Brushless technology and Lithium Polymer (Li-Po) batteries are getting a lot of attention these days. At first, everybody talks about the incredible speed, power and runtime that are achieved—three things that everybody wants from RC vehicles. But next, people talk about the volatile reputation of Li-Po batteries, and suddenly decide to stick with Nickel-Metal Hydride or nitro. The trick to getting the best experience with this incredible technology is having a source that has answers to the questions you’ll have. With the help of RC Monster, GorillaMaxx, RPM, AmpMax, Sky & Technology, and several others, we are going to take a look at brushless technology at its best using one of the most popular trucks in the industry, the Revo.
THE CONVERSION ... AND MORE
GorillaMaxx is following up its successful G2 E-Maxx race chassis with a similar design that converts the wildly popular Traxxas Revo to a battery-powered ballistic missile. The G2R conversion allows all the handling characteristics that helped make the Revo a force to be feared on the racetrack to remain intact. Nearly everything between the front and rear ends is tossed aside and replaced with GorillaMaxx gear, an E-Maxx tranny and a power system courtesy of RC Monster, Quark
and Ampmax.
FAST FACTS
Motor: Feigao 8L
ESC: Quark Monster Pro 125A
Batteries: Two Maxamps 8000mAh Li-Po
Speed: 48mph
Runtime: Approx 25 minutes
Heart Rate: Off the charts
The conversion is designed to fit right up to the Revo’s front and rear ends. It includes upper and lower chassis components made from carbon fiber, aluminum chassis braces that create a spine, front and rear skid plates and all the necessary hardware to hold it all in place.
Other items required include an E-Maxx tranny along with motors and speed control. A GorillaMaxx single speed conversion that eliminates first gear and uses only half of the tranny case was used as well.
For this project, I took the opportunity to upgrade the suspension arms to RPM’s dyeable units treated to red Rit dye and RPM Revo knuckles treated to orange.
While I had the red dye simmering, I tossed in the gray rockers just for fun…they came out as a very dark red. I also swapped the plastic steering components for an aluminum version from Golden Horizons.
I have been experimenting with the spray paints made for plastics and had a can of textured black on hand. I gave the RPM wheels a unique look with several coats of this paint.
Fortunately, after painting just one to test it, I liked it, so the other three followed. Team Losi Zombie Maxx tires (still one of the freakiest tread patterns yet) will provide the grip for just about any surface.
POWER SYSTEM
To determine the appropriate choice for a brushless system, I turned to Mike Cronin of RC-Monster.com. Mike is that “source” I mentioned in the opening paragraph. I explained the project to him and anxiously awaited his recommendation. What he hooked me up with was the Quark Monster Pro ESC from Sky & Technology, the sensorless, brushless Feigao 8L motor and a pair of 8000mAh battery packs from MaxAmps.
The Quark Monster Pro is a 125A speed control that can handle from five to 18 NiMH cells and two to six Li-Po. The unit’s built-in BEC (battery eliminator circuitry) has to be disabled when using more than 10 NiMH cells or more than four cells if using Li-Po. In this case, an external BEC is hardwired into the ESC’s battery connectors. I found some space behind the tranny to mount the Kool Flight Systems Ultimate BEC.
The BEC is then plugged into the receiver’s battery slot. I installed a second on/off switch in between the BEC and the receiver that powers up the radio separate from the ESC. The ESC requires programming and has several programming profiles that are set up using the transmitter’s trigger and a series of beeps that are emitted from the motor.
This can be a little tricky, so it’s necessary to pay close attention to the instructions. Reading them through a couple of times prior to plugging in the batteries was also helpful.
For now, I stayed with the basic setup, but advanced programs include drag brake, torque selection, motor and battery type. Default settings were appropriate for the motor and batteries I was using.
The two MaxAmps 8000mAh, 7.4v Li-Po battery packs are wired in series, providing over 25 minutes of runtime and more power than I have ever experienced with any other batteries. Li-Po batteries provide the scare factor to those unfamiliar with this technology. But again, as long as you read and follow instructions and precautions —and use only a charger that has Li-Po capability—you should have nothing to fear.
These 2s2p Li-Po packs can be pricey but worth every penny when you realize their potential. They’re an appropriate choice to go with the Feigao 8L motor supplied by RC-Monster.
The Quark Monster Pro ESC is secured to a Full Force RC Radio Tray that is mounted over the rear shocks. The unit to the rear of the ESC is a Team Associated cooling fan to help keep air flowing over the ESC’s aluminum case to avoid overheating.
The Li-Po packs are kept in place by Velcro straps. The aluminum angle you see here is not part of the GorillaMaxx kit but was added to help keep the batteries safely secured on the chassis.
The GorrillaMaxx chassis itself looks good enough to mount up in a shadow box frame and hang it on a wall. The totally cool carbon fiber with the reflective aluminum is a combination that never gets old. The kit goes together easily and weighs a mere 10 oz.
THE LAYOUT
Once the G2R is assembled, mounting the Revo front and rear ends is straightforward. And of course, mounting the tranny and motor is a no-brainer. You can mount the tranny with the motor to the front or to the rear if you are using a sensorless motor. This means you can swap any two of the three wires to reverse the motor’s direction if necessary.
With a sensor-based system, the motor’s direction cannot be reversed, so it’s critical to know which way the tranny needs to be mounted before bolting it up. I chose to stick with the dual steering servos for now, eliminating the one potential area on the chassis that could be used to mount a receiver.
This brings me to the only change I would like to see in the G2R. It makes no accommodations and includes no instructions for how and where the ESC and receiver should be mounted, so some creative thinking is necessary in order to keep it from looking hack. My solution involved a radio tray from Full Force RC mounted over the rear shocks and a single piece of carbon fiber mounted over the front shocks. These are simple items that could easily be included in the kit.
The new front plate served as a mount for my Spektrum receiver and the on/off switch for the external BEC (discussed later). The Quark ESC is mounted on the rear plate along with a Team Associated TC4 cooling fan. The
carbon fiber version of the G2R is set up with battery slots for side-by-side packs.
To provide a bit more security for the flat Li-Po packs, I used aluminum angle stock to add side brackets to the lower chassis tray. The aluminum version of the G2R has a lip running down the sides that would work without additional brackets. The CEN Matrix wing out back is mounted to Tekno’s non-adjustable Revo wing mount.
PERFORMANCE
This is it…this is the part we all look forward to. The Li-Po packs were charged, the Quark ESC was programmed and all systems were go.
I snapped a few quick photos while everything was still clean and shiny before plugging in the batteries and turning everything on. I was expecting quite a bit from the truck based on some of the threads I had read on various forums, but it turned out I was not prepared for the reality I was about to experience. A couple blips of the throttle were enough to raise my heart rate and hint at what was on tap.
I couldn’t resist (but should have) the urge to grab a fistful of throttle. The cool new shell was now on its head almost in the same exact footprint where the truck started. “Okay…roll on the throttle…got it.”
Go With the
Monster
When you decide to get serious about doing your own brushless project, you can avoid a lot of headaches by contacting Mike Cronin at RC-Monster.com. Not only does Mike sell just about everything you will need to build a ballistic brushless beast, but he also has the knowledge and experience to get you past the Li-Po fears, and help you understand the ins and outs of brushless/Li-Po technology. In addition to the power systems, RC-Monster can hook you up with the latest hop-ups for many of the most popular RC vehicles. And if you’re interested in putting together a brushless Revo similar the one here, the Monster sells a kit that includes the GorillaMaxx chassis kit as well as complete front and rear ends of a Revo and the parts to build an E-Maxx tranny. RC-Monster can truly be your one-stop shop for your brushless project. And rumor has it that Mike is working on some “must-have” hop-ups that you won’t want to miss, items such as an RC Monster-designed “slipperential.” Got your interest? Add www.rc-monster.com to your “Favorites” list to see what else Mike has up his sleeve.
This is what is left of your Revo once you remove everything that is not needed for the GorillaMaxx conversion. RPM arms, knuckles and bumpers were dyed using Rit fabric dye. The rockers were also thrown into the red dye but turned out a deep red color since they started off as gray.
Chrome RPM wheels were painted with a textured black paint that is formulated specifically for plastics. Its durability will be determined soon, but for now the wheels have a rather unique look that’s nothing like all the other wheels out there. The Losi Zombie Maxx tires I used are a bit soft and had a tendency to balloon severely at times. Some reinforced strapping tape on the inside of the tire will help prevent this.
GorillaMaxx offers an optional single speed conversion for the E-Maxx tranny that eliminates first gear. It also eliminates half of the stock tranny case and replaces it with an aluminum cover. The only modification required to the internal elements of the tranny is to cut off the top gear that is no longer needed. The stock motor plate was modified to remove the unused second motor mount location and treated to a Greased Lightning bath to remove the blue anodizing.
I have had tires come unglued before, but I have never had the foam blown completely out as seen here. The soft tires ballooned like saucers and eventually broke the inside seal loose, setting the foam free. This put a temporary end to the day’s fun. As mentioned earlier, some strapping tape secured to the inside of the tire will help to eliminate the ballooning issue.
A carbon fiber tray was mounted above the front shocks to serve as a radio tray for the Spektrum receiver and power switch. The stock 2055 Traxxas servos were used for steering.
A Golden Horizon Revo steering unit replaced the stock plastic version. The steering linkages are shown in the stock position in this image. But because the G2R’s servo mounting plate is not angled like the Revo chassis, it was necessary to mount the linkages on the top side of the steering unit. (This image shows the setup from the bottom.)
MaxAmps 8000mAh Li-Po packs fit in the same space as standard
batteries, but
provide an increase in power and runtime. Li-Po packs may come with warnings about the potential danger of charging and using them, but in reality, using them correctly is not that difficult. It does involve doing something that so many of us avoid on occasion…reading instructions and caution notes. These two-cell packs include an external plug for balancing the cells. I used the LBA6 from Hyperion RC Products. When hooked up to the battery, this unit will detect all cells with a higher voltage and automatically discharge them to match the other cells.
Take two! This time, the Zombies lit up, throwing dirt and small stones about 10 feet to the rear as the E-Revo accelerated to roughly 48 mph according to my radar gun before running out of room.
At this point, I had not been able to get a full squeeze on the trigger. I needed a few more minutes to get used to the newfound power and speed. At roughly 35mph, the truck would pull the front wheels off the ground and even flip if I wasn’t easy on the throttle. I could see I was going have to learn to drive all over again.
After changing my driving style, I was able to keep the wheels on the ground and maneuver the truck around the empty dirt lot. The handling was similar to a stock nitro Revo, but the instant torque provided by the brushless system made a significant difference in how it needed to be controlled. I am guessing that, in the right hands (not mine yet), this thing will keep up with the truggies at the local track. Maybe my nitro trucks do have reason to be nervous. I already want to build another brushless vehicle. Maybe a 1/8-scale buggy.
CONCLUSION
This reborn Revo is the type of project that has my nitro vehicles nervous.
But there is much more to learn and understand about this incredible technology, so they won’t be neglected…yet. The Revo’s innovative suspension design has done well on the track since its introduction. The E-Maxx G2 chassis from GorillaMaxx has also done well. Seeing the two come together seemed only natural. The final truck doesn’t appear to be a converted vehicle but looks like a production kit…and performs as one, too.
The level of quality in GorillaMaxx products coupled with the level of professionalism and customer service provided by RC Monster helps take the sting out of treading in unfamiliar territory. So if you’ve avoided the brushless/Li-Po scene for one reason or another, maybe it’s time to take a deep breath and jump right in. But remember, once you go brushless, you may never go back.
The Feigao 8L brushless motor will fit where a standard 540 motor will fit and has a can that is just slightly longer. The RC-monster heatsink bolts directly to the motor and has the difficult task of keeping the motor from getting too hot.
Paul Rush of Hijacker RC Designs did such a great job on the Project ArenaMaxx that he is back for an encore. This time, he has done up a low slung, brand new Revo body from Xtreme RC Racing Products. If you would like Paul to throw some paint for your next ride, you can contact him at hijackerrcdesigns@hotmail.com—
reasonable rates and raceable paint.
MaxAmps 8000mAh Li-Po packs fit in the same space as standard 
