Page 1 of 1

Gearing for a T3 -- Spur,Pinion,motor, Gear ratio info..

Posted: Thu Sep 25, 2008 5:23 am
by tecnica2001
Ok, I'm getting my T3 set up to run the Slot Machine that I was running in my XX.

Specs first:
I was running the slot machine on my Losi XX with the 2.19:1 tranny, 88 spur, 21 pinion with 2.2 buggy tires. so that would give me a 9.18 +/- gear ratio.

That gave me plenty of speed down the straight, good power coming out of the corners and the motor wouldn't get too hot.

What gearing would I need to come close to that type of performance on my T3??
What pinion size should I use??

I have an 87 spur, and the tranny is 2.40:1, it has bearings throughout, and 2.2 truck tires.

Thank you.... :D

Re: Gearing for a T3 -- Spur,Pinion,motor, Gear ratio info..

Posted: Sat Sep 27, 2008 5:53 am
by Stumpy
From memory, the recommended gear ratio for a T3 with 27T (24deg) stock motor is 10.44:1..

This equates to a 20 tooth pinion with the kit 87 spur..

cheers

Re: Gearing for a T3 -- Spur,Pinion,motor, Gear ratio info..

Posted: Sat Sep 27, 2008 8:05 am
by tecnica2001
Thank you sir 8)

Re: Gearing for a T3 -- Spur,Pinion,motor, Gear ratio info..

Posted: Sat Sep 27, 2008 12:55 pm
by aconsola
use this http://www.rcracing.com/Gear_Ratio_Program_1100.cfm To calculate what you need to run.
Put your transmission ratio, spur, pinion and tire size (actual overall tire diameter, not just the generic 2.2") in for your xx car. keep it set at "mid" and then click rollout.
Print the chart, then generate a second chart with the info for the truck. the pinion and spur you put into the program merely sets the middle values it used for generating the table, it will go 7 up and 7 down from there.

Then compare the results, find the rollout on the second chart that matches closest with the result you got from the first chart, and that is where you start.
It will likely be between 2 values, I would round down to the smaller pinion as the truck itself is a bit heavier, and the wheels take more energy to rotate.