Review: Pro-Line Racing Ambush 4×4 Mini Scale Crawler

Loads of Fun in a Minimum Amount of Space

Being a leader in aftermarket tires and parts, Pro-Line Racing shocked the world when they released their line of 1:10 scale PRO kits. You see, PL had been making so many performance parts that it was only a matter of time until they added a few key components to create their own complete kit. Well, the PL gang is full of surprises – check out their new mini offering that snuck in under the radar; the Ambush 4×4. This 1:25 scale micro crawler comes as a RTR, including the AA batteries for the transmitter. It’s a pocket-sized vehicle with Pro-Line flavor all over it. We got our hand on one (it literally fits in one hand), so read on to find out all the details in the tiny little truck.

Specifics
Product: Pro-Line Ambush 4×4
Part #: 4004-00
Price: $183.96
Recommended For: Anyone that wants to have big fun in limited spaces

-Video Coming Soon-

Features
Chassis
The chassis on the Ambush 4×4 is what you’d expect from a typical crawler, using a steel ladder frame that extends down both sides of the truck. To beef it up a bit, the designers doubled up the 1.5mm plates, giving each frame rail an overall thickness of 3mm. This stiffens up the chassis quite a bit and gives the truck a nice, solid feel. To keep them looking pretty over the long haul, the plates have been Black Oxide coated and strong, scale-looking bumpers are attached at both the front and rear. Grabbing both ends, I gave the Ambush a quick twist-test; there is a very small amount of flex but that’s about it. I’m pretty impressed by how rigid the frame is.

Suspension
Instead of giving this truck a 4-link suspension set up, Pro-Line went with leaf springs on all four corners. These connect the solid axles to the chassis via scale shackles; it’s cool to see them work in such a small size. Friction shocks help with the damping and you’ve probably noticed the lack of a spring; that’s because Pro-Line has designed the shock with an internal spring setup. Out of the box, the setup works great, however the articulation seemed a bit hampered with the current set up. We’ll get more to that in the Tuning section.

One thing to note is that the chassis has multiple mounting locations for the leaf springs as well as a slot to slide the rear shock mount. Yes, the Ambush 4×4 does have adjustable wheelbase; simply change the mounting locations and wah lah – a shorter wheelbase! I’ve been told that optional bodies will be available for the Ambush, so Pro-Line has planned ahead for these. Smart.

Drivetrain
The drivetrain on the Ambush 4×4 is quite unique. A tiny Micro Torque brushed motor is bolted to an aluminum motor plate that is attached to the multi-gear transmission. Plastic universal slider shafts connect to the front and rear axles, both of which are very similar to their 1:10 scale cousins; tiny bearings for low resistance, screw-on C-hubs and lockouts, small cross pins and 7mm hexes at the ends.

Instead of a typical ring and pinion in the axles, though, the Ambush uses a worm drive system to transfer the power to the wheels. So what’s a worm drive and is it any better? In a typical crawler, the transmission transfers the power to the axles via a slider shaft that enters the rear axle housing at a mid-point. A ring and pinion setup then rotates the rear axle to drive the tires. On a worm drive unit, the same slider shaft exits the transmission but instead mounts to the top of the axle, using a spiralled ‘worm’ gear to spin the ring gear that drives the rear axle. The biggest benefit here is the added ground clearance, something this Lilliputian crawler greatly benefits from. As you can see from the picture, both gears are metal, further increasing the durability.

Steering
The Ambush includes a G9000 Micro Servo that has plenty of power to keep the Ambush pointed in the right direction. A tiny servo saver is mounted to the servo’s output shaft to help protect it should you get the front tires stuck. The steering links and steering arms are molded from a very strong plastic to reduce flex. The little free-play that is actually in the steering is mostly from the ball ends.

One thing to watch out for; you can turn the dual rate up quite a bit via the buttons on the transmitter. Turning it up to high can allow the tires to come in contact with the leaf springs, creating a ‘clicking’ sound. I didn’t notice it affecting the performance of the truck, but I turned it down a few clicks to help prevent it. Just something to watch out for.

Electronics
Pro-Line has outfitted the Ambush with a full set of proportional electronics. A 2.4GHz transmitter controls the truck though an integrated receiver/ESC combo that is mounted just above the rear axle. It’s a 3-channel system, so there’s room to add a 3rd channel ‘something’ in the future. Apparently Pro-Line has some 3rd-Channel option parts slated for release – perhaps a mini winch?

The G9000 Micro Servo is a 3-wire servo so if you want to upgrade it at some point it’s a very easy swap. A Micro Torque brushed motor is installed for maximum torque fed by an included 350mAh Lithium battery. The battery comes in a molded hard case with the charge adapter sticking out of one end. It slips in and plugs into a molded battery box resting over the servo and included an integrates on/off switch.

Body, Wheels and Tires
Topping the 4×4 is a Ford Bronco-ish shell dubbed the Ambush Trail Rig. It’s actually a great looking shell with an attractive finish; as you can see mine is the silver with blue accents. Other colors will be available as well.

To add to the scale look, PL has molded the body without a roof, thus allowing a separate, scale-looking molded roll cage to be attached to it. A matching Lexan roof bolts to the cage to keep the sun out of Peter Proline’s eyes; yes, I named him already. He looks pretty cool with his backwards hat and sunglasses.

Of course the the Ambush rolls up on a full set of of PL rubber – Mini Flat Iron tires are wrapped around micro Denali wheels. The tires look great but don’t come with inserts; that’s OK as they have great traction and actually have a little bit of deformation when hiking up and over uneven terrain.

Performance
So where do you go to test a 8″ long crawler? Just about anywhere you want to! I set up a little course in my office, however nothing quite to the extent of what Pro-Line actually did (see their bad-ass video here: https://youtu.be/mzONpp9cUWw). I also did a little crawling across the street from my house – there’s a big park with some dirt-filled planters and a small, dried-up creek that’s loaded with rocks. I charged the battery using the included USB charger (it was actually charging in my computer USB port while I was writing this) and headed out across the street for a ‘little’ fun time. See what I did there?

Speed and Braking
The Ambush has three drive settings – Low, Medium and High – all accessible from a 3-point switch on the transmitter. I did a few 3-4′ acceleration runs to get an idea on the difference in speed; the variation from the Low and High Modes was definitely noticeable. I don’t think I’ll ever use the Medium setting, though, but it’s nice to have just in case.

Starting in the High mode, I cruised around for a bit on the pavement, jumping over some broken concrete and into the dirt and wood chips. I came upon some downed trees (actually just large sticks, but they seemed like scale trees) and tried to climb over them in High mode – it did, but didn’t look very scale as it floundered around trying to get grip. I switched the Ambush into Low mode which doesn’t actually add more torque, it slows the wheel speed down to allow more grip. It indeed worked! It’s really quite cool to watch the mini Flat Irons claw their way over the terrain.

One thing I’d like to also comment on is the brakes. When you let off the gas and return the trigger to neutral, the Ambush stops – like, immediately. Some of this might be electronics, but most of it is the crazy worm drive system. It’s like its got drag brake on steroids. Just be careful when descending steep slopes or you’ll end up at the bottom right quick.

Steering and Handling
The steering on the Ambush is good, however it takes a bit of space to make a full U-turn. If you’ve ever owned a crawler, you know that the turning radius on these things can be pretty wide due to the front locked differential. Over several tries in both directions, my best was a 28″ radius. However, if you’re out crawling on rocks, dirt, etc, you’ll probably be doing alot of multi-point turns so this isn’t that big a deal.

As far as the handling, the Ambush reacts as you’d expect from a crawler. It treks over most mild terrain with ease while the leaf spring suspension absorbs any irregularities. Small inclines are no problem; using the Low Mode, the Ambush slowly grips the terrain and walks all over it. You’ll want to use some caution when trying any steep or side-angle stuff. It’s designed as a scale crawler, so the CG (Center of Gravity) is a bit high. That means it can topple over if you’re not careful. Be smart about your ascents (and descents) and you’ll be good to go.

Durability and Maintenance
You’ll notice how I mentioned to be smart in the above paragraph. Well, I don’t always take my own advice so of course I tried to tackle terrain that was a bit over the top. The Ambush fell, rolled and bounced on many occasions. I was initially concerned about the body constantly coming off seeing as it’s only held on with Velcro, but I am pleased to say that I didn’t have this issue, not even once. It’s still a concern (especially with the amount of times I’ll be taking the body on and off), so I might try and find an alternative method of mounting but for now it’ll be a-ok.

As far as maintenance, there’s really not a whole lot this little truck needs. Everything is well protected, the shocks don’t need re-filling and the tires should last a long time. Speaking of the tires, I found it quite interesting that the outside of the tires are completely glued to the wheels while the insides are just ‘kind-of’ glued. What I mean is that the insides are spot-glued, probably because there are no vent holes in the wheels and this allows any trapped air to escape.

Tuning
The suspension can be tuned in a couple of ways. The Ambush uses three leaf springs per corner; removing one (or two) will allow the suspension to flex quite bit more, giving better articulation. The shocks can be tweaked as well by removing the inner spring. This might drop the ride height a tiny bit but will provide less resistance and further add to the articulation.

Tire tuning, well, this is Pro-Line, so aftermarket rubber will surely be available at some point.

Additional

Spec Data

Conclusion
Pro-Line’s Ambush 4×4 is a fantastic entry into the small scale world for the tire manufacturer. It’s fun, looks great and their history of the aftermarket means they’ll probably continue to support it with fresh upgrades for quite some time. This will undoubtedly keep people interested as well as provide them with ways to constantly customize their micro rigs. I also love the fact that, because of it’s size, I can create a course pretty much anywhere I want. Great job Pro-Line.

Features – 9
Appearance – 10
Performance – Speed & Braking – 9.5
Performance – Steering & Handling – 8.5
Performance – Durability & Maintenance – 9
Performance – Tuning – 8.5
Overall Value – 9.5

Connect
Pro-Line Racing, www.ProlineRacing.com

Gallery