MRA Non-Dimensional TTC Data

[Dave K]

Inside the m-code provided with the MRA non-dimensionalized tire data in the TTC, why is the road surface coefficient set to .6? (this was the default in our copy, at least). Is it a standard or average or something?

[Dave K]

Inside the m-code provided with the MRA non-dimensionalized tire data in the TTC, why is the road surface coefficient set to .6? (this was the default in our copy, at least). Is it a standard or average or something?

[Mike Macie]

At Calspan, the surface used for tire testing is similar to sandpaper. Formula SAE tires tend to see a autocross course/parking lot asphalt surface which has less grip. The 0.6 coefficient adjusts the model to predict tire performance on an asphalt type surface. The value of 0.6 resulted from MRA's experience and feedback received from teams with the data.

[ben]

As a design judge it's difficult to judge teams whjo talk about the TTC data without having seen it myself.

Now I know there's a grip level fudge factor in the MRA fitting, that's the sort of parameter I would expect a good team to have validated against track test data before using the data in a simulation.

Ben