Rim/tire size effect

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1

Can someone explain rim/tire size effect on handling in FM7?

Thanks,

Backwoods Racing

2

i’ve not really noticed any effect, i usually use it to drop some PI when necessary by increasing rim size.

3

Specifically, is the tire sidewall flex modeled in FM7? Is there a reason not to increase rim size to max and tire sidewall to minimum if allowed?

4

The car becomes sharper with bigger wheels. You can use this in combination with lighter wheels to preserve PI while making the handling sharper.

Wheels can also be used to increase weight and lower PI just enough for you to squeeze in something else.

Unsprung weight is not simulated. In Forza, weight is weight, no matter where it comes from.

3 Likes
5

Well said. But I’m making it bit more definitive.

Low profile tire. Sharper and more precise handling , but on the limit of the grip it can be snappy. In other words once you lost, the grip specially if it is oversteer your car is sideways very swiftly, and the correction must be extremely quick and regaining the grip is just as snappy. (Especially on sim steering)
High profile tire. Loose handling, feels that you have slightly less grip overall. How ever when the grip is lost, specially if it’s oversteer the slide is more gradual, it doesn’t snap away from you as easily, and the grip return is also more gradual making the car easier to control in oversteer situation.

How ever most use rim size and rim selection to just matching the PI to desired class

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6

Only do it if you have race tires , they’re a soft compound and fold od easy with understeer. Bump the rims up in the front amd it controls it more.

7

Delete wrong post.

8

In the real world Road and Track had a great article on wheel size and handling.

They concluded that 18" wheels were the best compromise, and the reason why that turned out that way was strange. In effect the 19" wheels gave so much more grip that they adversely affected the grip of the wheels on the inside of the turn. Basically you want grip to be spread across all four contact patches as much as possible. Even if the peak grip of the outside tires was higher, you still want the inside wheels to be managing some of the load.,

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