WLToys 104072 Hoonitruck Review and The Free fixes Needed to make it Driveable

The new WLToys 104072 is a 1/10 scale onroad "basher" truck. It is ready to run (RTR) and includes radio and powerful brushless power system. For those familiar with the WLToys models it is based on a modified 104001 / 104002 chassis and includes a well-proportioned resto-mod truck style body like Ken Block's Hoonitruck. Closer to the RC world we've seen this design on the larger Arrma Infraction and even the small scale WL Toys 284131. This truck is designed to be driven hard onroad.

On road bashing is a category that has been made popular by the 1/7 scale Arrma Infraction and Felony and more recently by the slightly smaller 1/8 Infraction 3s and Vendetta. This 1/10 scale 104072 by WL Toys looks to take advantage of that new market with a similar look on their 1/10 scale chassis. The underpinnings are based on the brushed 104001 (reviewed here) and brushless 104002 (reviewed here) that have been extensively modified from their buggy origins to a lower, narrower and strengthened onroad-only chassis with the 104072. In this review I'll look more closely into the systems that make up the car and then review it as a whole for driving experience. 

I'll let you know now that driving experience out of the box was not great but I've recommend some simple and inexpensive/free changes that resolve these handling issues. First let's look at what's included. 

What's in the box?

Like most WLToys RTR vehicles the focus is value for money so you'll get the key items needed to run and very little else:

• The car of course
• 2.4GHz digitial transmitter (the "v2" long range version)
• A 2s 3000mah lipo battery
• USB charger
• Manual
• Body clips
• Wheel nut removal tool.

A Closer Look at the Gear

As usual we'll take a closer look at the car and I'll discuss how this setup will affect performance and durability.

Power Train. The 3650 4500kV motor and 45A brushless ESC is the same power system as used on the WL Toys 104002. These are manufactured by Surpass Hobby and yes, you can use the surpass hobby programming card to adjust ESC parameters as shown here. On face value 45a seems light for the ESC rating (I'd prefer 60a) but it seems to do the job ok and can even manage 3s for short bursts although you do so at your risk. The ESC has an always-on active fan and the motor has a large passive heatsink. By comparison the larger Arrma Infraction 3s (1/8 scale) uses a 3660 motor (10mm longer) at 3900kV albeit on 3s with a 100A ESC.

The stock 3650 4500kv motor is an appropriate size and the kv is suited to 2s

The ESC is a surpass hobby 45a model which is a little light (in my opinion) for regular 3s operation

The battery is a 2s 3000mah lipo which is a good size to get started with and there is provision to fit a larger battery if needed. 

There is plenty of room around the ESC and motor so scope to fit larger units if needed. More importantly for me there is room to move them around in the chassis which I'll cover off later.

Drive train. Like the 104001 and 104002 the drivetrain on this car is defined by a strong but heavy spur gear spool in 0.6mod pitch. This creates a lot of rotating mass and can act as a flywheel, dampening throttle response somewhat. The pinion gear is 27t and larger than that found in the 104001/2 to account for the smaller wheels. There are plenty of pinion gear size options as you can see here due to a common gear pitch and adjustable motor mount.

Stock spur spool is heavy but well made and the gear mesh is clean

Common 0.6mod hearing and adjustable mount means there are a lot of gear ratios available

Moving out from the spur, power is transferred front and rear with floating propshafts with metal bevel pinion providing power to the front and rear.

Individual front and rear prop shafts are floating which makes this more robust than the 1/12 and 1/14 scale WL toys cars

​There has been comment that the mesh on these pinions is not fantastic and can benefit from shimming. If left unchecked and driven rough this can cause premature wear in the bevel pinion. Internal diff gears are also metal and these are fully sealed. There is a lot of variation to the amount of lube but since they are sealed, you will probably want to use your favourite diff fluid rather than grease anyway. 

Gasket seal on the diff

Orings on the output shafts. Diffs are fully shimmed from factory

Drive cups are reasonably chunky and there are CVD driveshafts in the front and dogbone driveshafts in the rear. Ball bearings are everywhere of course and drive to the wheels is by 12mm hex which is common and what you would expect from a 1/10 scale car like this.

Rear dogbone drive shaft are shorter due to narrow track

Front driveshafts are CVDs

Suspension. Large bore equal length oil filled shocks are used on all corners. They are basically the same as the 104001/2 fronts and like those shocks they have an overly heavy set of springs. Threaded collars make for adjustable car height (to an extent) and there are options for some suspension geometry tuning. Speaking of tuning, all of the tierods are adjustable - front toe, servo horn adjustment and front and rear camber.

Rear

Front

Separate cups, springs. Oil filled body with threaded collar

Suspension arms and associated hardware are shorter making the car narrow and more durable as a result.

Chassis. The Chassis has been heavily overhauled compared to the buggy. The underneath has extensive shrouding and provide smooth airflow just like the Arrma Infraction even to the extent that the rear diffuser should actually be active at high speed. 

The additional shrouding extends to large, flat front and rear bumpers which are build to take a serious hammering and product the body and car. This extends right around the car and should make for some pretty extreme durability. 

WL toys have still turned a blind eye to the flex in the chassis since they are lacking a top brace or properly made chassis stiffeners. This is easily resolved with a cheap carbon top brace or even cheaper 3d printed top brace but a shame this is not included out of the box.

$15 carbon top brace from makerfire

Here it is fitted

Body. The body looks fantastic due to the proportions they have chosen here and looks just like a scaled up version of the 284131 as reviewed here. It has an absolute plethora of lights that is controlled by it's own distribution box that are bright and signal during turning, braking and reversing.

The body is well proportioned here

The LED light distribution box has a better execution here and plugs in to a spare throttle output on the receiver for active brake lights.

The mounts deserve a mention because they are so hefty and the chassis/bumper design means it is thoroughly protected. Even with tumbles rolls and crashes mine has not come to grief.

Body mount design has been copied from the excellent ones on the Arrma infraction and give excellent stable and positive mounting

I love how the tough bumper lip extends just beyond the shell for true protection

Wheels and tyres. Tyres have a 70mm outer diameter which is something of a unique size. Tyre compound is what I would call medium hard and the tread pattern is fairly minimal. Even with a hardish tyre I'd expect this to wear quickly. tyres are well glued to the rim and have a really firm inner foam which keeps the contact area of the tyre to the driving surface consistent. I see WL toys have launched other options for tyres as per their Aliexpress store and I'd expect to see these with other retailers soon..

Wheels seem to stand up to abuse and curb-kissing ok

This shows me the tyres are working hard

The only other onroad style wheel I've found in this size is the drag racing foam front wheels made by contact. The Arrma vendetta runs a 85mm wheel but with 14mm drive hexes, just to be different

Contact drag foams are a direct fit

Arrma Vendetta wheels are a 15mm taller and use a larger 14mm hex

Steering. The steering setup uses a standard 1/10 scale servo with a drag link steering setup that is smooth and precise with very little play. The rack has an adjustable servo saver built that works well. All of the tie rods used are adjustable. There is a fair amount of caster angle and this is fixed. The steering servo is very fast and a definite improvement from the 104001 which used a very slow 5-wire servo. You can make this steering even faster by moving the link to the outside hole on the servo horn but would need an aftermarket radio to be able to dial steering dual rate back. Even as it is there is plenty of steering lock.

3 wire servo is reasonably fast and the steering setup offers excellent lock and very little play

Fully adjustable servo saver

Radio. The transmitter is the tried and tested WL toys standard model with a trigger throttle and foam steering wheel and takes 4 x AA batteries It has fine adjustment for steering trim but not dual rate and throttle dual rate but not trip. The throttle dual rate is a good way of limiting top speed for beginners. This model is the revised "V2" version that has extended range over the model with the silver/grey steering wheel. Overall these are a lightweight but comfortable and reliable unit.

The receiver is a discrete 2 channel unit. The additional plugs are reverse channels for steering and throttle. These receiver is very compact and light and features as short 2.4ghz whip antenna. These are easy to behind and have proven reliable. Range is good for line of sight, I've been past 50m without issue

Hold up, we need to fix the handling

After the first couple of drives it became apparent the handling was pretty awful with the tail regularly sliding out; and not in a good way. It was clear that before continuing the review I needed to fix this. The good news is that I think I largely achieved this and have improved than handling substantially.

Here is the handling before the fixes below

The weight split front to rear is the biggest problem.

This car is really front heavy, I'd say around a 55 front: 45 rear split and for a car with even sized tyres this is just a disaster. It's worth noting that the 104001 and 104002 buggies probably get away with this due to the larger tyres in rear. Anyway in order to resolve the weight split back to around 50:50 I did the following:

The ruler is the fulcrum (weight split) see how far to the right (forward) it is

Move the ESC behind the motor. Cable ties are your friend here to help with moving the ESC behind the motor, not wire cutting is needed. Just remember that the motor wires are stiff - they are really just an external extension of the motor windings. Get some good double side tape (like 3m VHB) and stick the ESC down hard.

Move the receiver back alongside the battery. The receiver weighs very little but moving it back to sit between the battery and motor certainly helps.

Optional: Move to a shorty lipo pack. In this guide I show you how to install a common "shorty" size hard lipo pack in this chassis. If you do this make sure you trim the rear piece of battery tray so that it sits as far back as possibly. Obviously this is just an option if you happen to be looking at larger capacity batteries but it'd be rude not to mention at this point.

The "shorty" battery pack has more capacity, is more durable and is more compact meaning it is easy enough to fit here.

The car sits too high, is over-sprung and under-dampened.

Poor dampening is due to lack of oil. Seriously I thought WL Toys resolved this years ago. Maybe I got a car built on a Friday or something but all four shocks were consistently low in oil. I simply topped mine up with 60wt but I'll be looking at removing the oil and starting fresh with a full cylinder of 60 weight oil. Be aware that my preference is typically for more dampening, less spring. You may wish to go a little lighter, maybe 30 or 40wt.

Spring rate is too hard and I don't have replacements. Ideally I'd have a softer spring to replace these but I don't have any in this size. Being a common 1/10 size you may find something at your local hobby store but you can change the mounting geometry to compensate. 

For the front this is easy, move the top mounts to the inner-most holes. This gives a good effective spring rate and dampening rate, I'm pretty happy with it overall. Even the ride higher is better (lower - it was unnecessarily high due to long, hard springs)

The front left has been moved to the inner hold to reduce effective spring weight

The rear is a little more challenging. An awkward shock absorber mounting angle means you need a much longer M3 screw to hold the shock on at the lower mount and a suitable spacer. I used an M3 x 12mm screw and around 4mm worth of spacers. Not ideal but it tidies up the shock angle, and takes a little off the effective spring rate as well as drops the ride height to a better level. The dampening is still a little light for me but moving to 60wt oil will help I believe.

I used to M3 plastic nuts from my box of bits to get the correct spacing (plus a long M3 screw)

Both rear shocks can now reach the inner tower hold without fouling

Overall this weight split improvement and change to suspension makes a substantial difference and makes it worthy of review. So let's get on to the review...

Performance Review

Top speed and acceleration. I got 58km/h top speed on 2s which I feel is about right. I've seen that others have topped 80km/h with 3s batteries but not something I'd really recommend with a 45A esc. Acceleration is ok without being great. I can't help but feel there is a bit of a bottleneck in here somewhere which I can't help but feel is the battery, possible the ESC. I'll do some further testing and post here when I have results. The large, heavy spur/spindle probably doesn't help either. Like a heavy flywheel on a car it will give the feeling of smoothness over response and this characteristic can greatly change the 'feel' of rapid acceleration. Still this is a decent brushless setup and vastly outperforms anything brushed.

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Handling. If I were to rate this as stock it would go straight to the "do not recommend" pile but with the changes I have suggested above it is actually pretty good. With the weight split more biased towards the rear than stock (It feels around 50/50 now) cornering and acceleration is much more predictable now and the suspension changes have mostly, but not completely fixed the weight transfer issues. Before where I used to spin out on takeoff fairly easily it is much more assured in a straight line. Being near 50:50 high speed cornering actually give a surprising lack of understeer and throttle variation can induce oversteer at will. This makes it much better suited to drifting and certainly a gyro would improve this further yet. In addition some heavier diff fluid would also create resistance in the diff and offer more predictable drift behaviour. Since these are sealed diffs this is easily achieve as you can see in this article. 

Overall I am pleased with the handling now. I plan to make further tweaks later on but happy to drive as is for now. One thing I don't like is that heavy braking tends to make the car plow understeer in a straight line which doesn't suit a drift style car. My thoughts were that a one way diff in the front would really improve this - this would make only rear wheels do the braking while the fronts free-wheel: much like the handbrake of a rear wheel drive car.

Oh yeah, tyre grip is actually pretty good thanks to the firm foam in the tyres. You can see from these pictures to the right that the tyre rubber works hard to keep up. It's a relief these work well because although there are a lot of touring car wheel/tyre packages in 65mm diameter, there is a distinct lack in this 70-75mm range. I might have to play with some stock WLToys 144001 wheels, these are around that size...

Durability. This is one area where I have no complaints. Street bashing is probably the harshest type of bashing because obstacles tend to be fixed in place and very hard - think of curbs, drains and the wheels of parked cars. So far my 104072 has stood up to all of these. The fully enclosed body protects the shocks and shock towers, the shorter suspension arms and shrouds protect the rest of the suspension and the super beefy front and rear bumpers and chunky body mounts protect the body. Ultimately the body will take a hit but I expect replacements from WL Toys to be very cost effective.

Looks. This is not an area I've really commented on before but this car just looks cool doing it's thing. The look of the hoonitruck from Ken Block's excellent Gymkhana series in general has really captured people imagination and this has been well executed (except for perhaps the graphics!!). Furthermore the lights are a lot better thought out than previous WL Toys models (like the 104009 which were a mess) and they add another dimension when driving in fading light.

Conclusion

Overall the WLToys 104072 is a decent budget for street-bashing certainly cheaper compared to the branded alternatives presently available. However, this is only if you make changes to the front/rear weight bias and suspension like I have outlined in this review. Top speed is good for this size at just under 60km/h stock and acceleration is good without being amazing. The ESC does retain some of the delay issues of the 144010, 124017 and 104002 but in my mind they seem to be somewhat improved although I haven't measured so cannot be certain. Steering is fast and accurate and handling is good on the whole but more improvements can be made with further customisation. Probably the high points of this truck would be the looks and the durability - I think this is genuinely the best looking and toughest car that WL Toys has ever made.

Check out my next steps below for what I'd recommend to improve it from stock when I'm ready to throw some money at it.

Next Steps

Thicker diff oil. This inexpensive ($5 or less) mod will mean more resistance in the diff and more predictable traction loss. when driving hard

Gyro/radio. Although you can get a simple $10-$15 gyro like this one to piggyback into the existing radio, I'd recommend going for a budget DumboRC set like this with a gyro built into the receiver or even this more premium Flysky FS-Gt5 model. These allow gyro tuning from the remote on the go but will also improve control range, will allow for faster and more accurate steering. allow you to improve throttle resolution and response and will give you better ergonomics. $30-$80 well spent in my mind.

Springs. I want to find some shorter, softer springs that fit these large bore shocks to replace the current ones. My search starts now.

Battery. As mentioned a shortly lipo will help with but running time and with weight distribution. I am using a CNHL Racing 2s 4900mah pack.

ESC. At 45a rating and a known delay issue, the surpass hobby ESC used here is good enough and not much more. A better ESC like the Quicrun 10BL120 from hobbywing will have less delay, more response, be much smoother and shouldn't be a bottleneck like I suspect the stock one is. It should happily run 3s as well although I don't think that will be necessary with the right 2s gear as mentioned here.

The WLToys 104072 I reviewed here was ordered from Banggood. Ordering from this link supports these reviews.

Remember buying from any of these links in my review/guide supports my page without any cost to you and is appreciated especially since I don't ask for money via patreon and the like. If you want to get involved in this discussion, feel free to join the QuadifyRC Facebook Group Here or like my Facebook page below ↓ ↓ ↓ ​

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Finally, for your viewing pleasure, please enjoy Ken Block's Hoonitruck. If you haven't seen this before? You're welcome