TC4 Gear Ratio... help!

[Tjay]

Hi,

I bought a used TC4 Team Kit. It comes with 104t-64pitch spur. The differential gear and shaft gear are all stock. The question is, how do I calculate the gear ratio?

Just so you guys know, the car is going to be set-up with 17.5 duo brushless motor with SPX speed control.

Thank you!

[heretic]

the internal ratio is 2.5; that is: (diff gear) divided by (small bevel gear)=2.5

your spur /pinion ratio is : (Spur-104 teeth) divided by (pinion, say 36 teeth)=2.88

then: 2.5X2.88= 7.22 ET VOILÀ !

for a 17.5 I would start with a FDR of 5.2ish for a medium sized track... so :

5.2 divided by 2.5= 2.08
104 divided by 2.08= 50, so you are looking for a pinion of 50 teeth... probably a bit more or less, of course, it depens on a lot of things.

Remember that a SPX requires a higher FDR ( smaller pinion) than regular escs when it is used in program "turbo" 7 or 8.

Ask at your track, and don't let anything become too hot.

have fun, the tc4 is a really good car.

[Tjay]

I saved this info on my cell phone. Thank you very much! This helps out a lot!

[redmike76]

gearchart.com

Originally Posted by Tjay

Hi,

I bought a used TC4 Team Kit. It comes with 104t-64pitch spur. The differential gear and shaft gear are all stock. The question is, how do I calculate the gear ratio?

Just so you guys know, the car is going to be set-up with 17.5 duo brushless motor with SPX speed control.

Thank you!