Chingon
Quarry Creeper
After the 2025 NM State Championship I caught the bug to get a Pro class MOA car. I started looking at the XR10 and Berg offerings from Dlux, but $850 just for axles to get started was a bit too rich for my blood. RPP had a good sale on Bully II kits and RTRs for Black Friday, so I ended up picking a Bully II RTR up for $480 which I figured was a good start even if I would probably end up replacing most of the components over time since just the axles from RC4WD are $365.
I did not take any pictures of the Bully II as it arrived, but everything you'll read or watch on the internet is true. The build quality is atrocious, and the setup is terrible. I tried just driving around my living room and it was basically undrivable since even with the end points set on the joke of a servo RC4WD provides, the tires would get caught on the shocks and lower links and lock the front axle up. There were also several screws that were very loose, and the screw attaching one of the lower links at the axle was almost falling off it was backed out so far. Just plan on tearing it completely down so that you know all the screws are tight with thread locker and can adjust the chassis so that it is drivable. I have never owned an RC4WD vehicle before, but I can't believe they sell RTRs if they ship them out this poorly assembled. The parts and design overall seem decent despite the build quality.
The tires were blown up like balloons (I live at 7000') so the first thing I did was vent the wheels. I drilled six holes in each of the internal clamping rings, and now the tires vent great.
While I was taking things apart, I decided to weigh a few things.
Rear axle:
Chassis with electronics and suspension minus axles:
I reassembled the rear axle with a 12T pinion I had in my stash in place of the stock 14T pinion to give the rear 16.7% underdrive since I can't do any motor mixing with the single ESC setup or my FS GT5 transmitter for that matter.
The weight of the rear axle reassembled with the motor this time:
I turned my attention to the front axle next. As I mentioned earlier, the front tires were binding up on the links and shocks, so my main goal was to rectify that situation. The Bully II axles have splined ends that allow you to clock the Cs like XR10 axles and AR60s, so I ended up clocking the Cs to the maximum positive caster position to help the inside tire swing down under the lower links instead of into them. This caused the tie rod to bind up on the axle housing, so I shortened some RC4WD offset rod ends I already had to help the tie rod clear.
I added some steering stops by just using a longer SHCS with some spacers for the tie rod. This stopped the knuckles from turning just before the axle shaft joints bind. Unfortunately, the tie rod binds on the axle housing turning left just before the steering stop hits limiting my steering to the left ever so slightly, but it is not noticeable. Note, the picture does not show the Cs clocked to the maximum positive caster position where I am running them, but it does show the offset rod ends I am using and the steering stop.
I replaced the garbage stock servo with the NSDRC RS700V2 I won at the state championship and I mounted it from below to get it down a bit lower than stock.
The weight of the front axle with the servo and motor installed:
I tried swapping in the softer springs that came with the Bully II RTR, but they limited travel compared to the standard springs that came in the shocks, so I ended up sticking with the stock springs and filling the shocks up with 20wt oil.
I ended up using the Spectrum Firma 70A ESC that came on my Axial Gilamon AXP8 in place of the RC4WD Outcry III that came on the Bully II RTR since it could fit down on the chassis skid plate with some minor trimming and had the correct bullet connectors on it for the RC4WD Rocker Dig. I don't think it is really a performance improvement over the Outcry, it just packaged better.
One of the two tabs trimmed to get it to sit down in the skid:
I didn't take any good pictures, but I 3D printed a part that replaced the metal hex standoffs on the chassis skid plate between the lower links and mounted all of the electronics to the skid plate. I also swapped the stock receiver out for an FS2A so I could use my FS GT5 transmitter. There is still way too much wiring I had to bundle in the chassis.
I painted the panels with the same tan color I used on my Sporty and 1.9 trail class rig and I also 3D printed a battery mount that allowed me to rotate the battery 90° so it would clear the tire when turned. I am running the Tattu 650mAh 3S packs I run in my 1.9 trail class car for now. I also unthreaded the upper links 4 turns in the rear and 2 turns in the front to help raise the motors up. I moved the lower link/shock mounts to the inboard position on the front axle to help with tire clearance when turned as well, but that requires me to move the lower end of the shock to the outside of the axle mount due to clearance issues with the servo. This required me to pace the chassis side of the front shocks out quite a bit more than stock to keep them from binding during articulation. Here it is just before its first competition with only 1 battery pack worth of drive time on it:
I was worried about even being able to finish courses since I didn't have any knuckle weight, but the Bully II ended up surprising me and I finished in 4th place and completed every course. I need to revise my battery mount slightly since my battery popped out after a hard roll and cost me 10 point to fix it which would have put me dangerously close to 3rd place. I think Pro might be my favorite class to drive now.
Waiting to start the last course:
Results:
I did not take any pictures of the Bully II as it arrived, but everything you'll read or watch on the internet is true. The build quality is atrocious, and the setup is terrible. I tried just driving around my living room and it was basically undrivable since even with the end points set on the joke of a servo RC4WD provides, the tires would get caught on the shocks and lower links and lock the front axle up. There were also several screws that were very loose, and the screw attaching one of the lower links at the axle was almost falling off it was backed out so far. Just plan on tearing it completely down so that you know all the screws are tight with thread locker and can adjust the chassis so that it is drivable. I have never owned an RC4WD vehicle before, but I can't believe they sell RTRs if they ship them out this poorly assembled. The parts and design overall seem decent despite the build quality.
The tires were blown up like balloons (I live at 7000') so the first thing I did was vent the wheels. I drilled six holes in each of the internal clamping rings, and now the tires vent great.
While I was taking things apart, I decided to weigh a few things.
Rear axle:
Chassis with electronics and suspension minus axles:
I reassembled the rear axle with a 12T pinion I had in my stash in place of the stock 14T pinion to give the rear 16.7% underdrive since I can't do any motor mixing with the single ESC setup or my FS GT5 transmitter for that matter.
The weight of the rear axle reassembled with the motor this time:
I turned my attention to the front axle next. As I mentioned earlier, the front tires were binding up on the links and shocks, so my main goal was to rectify that situation. The Bully II axles have splined ends that allow you to clock the Cs like XR10 axles and AR60s, so I ended up clocking the Cs to the maximum positive caster position to help the inside tire swing down under the lower links instead of into them. This caused the tie rod to bind up on the axle housing, so I shortened some RC4WD offset rod ends I already had to help the tie rod clear.
I added some steering stops by just using a longer SHCS with some spacers for the tie rod. This stopped the knuckles from turning just before the axle shaft joints bind. Unfortunately, the tie rod binds on the axle housing turning left just before the steering stop hits limiting my steering to the left ever so slightly, but it is not noticeable. Note, the picture does not show the Cs clocked to the maximum positive caster position where I am running them, but it does show the offset rod ends I am using and the steering stop.
I replaced the garbage stock servo with the NSDRC RS700V2 I won at the state championship and I mounted it from below to get it down a bit lower than stock.
The weight of the front axle with the servo and motor installed:
I tried swapping in the softer springs that came with the Bully II RTR, but they limited travel compared to the standard springs that came in the shocks, so I ended up sticking with the stock springs and filling the shocks up with 20wt oil.
I ended up using the Spectrum Firma 70A ESC that came on my Axial Gilamon AXP8 in place of the RC4WD Outcry III that came on the Bully II RTR since it could fit down on the chassis skid plate with some minor trimming and had the correct bullet connectors on it for the RC4WD Rocker Dig. I don't think it is really a performance improvement over the Outcry, it just packaged better.
One of the two tabs trimmed to get it to sit down in the skid:
I didn't take any good pictures, but I 3D printed a part that replaced the metal hex standoffs on the chassis skid plate between the lower links and mounted all of the electronics to the skid plate. I also swapped the stock receiver out for an FS2A so I could use my FS GT5 transmitter. There is still way too much wiring I had to bundle in the chassis.
I painted the panels with the same tan color I used on my Sporty and 1.9 trail class rig and I also 3D printed a battery mount that allowed me to rotate the battery 90° so it would clear the tire when turned. I am running the Tattu 650mAh 3S packs I run in my 1.9 trail class car for now. I also unthreaded the upper links 4 turns in the rear and 2 turns in the front to help raise the motors up. I moved the lower link/shock mounts to the inboard position on the front axle to help with tire clearance when turned as well, but that requires me to move the lower end of the shock to the outside of the axle mount due to clearance issues with the servo. This required me to pace the chassis side of the front shocks out quite a bit more than stock to keep them from binding during articulation. Here it is just before its first competition with only 1 battery pack worth of drive time on it:
I was worried about even being able to finish courses since I didn't have any knuckle weight, but the Bully II ended up surprising me and I finished in 4th place and completed every course. I need to revise my battery mount slightly since my battery popped out after a hard roll and cost me 10 point to fix it which would have put me dangerously close to 3rd place. I think Pro might be my favorite class to drive now.
Waiting to start the last course:
Results:
Last edited:
