testing and shakedown question

[CyrM]

Hi there

Got a question for you all. (a hypothetical scenario)

A team just rolled out a prototype and are going through their first shakedown test. How do the engineers / mechanics determine the VERY baseline setup for the first hotlap?

Usually, when trying to figure out the handling balance of the car, does one adjust alignment, rollbars down to the shocks (one adjustment at a time of course), or the proceed the other way.

If anyone can share some insight, that'd be much appreciated.

Thanks

[David Ferguson]

Experienced people nearly always start with what they know. Even if a new car has different geometry, they will often start with the same roll-stiffness distribution that worked with their last effort. They might even start with similar springs/shocks.

But after the first few "let's see what falls off the car" sessions, it's usually time to map out what the car likes/wants -- you'll try to find the balance first, then go both down and up in spring rates to evaluate the response to the changes. They may try running the car at different rakes, (which will involve finding the balance once again). They will be constantly taking tire pressures and temperatures to be sure the static camber is right.

So, this boils down to "they guess", but with experience they can make a more "educated guess".