Setup sheet
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| Final drive ratio | 10.21:1 |
| Pinion | 20T |
| Spur | 84T |
| Internal gear ratio | 2.43:1 |
| Differential fluid | 3,000 cSt |
| Shock oil front | 30 wt |
| Shock oil rear | 35 wt |
| Wheel hex | 12mm |
Published by the manufacturer. Everything else on this sheet has to be measured on your car — no spring rate, ride height, droop, camber or stagger figure is published for it.
A sheet is only worth something if the track is on it as well as the car. A setup is not a property of a car; it is a relationship between a car and a surface on a particular evening.
Symptom finder
The same list as Chapter 17, in the order the book puts it. Find what the car is doing, then work down.
Before any of it: is the problem everywhere on the track, or only in one place? A problem at one corner is usually the track or the line, not the car.
Gearing
Final drive is spur divided by pinion, multiplied by the internal ratio.
One tooth on the pinion moves the final drive by about five per cent. Change the pinion, not the spur, when you are chasing a track — it is the cheaper part and the quicker job.
Stagger
Measure the tape around the middle of each rear tyre, on the car, with no load on it.
Stagger is a circumference difference, not a diameter difference. Measuring the diameter and calling it stagger gives you a number about three times too small.
Roll centre
Chapter 10 shows how the construction is done on paper. This does it with your car’s own measurements, and redraws it every time you change one.
Heights are from the ground up, lengths are measured flat. The roll centre moves as the suspension moves: this is where it is at the ride height you measured, which is the one that matters because it is where the car sits.
Night log
One entry per meeting. In a season this is the thing nobody can sell you: a record of what your car does on your track.