When we first did our Slash 4×4 LCG shootout, we used stock power systems. Once the shootout was complete, and it was time to modify the trucks, I needed more power in my SSC Slash. I wanted something that was easily field programmable so that I could make adjustments on the go. I decided to give the Viper RC Copperhead Vx4R system a try. The VX4 signifies that it is a 4 pole motor, and the R signifies you are getting the Copperhead R ESC. Specifically, I went with the VX4R.45.  This is a 4500kv, 4 pole motor. In this series, Viper offers 3 KV options. the 3900 KV is a 540 4 pole, the 4500kv and 5100kv are both 550 4 pole motors.

The Copperhead R ESC is a sensorless ESC. It comes with 4mm  bullet connectors. It also comes with a Deans adapter on the battery wires. It has a remote switch, which is on a short 4″ lead. It comes preloaded with 5 profiles, ranging from a slower “beginner mode” to all out race spec. You can also individually program each parameter as needed.

I used the recommended gearing chart provided with the ESC to pick a pinion to start with. Being a 5mm shaft, and that the Slash uses a 32P spur, I went with a Robinson Racing 12T pinion with the 5mm bore.

To program this setup at track side, you can use a button on the ESC and follow the LEDs. But if you want to program more easily, Viper RC offers their Pro Gauge tuning card. Aside from giving you a way to program your ESC track side easily, it will also give you battery voltages, checks prop RPMs on a plane or heli, is a servo tester, and will test your input PPM signal, frequency, and receiver voltage. More on the Pro Gauge in a bit.

Installation in the Slash was straightforward. I screwed the motor to the mount, and used some double sided servo tape to hold the ESC in place on the chassis.

The most obvious thing I noticed the first time I drove the truck with the Viper system installed was the sound. The Viper VX4R.45 sounded like a circular saw. I thought something was wrong at first. I went online in search of others that have had this experience. It turns out it is absolutely normal. As it was told to me, the sound you hear when you stab the throttle is Torque!

There is no question the Viper combo is stout enough to keep up, and even pull away. I was under-geared at 12/54 just to be safe. I came off the track after the 8 minute main at 122 degrees. I had plenty of punch on the low end, and I was at the same speed as the other trucks at the end of the long back straight. Through a few visits to the track I played with gearing some more and am currently running 14/54. After 8 minute mains I am temping at around 140. A very comfortable temperature, I could even gear a little further. However it really isn’t needed. I have more power than I could control.

RC Soup went on a road trip to promote the Children’s Miracle Network benefit, hitting RCHR in Waterbury CT and RC Madness in Enfield CT. Both are indoor offroad tracks. RCHR is clay, while Madness is carpet.

RCHR was a little tight for all this power, so I had to dial back some of the settings on the ESC. Easily done with the Pro Gauge. Took me less than 5 minutes to dial back punch control, as well as forward power.

At RC Madness, which is a larger indoor carpet offroad track, I was able to put all the power back in.

At both tracks, my temps averaged in the 125 degree range on the motor after the Main. ESC was in the 90-95 degree range.

Value	At $149.99 retail (at the time of this writing), this is a super deal for a motor/ESC combo of this quality. It makes a ton of power, and was stone reliable. The Pro Gauge is available for $35 or so separately. I would say you should 100% opt for the Pro Gauge. It is money well spent.
Appearance	Not much to say about the appearance of the motor. It has some cool graphics on it, nothing too outlandish. I really like the color of the Copperhead R ESC. The footprint of the ESC is slightly larger than some of the other ESC’s I’ve used so be mindful of that in tight quarters.
Performance	Tons of power, plenty of torque. The system runs stone cold even when overgeared. With a 2S 5900 Mah Lipo, I was getting roughly 11 minutes of runtime. This is very good compared to other systems I’ve tested.
Durability	I beat the snot out of this motor. Never once had an overheating issue, never once had a reliability issue. Kevin also ran this ESC with the 5100kv 550 motor, and never once had an issue either.
Would I buy again?	I would absolutely buy this system again. It did everything I asked of it and never complained.

Overall I give the Viper RC VX4R combo a 4.5 out of 5 Spoons

I used this system for the majority of the summer season, as well as through the fall. It has performed well throughout, never once giving us an issue. It packs plenty of speed and torque for any 4wd SCT. Teamed with the Pro Gauge, this is a good all around system. This system is on average $75 cheaper than other popular unsensored 4 pole ESC/4 pole motor combos. Put the whole picture together, and you have a near unbeatable scenario.