The ET value is the Off-set value, that is, the offset, the degree of deviation between the junction surface of the wheel hub and the center line of the rim, the unit is MM, and there are three types: positive, zero, and negative.
When the Offset value is 0, the contact surface between the wheel and the hub is at the center line of the wheel. When the Offset is a positive value, the more the contact surface is inward.
Changing the Offset of the rim will change the track of the car, and the track refers to the distance between the center line of the tire, so if you simply increase the rim and tire without changing the Off-set, it will not affect the track.
The effect of changing Off-set: If you switch to a rim with a smaller off-set value, the wheelbase will be widened, which can reduce the shift of the body’s center of gravity during cornering and increase the car’s cornering speed limit. However, the relative increase in the distance between the center of the steering shaft and the center of the tire makes steering difficult and increases the load on the steering mechanism, which increases the deformation of the steering gear. Therefore, it is necessary to appropriately increase the Toe-in to correct it. However, this is an abnormal method, so the Off-set of the front wheel should be as close as possible to the original Off-set value. For the rear wheel, when switching to a larger rim, if you do not change the Off-set, you will often encounter the problem of the suspension mechanism being touched on the inner side of the tire. Therefore, if the wheel arch is not worn, use the positive Off-set. A rim with a smaller set value is good. But it should be noted that for cars with independent suspension of the rear wheels, such a change will increase the amount of change in the Toe of the rear wheels when accelerating and braking. This has no effect on ordinary street cars, but for racing cars. It’s a big problem.
Post time: 25-11-21