symmetricon

iTrader: (27)

im rockin my new 1500series nue 1800kv 80 amp in my rc8e, i just switched it from the 2650. after some calculations i figured that with a 20 tooth pinion w/1800 should have close to the same speed as the 15/2650. what is your opinion, what pinion should i be running in my rc8e w/1800kv motor 4s?

GSMnow

The front and rear diffs appear to be 4.3 ratio. The stock spur in the RC8Be is a 46 from what I can see. At OC/RC the team setup used a 17 pinion but of course did not list the motor KV, so no help there. I will work it back using my tried and true 35 mph settings. With standard buggy tires (4.3 inch tall) it works out to a tire rpm of about 2700 or 11610 rpm at the center diff. With an 1800 KV motor on 4S, you have a motor speed of 26640. So you want a ratio close to 26640 / 11610 = 2.295:1 or 46:20

So I agree, the 20 tooth will put you right in the ball park, maybe a 19 on a tighter track like OC/RC or Hot Rod Hobbies. I usually end up geared more like 32 mph at these places, but you will not be hurting anything with a 20 on there.

Cain

iTrader: (294)

here is a calculator for you:

http://scriptasylum.com/rc_speed/_top_speed.html

works great for comparisons. When i ran the 2050kv neu wasn't odd for me to drop in the 20T pinion.

symmetricon

iTrader: (27)

thanx guys

Jason_R

I run a 20 the majority of the time with the same motor..seems to work really well and has very usable power.

b4maz

iTrader: (8)

I also went from a 2650 on 4s on my RC8e with a 14/50 to a 1800kv. I am gearing the 1800 at 19/46 to get the same speed. My motor temps are crazy hot though. 170.

nobike

iTrader: (147)

what run times are you guys getting with the rc8e with the mamba 1800KV motor and 4s 5000mah pack? and temps?