run time question - RC-Monster Forums

**run time question -** 02.25.2009, 11:24 AM

currently im running a 2650kv cc motor in my rc8. my batterys are zippy 30c 5000mah 4s. i currently get a run time of about 13-15mins on the track going hard.

if i where to switch to a 2200kv motor would i get a better run time. right now the 2650 is retarted fast on the track. it kills all the nitro guys and all the losi 8ight-e cars with the losi brushless in them. so i would not mind going a little less power if i can get more run time.

thanks!

BrianG · 02.25.2009, 11:27 AM

Before going out and spending all kinds of money on a new motor, try gearing down a bit first. Would also help the "retarded fast" aspect as well.

shizzon · 02.25.2009, 11:38 AM

^^ what he said, it would be cheaper to play around with what you have then getting a whole other motor.

what is you current gearing and estimated top speed, as most tracks from what i have seen do not require anything more than 45 mph or less.

BrianG · 02.25.2009, 11:53 AM

Even with the current gearing, increasing punch control will help limit the current surges on take-off. Might mess with your timing when "blipping" the throttle for jumps or rough areas though.

02.25.2009, 01:10 PM

my punch control is set to 40% and im not blipping the throttle. i do very smooth movements. i never drove nitro for that long to start blipping the throttle lol.

also my gearing is set to 44/15 so right now its geared for 41mph. my motor temps are about 140 depending on how hard i drove. it i dont drive hard its about 125-130.

02.25.2009, 01:49 PM

im not saying im going to go out and buy a 2200kv cc motor today or anything. i just wanted to know for the future. the mains im going to be running right now (beginner) only run for 10mins and i can run a 10min main racing just fine. but soon im giong to have to bump up a level and the mains will be 20mins. and i know right now i cant run a 20min main on my motor and battery setup i have. i was just wondering if a 2200kv motor or a lower kv motor would help me do better then im doing now. i know i will not be able to run a 20min main no matter what. but trying to get as close to it as possible. (the track owner sometimes lets us brushless people start later or lowers the mins to 15. )

SpEEdyBL · 02.25.2009, 09:35 PM

The 2200 with the gearing you use now with the 2650, will yield about the same results as just gearing down the 2650. Basically, increasing the length of a motor (as is the case with the 2650 to the 2200), is almost the same as adjusting the optimal range of pinion gears.

jahno30 · 03.03.2009, 03:14 PM

Quote:

Originally Posted by SpEEdyBL

The 2200 with the gearing you use now with the 2650, will yield about the same results as just gearing down the 2650. Basically, increasing the length of a motor (as is the case with the 2650 to the 2200), is almost the same as adjusting the optimal range of pinion gears.

If this is the case, then what do us new B's need to be doing to get a set up to run for 20-30 mins without blowing something up...

hootie7159 · 03.03.2009, 03:53 PM

Lower kv motor on higher voltage...but even then making 20-25 min would be at the expense of the higher weight of a bigger lipo

BrianG · 03.03.2009, 04:25 PM

^ +1. Yep. Higeher voltage, lower kv (keep total rpm ~35k-40k), gear down, lighten the weight (tires are a good way to do this), higher capacity (mah) batteries, and be easy on the throttle (no super fast starts as that pulls a lot of current). Might help to set punch control higher on the ESC to tame those high current bursts, but might also mess with your throttle timing when you want a high burst (like before a jump).