In the blog post below, we explain what stagger is and tips on determining if you have too much or not enough.
What is stagger?
"Stagger" refers to the variance in tyre circumference between the left and right rear tyres. This difference in tyre circumference creates stagger.
Using stagger is to assist the car in negotiating turns on oval tracks. Oval tracks typically have left-hand turns, and the stagger helps the car make these turns more effectively. With larger tyres on the right side, the car tends to steer left naturally. As the car enters a left turn, the larger right rear tyre covers more ground per revolution than the smaller left rear tyre. This difference in tyre size creates a natural turning effect, helping the car navigate the turn more smoothly and efficiently.
A basic rule of thumb
The tighter the radius of a corner, the larger the diameter of the outside tyre must be in relationship to the inside. So, the tighter the race track, the more stagger required.
Track conditions also dictate the amount of stagger used. If you need help turning the race car, stagger can help. It will make the right rear overdrive the left rear and drive the car in a tighter arc, making the car turn itself. A heavy or tacky track will require more stagger. A dry, slick track will require less stagger.
Stagger also changes the corner weights of the car. When a larger right rear tyre is used, it adds weight to that corner and puts more tilt into the chassis. When a larger left rear tyre is used, the corner height at that corner is raised, and more weight is added to that corner. It also takes out the chassis tilt, takes the weight off the right rear, and adds it to the left rear, tightening the chassis at the corner exit. If you want to keep your chassis heights the same when going to a bigger tyre, take turns out of the torsion stop to maintain the same height.
Do I have too much or not enough stagger?
Stagger puts negative camber into the rear tyres. This will put more weight on the inside edge of the left rear and right rear tyres. Reading the tyre wear pattern is one way to tell if the car has too much stagger. If there is a lot of heat on the inside edge of the right rear as compared to the rest of the tyre, then there is too much stagger. Stagger is effective under acceleration when one wheel is driving around the other. More stagger will make the right rear drive around the left rear. Less stagger makes the left rear more dominant.
There can be such a thing as having too much stagger. There are too many stagger scrubs off-speed down the straights. The more stagger, the more tyre scrub on the straights. The longer the straightaways, the more this tyre scrub slows down the speed. The key to ultimate laps is keeping the car as straight as possible and having as little drag on the car as possible. So, on faster, longer tracks, the amount of stagger used might be a compromise between handing in the turns and having less drag down the fast straightaways.
However, this "compromise" might not be such a deficit to the driver. Once the driver has passed the apex of the turn (centre point) and is on the throttle to exit the turn, the front wheels should be neutral (straight ahead) to slightly left to steer off the corner. This means the chassis will have a slight push coming off the turn with stagger turning the car. Once a driver gets used to this, he will be much faster. This is especially true on a bigger race track or a faster race track, where just a slight amount of grip loss will cost several thousandths of a second while the competition drives by. A driver often uses too much stagger to get rid of this slight push getting off the turns. He is expecting the car's rear to steer instead of doing some of the steering with the front wheels.
Take some stagger out when the track gets dry and slick, but don't take out so much that the car gets loose. What this means is that a lot of times, a driver will think his car is loose when it is actually tight. When they enter a corner, and the car won't turn, they do things to make it turn - tossing it in sideways, getting on the gas harder and quicker. This will get the tyres spinning and get the car loose from the middle of the corner and through the corner exit. Then they think the car is loose because it was loose coming out. In reality, they made it loose because it was too tight. It would help if you had enough stagger so the car would turn when the driver got back on the throttle.
Tips on Measuring
No need to pull out the calculator. Measure the bigger tyre first around the centre in this case the tyre is 102 1/4”, then go the the smaller tyre measure it. Where the tape measure meets at 102 1/4” at the same spot as the larger tyre will then tell you the size difference between the two tyres. In this case approx. 8.5” that is your stagger difference.
It's crucial to approach stagger adjustments in conjunction with other suspension components and consider the overall setup of the car. Most chassis suppliers have recommended stagger setups use these as starting points.
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