Review: Losi XXX-SCT Brushless RTR with AVC

You might look at the Losi XXX-SCT on these pages and think “great, another 2WD Short Course truck”. In some respects, you’re right on target. It is a 2WD truck based on the XXX-SCT platform, it is powered by a pretty stellar Dynamite 3300kV and 45A ESC and it does come with a Spektrum DX2E 2.4GHz radio system. All this (and some of its other features) do put this SC on par with other trucks in its class. So, what am I going to tell you that’s going to make you want to purchase this truck? Simply put, it’s 3 little letters – AVC.

AT A GLANCE
WHO MAKES IT: Losi
WHO IT’S FOR: Everyone
PART NUMBER: LOS03002
HOW MUCH: $349.99
BUILD TYPE: RTR

FACTS
• The XXX-SCT chassis has seen quite a few years of service both on and off the track. Molded out of composite plastic, the sides have been designed with a slight upward angle, helping to eliminate any chassis touchdown during hard cornering or landings. The central battery box cradles the included 3000mAh 2S LiPo battery nicely and features five foam pads that allow you to position the battery in a multitude of positions for tuning weight bias. To hold the battery in place, a long molded battery strap is used which also helps reduce longitudinal chassis flex. It’s a great platform for this RTR and there are quite a few aftermarket goodies available for it.

• The suspension system, like the chassis, has been thoroughly tested throughout the life of this platform. Strong, lower composite suspension arms stretch out to composite caster blocks up front and hub carriers out back. Shiny, steel turnbuckles are used for adjusting camber and toe. Beefy, molded towers offer plenty of shock tuning, camber link and roll center adjustments. Aluminum shocks are included and if you’re an old-timer like me, these might look familiar to you. These were probably the first bottom-load shocks available and came on Losi’s JRX2, so this design has been around a long time. Don’t get me wrong, these work great, but in today’s world of big bores and threaded everything, a fresh set of dampers would be an awesome selling point.

• The steering on the XXX-SCT utilizes a dual bellcrank setup that is, unfortunately, not bearing supported. A set of plastic bushings is used instead, but that doesn’t seem to affect the overall operation one bit. I didn’t sense any wandering or sloppy feeling, but I would suggest keeping an eye on this area and making sure it’s kept clean. Powering the whole steering system is Spektrum’s S6170 digital servo. This servo only boasts 65 oz. of torque, but since all the weight of this SCT is over the rear tires, this servo had no problem keeping up with my inputs.

• The XXX-SCT’s drivetrain revolves around an efficient and compact transmission. Mounted behind the shock tower (in RM, or Rear Motor layout), this transmission utilizes a set of race-bred CVD’s to feed the power of the Dynamite 3300Kv brushless motor to the hungry Eclipse treaded tires. It also comes loaded with an adjustable slipper clutch to tame the XXX to different track conditions. The entire truck rolls on precision ball bearings for effortless forward motion.

• We couldn’t finish up the Feature section without mentioning the main attraction of the XXX-SCT, the AVC. AVC stands for Active Vehicle Control; basically a sensor system that can adjust the steering and throttle faster than you can. Think of it as a gyro for your RC car, or a form of traction control. If the vehicle’s onboard AVC sensors detect any sliding or spinning, the AVC automatically takes over the steering and throttle to keep the vehicle under control. Over my numerous years of racing I’ve learned both throttle and steering control with many different cars and on all types of surfaces, so I was extremely curious about how the AVC system worked as well as how natural it actually feels.

PROS
+ Spektrum DX2E V3 2.4GHz radio system includes AVC
+ Excellent power with the waterproof Dynamite 3300Kv motor and 45A ESC
+ Slipper clutch, rear CVD’s and 3000mAh 2S LiPo included
+ Platform can be tuned for serious track performance
+ Chassis includes molded looms to keep wires tidy
+ Tires have good grip on most surfaces
+ Aluminum shocks are nice

CONS
– Shocks that are more substantial (and a current design) would be cool
– An updated body with anti-kite cutouts

PERFORMANCE
This was my first experience with a vehicle with any type of traction control system including AVC (Active Vehicle Control), so I wasn’t quite sure what to expect. Before heading to the track, I decided to take the XXX-SCT to the parking lot of our building. It’s been snowing here like crazy, so the ground is completely wet as well as having some residual sand/salt; this should give me a good idea of how this whole AVC system works.

After charging up the 3000mAh 2S LiPo, I gathered the truck, the radio and Greg and we headed outside. I started with the AVC turned all the way down to get a feel for how the truck reacts under normal, un-assisted driving conditions. We started our play time by trying to make a few high-speed passes which were somewhat difficult to do and required some very sensitive throttle inputs to get the truck to stay in a straight line. Once moving, the tires did a great job of holding traction as long as I was going straight. The moment I turned the wheel, it got a bit dicey and I never knew what the truck was going to do. I also noticed that, under hard braking, the XXX-SCT would swap ends before I had a chance to counter the movement. I handed the radio over the Greg and he had the same results; a fine modulation of the throttle and brake to control the XXX-SCT on the wet and slippery surface. Now that we had a baseline for the truck, we turned the AVC all the way up and gave the XXX-SCT another shot on our perilous pavement.

To sum it up quite simply, Losi has hit on an entry level feature that drives their vehicles to the top of the list. This AVC is the real thing; from the moment I mashed the throttle, the XXX-SCT became a completely different truck. From a standstill, you’d swear it was 4WD. Once moving, this truck was pulling wheelies! Even under extremely hard braking, I only had to do very minor inputs to keep it straight. There were only a few times where the AVC couldn’t catch the truck, but for the most part it’s not a matter of point and shoot. Greg and I were both amazed at the performance, especially the wheelies! I handed the radio over to him and he proceeded to dump the battery, but not until he drove this truck as hard as he could. He was also able to overpower the AVC, but it took a lot to do so.

Now that we knew what we were in for, we packed up our gear and headed to the track to see what the XXX-SCT could do on a prepped surface. On a fully charged LiPo, I set the truck on the track and turned the AVC all the way down. I gave the truck a full pack and found that, while it is very fast and handled pretty well for an RTR, the biggest drawback was the tires. These are not the preferred tires at Wolcott Hobbies, so it did take a few laps to get into a groove to put down some consistent laps. The Dynamite electronics package is pretty powerful and had me on my toes lap after lap, but the overall handling was acceptable. I know for a fact that if a good set of race tires were mounted up and a little tuning in place, this truck would be able to fly around this track, AVC or not. But, thankfully, all I had to do was twist this little knob on the transmitter and, wah-lah, instant super truck!

A fresh pack went in and the XXX-SCT was back on the track, this time with the magic dial turned all the way up. Again, the truck went from just driveable to zeroed-in, and it took no time at all to start flying around Wolcott’s raceway! I did have to manage the throttle a little more than I did on the pavement, but the AVC made the truck so forgiving that, even on the stock Eclipse tires, it was easy to drive. This system does take away the ability to throw and slide the truck around, but remember it is adjustable, so you can roll it up or down to fine tune its sensitivity. After a couple tweaks I found a good setting and that’s where it stayed the rest of the day.

SPECS & TUNING OPTIONS
DIMENSIONS
LENGTH: 21.65 in. (550mm)
WIDTH: 11.45 in. (291mm)
HEIGHT: 7.48 in. (190mm)
WHEELBASE: 12.95 in. (329mm)
WEIGHT: 4.7 lbs. (2.04kg)

BODY, WHEELS AND TIRES
BODY: Pre-cut, screen-printed Short Course body
WHEELS: 2.2 in. Multi-spoke
WHEEL ADAPTER TYPE: 12mm hex
TIRES: Losi Eclipse SCT tires

SUSPENSION
TYPE: 4-wheel independent
SHOCK POSITIONS: (F) 4-tower, 3-arm, (R) 4-tower, 3-arm
CAMBER: Adjustable turnbuckles
ROLL: Adjustable ball stud heights
WHEELBASE: Adjustable with shims
RIDE HEIGHT: Pre-load spacers

STEERING
TYPE: Dual bellcrank
TOE: Turnbuckles

CHASSIS
TYPE: Tub
MATERIAL: Molded Composite
THICKNESS: N/A

DRIVETRAIN
TYPE: 2WD
TRANSMISSION: Multi-gear
DIFFERENTIAL: Gear differentials
CLUTCH TYPE: Adjustable slipper
GEAR RATIO: Optional pinion gears
BEARINGS: Full shielded

THE LAST WORD
There are many attractive elements to Short Course trucks; their look, especially if they’re decorated in realistic liveries, the huge body to allow some ‘rubbing is racing’ contact and the fact that they handle really well. The XXX-SCT is a platform that delivers. As an RTR it includes everything you need to go from box to bumps in no time flat; a race-proven chassis that is very competitive, a brushless system, LiPo battery and even a 2.4GHz radio system … all included! Mount up a set of race tires, do a little tuning and a podium finish is easily achievable. Now, throw in the AVC system and we’re talking about a completely different truck; a tool to help beginner’s go fast.

LINKS
Losi losi.com, (877) 504-0233