gear ratios

[Loopy1]

Does anyone know the formula for working out the correct gear ratios

[Catso]

Correct in what sense? Do you suspect you have some incorrect ratios?

[Loopymum]

It is for a racing car.

And we need to change from 2nd up.

[Loopy1]

Its for a race car.

We need to change from 2nd gear up.

[Catso]

In simple terms, the gear ratio is the diameter of one gear/wheel/pulley divided by the other.

[maxximus]

for a race car you will want include angine r.p.m. and wheel size.

[Loopy1]

We know that we need to know the tyre circumference and the diff ratio and the engine r.p.m.

But what is the formula for working out each gear??

e.g a over b x c =

[Catso]

Surely you also have to take into account the maximum road/track speed required, the range over which the engine produces maximum torque and how you wish to tailor the performance of the car?