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BrianG · 01:55 PM

I ran it for a while today. As expected, the back end is a little squirrely. Did some high speed runs and without a GPS or radar gun, it's hard to tell the exact top speed, but it's close if not over the calculated value. The 3s lipo retained over 3.7v/cell for around 3-4 minutes, so that helped. To get the thing under control, I did some burnouts/donuts/drifting to heat the tires up. Worked too; got them up to 127*F. After that, traction was a TON better and had much better control. The road in front of my house has a crown (uneven at that), not to mention a manhole cover, so getting it to steer perfectly straight was impossible. Still pretty fun though.

Temps were good: barely over ambient (65*F) for the batteries, 108*F for the motor, and 113*F for the ESC. Not bad for extended speed runs. Those clip-on motor heatsinks had partially came off and had a ton of sand/grit between them and the motor; so they were actually insulating the motor rather than cooling it. I bet the temps would be better if they were actually mounted right. I'm gonna tack them on with some thermal adhesive to keep them in place, yet not so much that I can't take them off if I want.

The 3s 3300mAh 30C elite batteries help up great. Like I said, they held higher voltage for quite a while. I'm not running the LVC since I use 6 NiMH cells or 3s lipo depending on if I'm in the house or outside. When I noticed a drop in power/speed, I stopped. Two minutes after stopping, the voltage was 3.32v/cell. A little lower than I like to run, but I'm sure they would drift back up more to a more acceptable ~3.5v/cell after 15-20 minutes unloaded.

Runtime was a hair under 25 minutes, which puts average current draw at ~8A. Given this is 2WD, low vehicle weight, and limited traction, I can't see this setup drawing more than 50A bursts.

Putting them on the charger, they only took in ~400mAh before they reached 3.8v/cell. The voltage was pretty steady after than until the last 600mAh as they rose to CC/CV threshold. Seems these are decent cells. Probably not good for 1/8 scale, but perfect for 1/10 2WD applications.

	(#67)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	04.15.2009, 01:51 PM I ran it for a while today. As expected, the back end is a little squirrely. Did some high speed runs and without a GPS or radar gun, it's hard to tell the exact top speed, but it's close if not over the calculated value. The 3s lipo retained over 3.7v/cell for around 3-4 minutes, so that helped. To get the thing under control, I did some burnouts/donuts/drifting to heat the tires up. Worked too; got them up to 127F. After that, traction was a TON better and had much better control. The road in front of my house has a crown (uneven at that), not to mention a manhole cover, so getting it to steer perfectly straight was impossible. Still pretty fun though. Temps were good: barely over ambient (65F) for the batteries, 108F for the motor, and 113F for the ESC. Not bad for extended speed runs. Those clip-on motor heatsinks had partially came off and had a ton of sand/grit between them and the motor; so they were actually insulating the motor rather than cooling it. I bet the temps would be better if they were actually mounted right. I'm gonna tack them on with some thermal adhesive to keep them in place, yet not so much that I can't take them off if I want. The 3s 3300mAh 30C elite batteries help up great. Like I said, they held higher voltage for quite a while. I'm not running the LVC since I use 6 NiMH cells or 3s lipo depending on if I'm in the house or outside. When I noticed a drop in power/speed, I stopped. Two minutes after stopping, the voltage was 3.32v/cell. A little lower than I like to run, but I'm sure they would drift back up more to a more acceptable ~3.5v/cell after 15-20 minutes unloaded. Runtime was a hair under 25 minutes, which puts average current draw at ~8A. Given this is 2WD, low vehicle weight, and limited traction, I can't see this setup drawing more than 50A bursts. Putting them on the charger, they only took in ~400mAh before they reached 3.8v/cell. The voltage was pretty steady after than until the last 600mAh as they rose to CC/CV threshold. Seems these are decent cells. Probably not good for 1/8 scale, but perfect for 1/10 2WD applications. Last edited by BrianG; 04.15.2009 at 01:55 PM.