mechanical downforce and have generally better bite off the corners than do flat tracks. First, with more G-force, the balance must change. You were probably more concerned with bite off the corners on your flat home track, but that won’t be as much an issue with the banked track.
With a higher lateral G-force caused by the higher corner speeds, the overall chassis roll will increase, but the rear will increase more than the front. So, we must control that added roll by doing one, or a combination, of the following.
We can increase the rear spring split, i.e. softer LR spring and/or stiffer RR spring. We can also raise the panhard bar to decrease the rear roll by increasing the rear stiffness. We also need to stiffen and/or rearrange the front spring rates.
If you ran a softer RF spring than the LF spring, you will need to reverse that. Tracks that rise up on entry are hard on the RF spring. You’ll need to stiffen that, even if you run bumps.
If you ran a higher range of cross weight, you need to drop down to the lower range. For example, if your front to rear percent of total weight were 50%, and you run 58% of cross weight at your flatter track, you probably need to drop down to 51.7% or so for the high banked track. The higher, equal to the left side percent, cross weight never worked well for me on high banked tracks.
Going From Banked To Flat – What you read above is pretty much in reverse of this scenario. You are probably used to flat footing it off the corners at your high banked home track because you always had that high amount of mechanical downforce loading your tires. They gripped well because of the extra loading. Now you’ll need to make changes not only to your setup, but in how you drive the track.
If you do the reverse of the above for setup, you will also need to develop bite off the corners. Whereas we did not want much if any rear steer on the high banking, we’ll need to create some steer to the left on acceleration off the corners to offset the tire slip that will come.
We have outlined various techniques for doing this over the past few months and years, so here is a recap. If you allow your car to squat, a higher left trailing arm angle will cause the LR wheel to move back during squat and cause rear steer to the left which will counter the tire slip.
If you like anti-squat, you can move the third link to the left to put more of the displaced loading caused by the third link angle to be placed more to the left side of the rear end. This loads the LR tire more than before, which creates more bite off the corner.
The most important thing is the way the driver applies throttle. On the high banks, you could probably go to full throttle in one quick motion. On flatter tracks, you’ll need to slow that motion down quite a bit. It is called squeezing the throttle and you need to educate your foot.
Inside Drop To Outside Rise – If you are going to a new track where the outside rises up to form the banking, the RF shock compression and spring rate must be increased to control the upward motion of that corner of the chassis. A typical example is Daytona, not that you’ll be running your late model there any time soon, in that the track rises up to form the 31 degree banking. It hammers the RF corner of any car running there.
The same track that rises up on entry also lays down on exit. The outside must come down to form the lower straight away banking, so the RF falls off a cliff so to speak. When this happens, both the RF and the LR shocks must rebound quickly in order for the tire to maintain contact with the track surface.
So, you’ll need to run less rebound in the RF and LR shocks. I have witnessed this happening at some tracks. If you ran a stiff rebound LR shock to free up a car on entry to your track, at this type of track you’ll need to go back to a more conventional rebound rate.
Outside Rise To Inside Drop – When you run a track where to get the banking, the inside drops, the left front shock rebound rate must be less than “normal” to allow that wheel to rebound and stay in contact with the track surface on entry.
Also, the RR shock must also have less rebound rate to allow it to droop as the left front of the car follows the dip in the track. If not, the car could get tight from load being lifted off the LF and RR tires during this transitional phase. Less loading for that diagonal verses RF to LR means a higher cross weight momentarily.
What goes down must come up so to speak. That dip on entry becomes a rise on exit off the corners. Now the LF will be forced upwards quickly and we need to think about that motion. If we try to control that, more load will be applied to the LF and RR corners and that would reduce the cross weight loading causing a loose off condition.
Rather than controlling that rise at the LF, maybe we should allow it to happen, as long as it doesn’t cause our ride or bump springs to go into coil bind. A little less compression setting in our LF shock might be welcome in allowing that corner to transition into the rise in the track on exit.
Going From High Banked To Super High Banking – For super high banking, there is a greater amount of mechanical downforce, and this makes the car travel more, well, down. If you run conventional springs, then you must stiffen them quite a bit.
When we used to run Bristol, which was 26 degrees in banking in the late ‘90’s and early 2000’s (not the advertised 36 degrees), our Goodies Dash cars and the New England Tour Modifieds had to more than double their spring rates to keep from bottoming out.
For example, the banking at Slinger is somewhere around 16 degrees from the reports I have gotten back from competitors who physically measured it, and those cars must increase their conventional setup front springs by about 1.5 times the normal 12 degree track rates.
If you are running bump rubbers, or bump springs which are now becoming much more popular, you must increase the spring rate of your bumps. The normal bump spring rate of 1200 to 1500 ppi must now be upwards of 1800 to 2200 ppi rates, or they will coil bind.
Circle Track To Road Racing – I threw this in because some teams want to learn the road racing side of stock car racing. In Cup racing, they now run Sonoma Raceway and Watkins Glen International road racing courses. So, if your desire is to someday run in Cup either as a driver or crew chief, you’ll need to know a few things about road racing setups.
First off, in case you didn’t know it, you’ll be turning left and right. What works for the left turn must also work as well for the right hand turns. So, the three areas that need to be equal are: 1) front geometry, 2) spring rates right verses left, and 3) weight distribution. Let’s take number one first. The front geometry includes several settings. First off, the Moment Center must be centered and move equally to the side for each direction of turn. And, it must be designed to not move very far from centerline.
Next, continuing with the front geometry, the front cambers must both be negative. This hurts the inside tire going through each of the turns. And, the Ackermann must be equal for each direction you are turning. So, if you adjusted the steering arm lengths to set your Ackermann and ended up with different length arms, that is a no-no for road racing. You’ll have to move the steering rack fore or aft to set your Ackermann and keep equal length steering arms.
Also, you cannot use caster split on a road course. The caster must be the same on both sides and most road racers use more caster than you would normally use. And along with that, the degree of spindle inclination must be equal for each of the spindles, whereas we usually use different degrees for left verses right spindles.
For number two, the spring rates must be equal for the front springs, and the rear springs side to side, not front to rear. Most road racing late models use high rear spring rates about twice the normal conventional spring rates. Even then, the roll is too much, so a rear sway bar is needed.
Finally, for number three, the overall weight distribution must change when running a road course. The left side percent can no longer be 56 or 58 percent. You’ll need to work towards equal left and right side percent rates.
And, the cross weight must be 50% for a road racing car. That way, it is the same for right and left hand turns. So, if the front to rear percent dictates the correct cross weight we need to run for circle tracks, then we must develop a front to rear percent number in our road racing car that will want 50% cross weight.
Conclusion – We have tried to get you thinking about what changes will be needed when you travel to a different race track for the first time. You might be able to think of other things that must change, but with these suggestions, you’ll begin to understand the dynamic differences between tracks of different configurations and sizes.
If you can get good at this, you will have much more fun with your travels and your team will be much more successful. Try to be prepared by having a variety of springs available in the range that works for the new track and use adjustable shocks so you can fine tune that balanced setup for the transitions. Most of all, have fun with your travels. It’s the journey that counts, not necessarily the destination.
Sources:
Afco Racing
www.afcoracing.com
800-632-2320
Allstar Performance
www.allstarperformance.com
269-463-8000
Capital Motorsports Warehouse
www.cmwraceparts.com
800-278-2692
Coleman Racing
www.colemanracng.com
800-221-1851
Day Motorsports
www.daymotorsports.com
800-543-6238
DRP Performance Products
www.drpperformance.com
888-399-6074
Integra Shocks and Springs
www.integrashocksandsprings.com
800-472-3464
PitStopUSA
www.pitstopusa.com
866-722-3432
Smileys Racing Products
www.smileysracing.com
866-959-7223
Speedway Motors
www.speedwaymotors.com/
855-313-9175
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