11-04-2014, 09:50 AM
Join Date: Nov 2001
Location: Burbank, CA.
Originally Posted by M7H
A 2650kv motor on 4s, is just as fast as a 2000kv motor on 6s, so if you are looking for a set which you can use on 4s but also on 6s, go for a 2000kv motor max!, and gear up that pinion on 4s, until you reach the speed you want!
i did test my 966e with 4S lipo => https://www.youtube.com/watch?v=uwOzil59Mvg
check the description for set-up details.
To give you an answer on what pinion you should start with.
Lets take a 1800kv speed passion blaze motor.
If you want to gear the car to reach 85kmh, this is how you need to gear it.
1800kv x 3.7V x 4S = 26.640 rpm (theoretically)
check gearchart.com an fill in the figures you know and to find out the gearing you need to accomplish this.
- internal ratio = 1.714 (28/18)
- rpm = 26.640
- tire diameter = 73mm
And start playing with the spur (48 / 49 / 50) and pinion (14 => 21), until you have the desired speed, then check what roll-out goes with this speed.
If you fill in everything correctly, you will come to a roll-out of around 53,5mm and a spur / pinion of 50 / 20.
The "roll-out" chart you can also download from serpents website on the 977e page.
If I'm correct, a 21 pinion is the max pinion that fits the car.
thanks i for the info this helps a lot.. Im going 4s for sure it will just right for our track