FDR - How to work out

[zackmitchell]

Hi Guys,

Trying to work out final drive ratio's for an MI3.5 and thought it was a combination of motor pinion and spur gear divided, but when looking at the provided set up sheets and using this formula its a very different answer to what the set up sheets are saying the FDR is.

Can anyone shed some light on my blonde moment?

Thanks in advance

Zack

[coolcars782]

Spur gear / Pinnion Gear * Internel Ratio (Gearbox/Transmission Ratio) = Final Drive Ratio

e.g.

For a b4 which i only know

81/19*2.6= 11.08


Schumacher Mi3.5 PRO transmission/gearbox ratio is 1.8

so will be

Spur/Pinnion*1.8 = FDR

[zackmitchell]

Cheers for the quick reply,

That seams to make the FDR come out right from the set up sheets.

Zack

[jono83]

You also need to consider rollout( wheel and tyre diameter)

[discostu]

roll out isn't so important on a tc running rubber tyres foam tyre racing is a little different as tyre diamters change so the roll out will change.

stu rand

[zackmitchell]

Where does the rollout come into it?

Will be running schumacher yellow minipins indoor on carpet.