Gear reduction ?

[Kaz the Minotaur]

Is there a way to divide down all the gear reduction and figure out how big the pinion would be if it was just a pinion?


I'm really considering converting to brushless.

 

[lumax]

Take a look at this chart, you will have all the transmission ratio


Front and rear diff are 3:1 ratio


Center diff is also 3:1 ratio


For a stock TT single reduction will be 9.63:1


for example


10T and 96T


or


15T and 144T


I hope this help, I wish I could see a brushless rampage one day !

 

[pup1970]

Ok, The gear reduction using just the outside a,b,c,d gears at the 25,35,25,25 comes out to 1.4:1.

 

[lumax]

Right, I made the chart backward, I will change it now, I wrote 0.71:1 instead of 1.4:1... 1/X inverted


Rectification made on the chart rev.4

 

[Kaz the Minotaur]

Thanks. I have all the numbers I was just wondering how you did the math.


Thanks for the chart...I figured it out.

 

[pup1970]

Just to make sure I have this correct, with the dif ratios, 3/1 and 3/1 = 9/1. And if you take the gear side of 1.4/1 and multiply the 9/1 you will end up with a 12.6/1 using stock gearing? I know lumax said 9.6/1 but Ithought you multiplied the ratios with each gear reduction?

 

[lumax]

Here is the math (example for the stock TT);


number of tooth on gear...


A=29


B=31


C=25


D=25


First we must found the ratio between A and B...


B\A = Ratio 1


31\29 = 1.07


After, the ratio between C and D


D\C = Ratio 2


25\25 = 1


The ratio of the center diff


Crown\Pinion = Ratio 3


30\10 = 3


The ratio of the front and rear diff


Crown\Pinion = Ratio 4


33\11 = 3


The final ratio


Ratio 1 X Ratio 2 X Ratio 3 X Ratio 4 = Grand total ratio


1.07 X 1 X 3 X 3 = 9.63:1


Mean for every turn of the wheel, the engine make 9.63 turns


>>pup1970


you are correct, 12.6:1 is for the MT

 

[pup1970]

Thanx, I was not aware the tt and mt had different A/B gears.

 

[lumax]

Thanx, I was not aware the tt and mt had different A/B gears.

You know what, I found they were different only last week...

 

[Kaz the Minotaur]

Thanks...it took me a while but I figured it out.