If you frequent the T-Maxx forum, you’ve probably already read through a review of mine. If not, let me bring you up to speed. My name is Eric, but many of you who frequent the Traxxas site probably know me through the online forums as Misbehavin’. Altogether, I’ve spent over 10 years in the RC hobby. Much of that time has been spent as an avid Traxxas fan, actively participating in the forums by discussing some of my favorite vehicles to drive.

After having taken the time to detail my experiences with the T-Maxx 3.3, Traxxas thought it would also be helpful and informative for their customers to have someone write up a report on the Revo 3.3 from a user’s perspective. Before long, I found myself tearing through another Traxxas-bred monster truck to show you exactly what it offers on the workbench and at the track!

The Revo is the truck that continues the racing traditions that the T-Maxx made so widely popular. The T-Maxx caused monster truck racing to become a genre of its own, but it was the Revo that took this new facet of the racing scene to a whole new level. It’s the overwhelmingly dominant vehicle found in the monster truck racing scene, and for good reason. It was born with the goal of pushing the monster truck platform to new limits. Follow along as I set off to see exactly what has changed with the Revo 3.3, the most recently released version of this trackside terror!

I always take the time to walk through the various components of the truck, first-off, I want to point out that this will be a two-part review. First I will cover the Revo 3.3 in its box-stock form. Then, in Part Two, I will take a look at the optional center differential and rear brake kit. These are items that many racers have been anxiously awaiting, and they deserve their own space without interfering with the article intended for someone looking for what the truck offers out of the box.

Keep in mind that all of the pictures below will open to larger versions for a closer look. In addition you’ll find several pictures of the Revo 3.3 in action, as well as some video towards the end of the article. Now, let’s get started!

In recent years, Traxxas put themselves leaps and bounds above other manufacturers when it comes to their included documentation. The Revo 3.3 is no exception to this. The Revo 3.3 Owner’s Manual is top notch. If you find plain black and white manuals bland and boring, the Revo’s manual will suit you just fine. Its glossy colored pages seem more like a magazine than a manual. Not only does it get you up and running, but there’s a ton of information that will help you get the most enjoyment from your truck. The majority of topics that most owners have questions about are answered in the manual. In other words, by reading this manual, you are ahead of the learning curve before you even fire the truck up for the first time.

Despite how informative the 47 page Owner’s Manual is, the information to help you out doesn’t stop there. Traxxas also provides you with another manual that covers the warranty information and has the exploded diagrams of the truck. In fact, the exploded diagrams cover six pages in this manual, and they cover every possible facet of the truck you need to know about. Even seasoned hobbyists, such as me, still find the exploded diagrams a very indispensable tool. I keep copies of both the manual and the exploded views in my field bag at all times.

There are also a few other noteworthy items that are included to help you out. These include a quick reference tuning and break-in card, a comprehensive break-in and tuning DVD, and a Traxxas main-line catalog. The tuning and break-in card is just what it sounds like. It’s a quick reference to the basic details for the break-in procedure, as well as the basics for tuning your truck. It is not a replacement for the manual, so definitely make sure you read the manual first.

The manual is probably the most valuable resource you’ll have regarding the Traxxas Revo. However informative it is though, it’s still not a substitute for seeing the break-in and tuning procedures firsthand. For this reason Traxxas includes a DVD to allow you to see the operation of their nitro-powered lineup in action. Seeing and hearing the vehicles in action can be a huge benefit for the newcomer to the hobby. Just remember that, like the tuning card, the DVD isn’t a substitute for the manual, either. To obtain the best overall experience with your Revo 3.3, read the manual and then watch the DVD. The DVD includes a walkthrough of the Traxxas lineup, and you’ll also find a printed catalog in the documentation packet, in the event you’re looking to expand your collection.

The Revo 3.3 arrives with a richly detailed body that sports a tribal-based design. There are four base colors to choose from: black, blue, red, and yellow. My Revo 3.3 was the yellow version, which is excellent, as it is easily visible on the track. In addition to being well detailed, the body also arrives with all of the necessary cutouts and holes already in place and the main stickers already applied. This leaves you ready to put the truck in action, unless you feel the need to decorate the body with more of the included decals.

Yes, I mentioned extra decals, and you’ll be pleased to know that Traxxas supplies you with a large assortment of extras. I usually stash most of these away and use them on replacement bodies at a later point in time. I’m pleased to see that the large single sticker sheet has now been split into two sections, making it much easier to store. Just as you would expect, the stickers are brightly colored, and well detailed. You’ll easily have plenty for several bodies!

If you’ve purchased a Traxxas model within the last few years, you’ll likely recognize the handheld portion of the EZ-Start system. The EZ-Start system used by Traxxas allows you to get your truck up and running quickly, without the need for pullstarts and glow igniters which can often frustrate newcomers. With the EZ-Start system, you simply power the handheld starter with a standard 6-cell battery, push the starter into the socket on the Revo and press the button. It’s that simple!

While you probably have seen the handheld starter, the included Traxxas TRX Power Charger may be an item you have not seen before. The original Rx Power Charger was first included with the introduction of the Revo nearly two years ago. Since that time it has served Revo owners well, providing a simple and effective way of charging receiver packs. My original Rx Power Charger certainly lives up to that, as I’ve used it to charge every receiver pack I have on a regular basis. However, Traxxas found room for improvement in the form of a new TRX Power Charger that can now charge 6-cell 7.2V NiCad and NiMH battery packs in addition to NiCad or NiMH receiver packs. The new charger also includes an adapter for charging 6-cell battery packs that are used for the handheld starter. The new TRX Power Charger now has the ability to handle all of your charging needs.

The TRX Power Charger will charge a typical 1100Mah receiver pack in about an hour. You’ll need to allow around 1 hour and 45 minutes to charge a typical 1500Mah stick pack for the EZ-Start handheld starter. The indicator light on the charger let’s you know when the charging cycle is complete, or if it’s still charging. In the event you wish to mount your TRX Power Charger to your work table, Traxxas has even provided you screws for that purpose!

Believe it or not, we’re just getting started on the host of accessories you’ll find contained within the Revo’s box. Next up is the air filter. While the truck comes with an air filter pre-installed on it, Traxxas has provided you with a spare oiled element and extra filter oil. Knowing that the break-in process alone pushes you to the maintenance interval for the air filter, Traxxas thought this was a wise addition to the accessories included with the truck.

If you like playing in rougher terrain with your monster trucks, then you may want to pull out the bag containing the Long Travel suspension components. While the P2 rocker setup is the perennial favorite of the Revo crowd, and now comes as standard equipment on the truck, the Long Travel rocker setup provides the Revo with even more plush suspension travel. The Long Travel rockers extend the reach of the suspension to 120mm, which is unheard of for an out of the box model of this nature.

The accessories keep coming, with Traxxas throwing in a basic yet thorough toolset to assist you when it comes to working and tuning the various components of your truck. I frequently use the 8mm wrench for adjusting the slipper clutch, and I use the gray shock and pivot ball tool very frequently, as well, with my Revo 2.5.

Speaking of suspension tuning, Traxxas also includes a variety of suspension tuning shims to maintain the elimination of bump steer when changing to the Long Travel rocker setup. Being able to eliminate bump steer is one of the big advantages the Revo platform, and Traxxas still makes it easy to adjust this right out of the box. Other small items you’ll find along with the tuning shims are several spare body clips, foam body washers, and accessories to help you prepare the receiver’s antenna for use.

The Traxxas TQ-3 AM radio is again standard equipment with the Revo 3.3. The three-channel TQ-3 is a sturdy, proven system that includes electronic trim controls, servo reverse, high power output for long-range performance, and an ergonomic grip with the integrated 3rd channel rocker switch. While some may prefer to see a high-end radio as stock equipment, using a simple, reliable AM radio allows the truck to pack as many features onto the chassis as possible while still maintaining an affordable price. The TQ-3 will reliably serve most peoples needs, and then they can choose what’s right for them when it’s time for an upgrade.

If you’re already familiar with the Revo, you’ll feel right at home with the Revo 3.3. While the increased length of the 3mm chassis is quickly noticed when you pull it out of the box, all of the design and innovation that made this such an incredible platform is still there. The rear-mounted engine is angled inward to help lower the center of gravity, which is also the goal of the sides of the chassis. This explains their lowered stance. The pipe placement at the rear of the truck keeps the chassis cleaner than the standard side-pipe configuration does, while hex head hardware holds all of the truck’s components solidly together.

Underneath the truck, a few things give away the lengthened chassis of the Revo 3.3. One is the longer driveshaft at the front, which is the same driveshaft that’s used at the rear. The Revo 2.5 used a much shorter front driveshaft. The turnbuckles connecting the steering assembly to the servos have been lengthened, as well. It’s easy to notice that the lengthened chassis opens up some of the chassis areas that were much more crowded on the original Revo.

As before, the Revo 3.3 offers a flywheel opening which allows for the truck to be used in conjunction with starter boxes. For those of you using a starter box that uses the steering servo skids for placement, such as the one offered by RD Racing Products, rest assured that the Revo 3.3 will still work perfectly with your box. A lot of previous Revo owners are sure to appreciate this fact!

The Revo’s chassis is a work of art and now it’s even better, thanks to the 30mm increase at the front of the truck. Before, aftermarket manufacturers looked for ways to add to the wheelbase of the truck by various means. Many of these solutions used weaker grades of aluminum or used two chassis plates. The result was unsightly welds at the seams, a weak chassis, or an excessive price. In the end, it was the Traxxas team who designed the truck that came up with an extended factory chassis that provides the increased wheelbase and stability that their customers wanted, in one neat package.

When looking at the Revo’s chassis, it’s easy to see that a low center of gravity was a primary concern during the development stages. Aside from the lowered sides, the chassis also sports recessed areas for the rear shocks and differential. These areas allow the chassis to sit low and the components mounted to it to sit low as well. The end result is a very well balanced vehicle that has taken the monster truck racing scene by storm since its initial introduction.

With the addition of the new TRX 3.3 powerplant, Traxxas decided to provide some additional bracing around the engine mount of the Revo 3.3. A separate brace fits around the engine mount and extends forward to the rollbar mounting position. The brace is curved at its outer edge, to provide even more strength than a basic flat brace would. The end result is an engine mounting location that boasts increased strength to handle the additional torque and loads placed on the chassis by the new .20 cubic inch engine. The aluminum engine mount still offers the same adjustability as before, and the engine can be easily removed without altering the gap between the clutch bell and the spur gear.

The front of the Revo differs from the front of most trucks you’ll find. One of the most notable differences is the lack of shock towers because of the rocker based suspension setup. With the absence of vertically mounted shocks, there is no need for a true shock tower. However, there’s still a need to mount the truck’s body.

The main part of the mount rises from the front of the truck and extends towards the rear offering some protection for the front rockers. At the rear of the mount, you’ll find squared-off body posts. These posts are adjustable to accommodate the various aftermarket lexan bodies you may want to mount on the truck later on in the future.

I’m a big advocate for adequately protecting the front of a vehicle with a bumper. The bumper and mounting assembly should provide protection but also flex to cushion an impact. A solid bumper assembly does nothing more than transfer force to the rest of the truck resulting in broken parts.

Traxxas knew this when designing the Revo, so you’ll notice the oval-shape of the bumper brace. This brace flexes when the bumper is hit, and in doing so it absorbs the impact to help prevent the stress from being transferred to the rest of the truck. As someone who has been running a Revo for nearly two years, I can attest to the fact that the bumper setup on the Revo works very well and saved the front end of my truck on numerous occasions.

Continuing the theme of protecting the truck’s components is the factory installed rollbar. This plastic bar rises up over the engine and carburetor protecting them in the event the truck rolls or flips, while also serving as a convenient carrying handle. On the right-hand side of the bar, fuel line clips are molded into its side, which helps to hold the fuel line in place. As a reminder for proper air filter maintenance, you’ll see a notice regarding the proper maintenance interval placed on top of the rollbar.

The fuel tank for the Revo is easily recognized thanks to its angled lid assembly. The tank holds 125cc of fuel, and has a built-in bronze filter at the pickup inside the tank. A spring-loaded lid with a ring-style handle allows you to easily re-fuel the truck and have it back in action with very little time lost. Two small clips hold the fuel tank to the chassis, making removal for cleaning a simple and easy task.

The Traxxas recommended method of shutting off the engine is to pinch the fuel line, stopping the flow of fuel. With the Revo 3.3, Traxxas makes things easy with a pincher clip to accomplish this. Simply snap the clip shut, and the engine will stall within a few seconds. This is a very nice touch.

I mentioned the 30mm extension to the chassis earlier, but a close-up of the area right behind the front shocks really showcases this change. Before the servo wires ran along the shock mount, but now they simply cut across the bare chassis, held in place by plastic clips. There’s a lot more room here, and any Revo veteran should easily spot this change from the original, standard version of the chassis.

The Revo’s suspension is an example of the innovative engineering that sets Traxxas apart from the other manufacturers in the industry. A progressive-style suspension offers you the best of both worlds, first giving you a softer travel range to keep the truck composed over ruts and small bumps. Then as the jumps get larger, the tension rate of the suspension increases to help prevent the truck from bottoming out.

The unique nature of the suspension approach used by the Revo results in some very specialized parts for the truck’s suspension components. The upper suspension arms for the front are molded to take the rockers' pivot range into account and are therefore individually molded for each specific side of the truck. The lower arms are specifically made for each side of the truck, as well, as they need to take the pushrod and larger axles into account. The upper arms are developed to provide adjustability of the truck’s caster angle from a range of 5° to 15°. Caster angle changes are made by moving the plastic c-clips on the upper suspension pins.

The Revo uses a pivot ball approach for the suspension arms, which adds even more flexibility to the truck’s handling characteristics. A pivot ball suspension allows you to easily alter the camber angle of the wheels to suit you tastes or the track conditions. To keep dirt and dust from reaching the pivot balls, Traxxas equipped the Revo with blue silicone dust boots that fit over the threaded ends of the pillow balls. Plastic clamps securely fasten the boots to the axle carrier. Traxxas also fits smaller silicone caps into the outer side of the axle carrier, to prevent any dirt from reaching the pillow ball from the opposite side of the carrier. The caps have slots in them, which allows you to adjust the camber angle of the truck without having to remove them. Traxxas also provides a tool that lets you remove or tighten down the pillow ball caps without needing to remove the caps.

The Revo 3.3 uses a standard 14mm hex adapter and 2.5mm axle pin to connect the wheel to the 6mm axle stub. The axle stub passes through a pair of bearings housed in the axle carrier. The inner bearing is 12x18x4mm, while the outer bearing is 6x12x4mm. The inner bearing’s larger size, allows it to fit over the end of the universal joint securing the pin that holds the axle stub in place. The u-joint of the Revo uses a series of pins and e-clips to fasten the eared yokes together. This eliminates the need to bend and press the plastic yokes around a standard ball-style universal joint.

The main body of the axle follows the large diameter size that’s used with the Revo 2.5. It also uses a multi-spline approach that we’ll see an example of later. This axle is one of the most solid designs I’ve seen to date, and their ease of use surpasses CVD-style units that require much more frequent maintenance intervals. I’ve found that the Revo axles are just as strong, too. They are also able to reliably work with Revo’s huge 120mm suspension travel when the long travel rockers are installed. An accordion-style silicone boot covers the connecting point for the two axle halves, shielding it from dirt and dust.

The rear suspension differs slightly from the front in regards to the upper and lower arms. The upper and lower rear arms differ from each other, being designed for their respective positions. However, unlike the front, there are no individual left and right side parts. The parts can be used on either side. As an additional note, should you feel that the extended chassis on the Revo doesn’t add enough wheelbase to the Revo for your liking, Traxxas offers an optional set of rear suspension arms (part #5333R). These optional arms swing back, and provide up to another 19mm of additional length to the Revo’s wheelbase. That’s in addition to the 30mm provided by the extended chassis found on the truck.

Both the front and rear suspension feature a captured suspension pin approach. This eliminates the need for screw-style suspension pins, and traps the suspension arms providing an increase in overall strength. A 2mm thick brace ties all of the suspension pins together, giving the front and rear suspension assemblies a huge boost in strength. At the point where the pushrods attach to the lower suspension arms, you’re given three mounting points to alter the ride height of your Revo, without altering the progressive action of the suspension.

The 5mm stainless steel pushrods and toe links are fully captured on both sides of the rod ends. This double-sheared approach firmly holds the parts in place, providing a solid hold throughout the suspension. Should you want to lighten your truck up for racing purposes, Traxxas offers aluminum replacements for both of these items as well as other suspension components.

After the introduction of the Revo 2.5, the P2 rockers became an instant hit. They offered a good overall balance for most terrain, making them an instant favorite among the masses. Traxxas took note, and opted to make the P2 rockers standard equipment on the Revo 3.3.

The rockers are specific to each corner of the truck, with an upper and lower half to each of them. Just as throughout the rest of the suspension, the rod ends that connect to the rockers are trapped to increase the strength of the overall assembly. The rockers pivot on a 5mm steel post that is threaded into the bulkhead. At the pivot point, you’ll find a 5x11x4mm bearing pressed into each half of the rocker so that it rotates smoothly as the suspension keeps the tire in contact with the ground. Since the truck is now equipped with the P2 rockers, you’ll also notice that the stainless steel pushrod length has been increased by the use of the red aluminum spacers as well. This keeps the suspension geometry correct for the increased progressive rate of the included rocker set.

Because of the unique shock layout on the Revo, the pushrods provide a great deal of the motion range. This means that the shocks themselves can be shorter than the units traditionally found on monster trucks. There are also other benefits to the inboard shock approach as well. One being that this is what helps provide the progressive action of the suspension, while the obvious fact that the shock is less exposed to possible damage is a huge benefit as well.

The Revo shocks use an aluminum shock body. The upper end of the shock is threaded for the plastic screw-style adjustment ring, which makes adjusting the shock’s preload a simple task. A 3.5mm stainless steel shock shaft provides the proper range of motion, while a rubber bump-stop prevents the shock from bottoming out too harshly on larger jumps.

Inside the shock, you’ll find a piston head secured by a locking nut. At the lower end of the shock body a silicone x-ring provides a proper seal and keeps the oil inside the shock. The shock cap is plastic and features a small hole in it to allow you to easily bleed your shocks. Once you’ve filled the shocks and worked any air out of the fluid, simply screw the cap down about halfway and then compress the shock. Any air and excess fluid will exit via the hole, which means swapping shock oil is as simple as it gets with the
Revo 3.3!

To assist you in removing and tightening the shock cap, the upper end of the shock body has a pair of flat edges on it. You can use the large open-end wrench that Traxxas provides to grip the shock body. The gray shock tool we discussed earlier has ends that will assist you in tightening and loosening the upper shock cap, as well as the lower cap and rod end.

If you want to enhance the performance of your Revo, you’ll be glad to know that Traxxas made accessories for the shocks a priority. They provide a vast number of optional spring sets for you to choose between and allow you to adjust the suspension to suit your conditions. Traxxas also offers other optional shock components that you may want to check out. Both the optional Hard-Anodized Teflon-Coated bodies and Titanium Nitride shock shafts will provide you even smoother suspension action.

The dual steering servo approach provides plenty of steering torque without having to use more expensive servos. If you do prefer to swap to a single servo setup, you can still go that route. To assist you, Traxxas provides a set of aftermarket servo horns for the Revo that makes swapping to other servo brands easy.

The servo horns mounted on the servos use the same double-shear approach found on the suspension components. Since the chassis length is increased at the front, the turnbuckles used to connect the horns to the servo saver are longer than they are with the Revo 2.5. The servo saver uses dual arms to provide points for the linkage from the servos to connect to, and a long 3x30mm screw passes through the skid plate holding the servo saver firmly in place.
The 3x30mm screw actually passes through a steel tube that rests inside a pair of bearings. The innermost bearing is a 5x11x4mm bearing, while the outermost bearing is a little smaller measuring 5x8x2.5mm. The end result is a servo saver that rotates very smoothly throughout its full range of motion. A stainless steel spring protects the servo’s gears, flexing under stress to avoid sending the steering servos too much of an impact. If you choose to upgrade to a servo with a full metal gear drivetrain, Traxxas offers a stiffer spring (part #5344X) for the servo saver that provides a much firmer feel to it.

To power all of the onboard electronics, Traxxas installed a receiver pack as standard equipment. This 1100Mah pack provides plenty of runtime for the truck’s onboard electronics and can be charged in about an hour, thanks to the included Traxxas TRX Power Charger. Should you want to extend your driving time further than what a single pack allows, you can pick up a second receiver pack and easily swap between packs using the lower battery box door. This easily accessible battery box makes swapping receiver packs a simple and quick process.

To make charging the pack that’s installed in the vehicle as easy as possible, Traxxas placed a charging jack at the lower front of the receiver box. The plug for the TRX Power Charger fits directly onto this jack, which is keyed to prevent you from connecting them incorrectly. When the jack isn’t being used, a rubber plug protects it from the elements.

We’ve seen the steering servos, now let’s return our focus to the upper side of the chassis and take a quick look at the rest of the servos that control the Revo 3.3. On the left side of the chassis, in front of the engine, you’ll find a box that holds two servos. The 2055 servo controls the throttle and braking functions, providing 80 oz-in of torque at 6.0 volts. This is the same model of servo that is used to control the steering of the truck, and it provides plenty of clamping force to bring the powerful Revo 3.3 to a quick stop.

While the Traxxas 2055 controls the brakes, it also operates the engine’s carburetor. Another linkage rod extends towards the rear of the truck, connecting to a bellcrank mounted on the aluminum engine mount. A factory installed throttle return spring is also used to make sure the carburetor closes properly when the throttle is released. The bellcrank is slotted to hold the throttle arm on the carburetor, but also makes it easy to pull the engine off of the chassis without the need to disconnect a ball cup end. The bellcrank pivots on plastic bushings, and, just as with the Revo 2.5, you can still drop a pair of 5x8x2.5mm bearings into it to further smooth out the operation of the throttle.

The reversing duties of the Revo are handled by a smaller-sized servo, a Traxxas 2060. Since a high-powered servo really isn’t needed to change the transmission from forward to reverse, Traxxas chose to use smaller and lighter servo. In addition, the smaller servo will use less power than its siblings, extending the runtimes between receiver pack recharges.

When Traxxas went to the drawing board to design the Revo, it seems that making the electronics easy to remove was a priority. Just a few screws are all that’s needed to remove the electronics from the chassis, and most of those screws center around the servos. The nice part is that you can remove the truck’s electronics without altering the servo horns' position on the servos. This eliminates the need to re-center the servos after reinstalling the electronics.

The electronics boxes are mounted onto tabs that make up the sides of the vehicle’s chassis. Once the few screws holding the electronics boxes are removed, the boxes are easily separated from the rest of the truck. Double-shear connections can be separated to remove the servo linkages from the steering or braking assemblies. It’s a very efficient and well planned arrangement.

The lid on the receiver and servo boxes are easily opened and removed, since they are each held in place by a single body clip. The receiver box lid has an opening in it that allows you to see the OptiDrive unit mounted inside the box. This makes checking the status, or resetting the unit, easy. Closer to the front of the receiver box, you’ll find a power switch that allows you to switch the onboard electronics on and off as needed.

Inside the receiver box you’ll find a myriad of wiring, as the OptiDrive and dual servos necessitate a few more wires than you might usually see. However, it’s really not very complicated if you take the time to follow each wire, and Traxxas makes it easier by color coding the OptiDrive plugs. The receiver box has plenty of room and should easily accommodate any popular aftermarket receiver, should you decide to switch to a different radio later. Underneath the receiver mount, is the afore mentioned battery compartment.

The Traxxas EZ-Start consists of two core components. The handheld starter was seen earlier. The other major component is the on-board EZ-Start assembly, which is mounted directly to the engine. The on-board EZ-Start is what actually turns over the engine during the starting process. The wires for the EZ-Start motor are routed between the rear shocks, where a plug can be found on the rear shock tower. We’ll cover the EZ-Start assembly and the engine again a little later.

The Revo’s transmission is a very well designed unit. While you have to get inside the transmission to recognize some of the details that went into it, examining how easily the transmission is removed is a start. Only four screws are used to hold the transmission securely onto the chassis. These screws pass through the transmission’s skid plate and are easily removed when needed. The whole transmission can be removed from the truck in a matter of a minute or two.

That should be old news for those who have been running the Revo 2.5, though. However, once the transmission is opened up, Revo veterans will be thrown a curve ball. The Revo 3.3’s transmission comes with the wide ratio gearset installed. This gearset utilizes the increased powerband offered by the TRX 3.3, although the wider gearing range may not be optimal for smaller tracks. Just as before, though, the internal gearset can be easily swapped between the close, standard, and wide ratio gearsets. The installed wide ratio gearset combined with the new TRX 3.3 powerplant is what pushes the Revo to top speeds over 45mph.

The transmission sports a full set of ball bearings throughout, and the large teeth on the internal plastic gears provide a great deal of strength while keeping rotating mass low. The rear half of the transmission houses the main drive gears, including the wide ratio gearset and the two-speed assembly. The front of the transmission has the task of housing the reversing components and gears. Should you install the optional forward-only conversion or center differential, these will be the components you’ll end up removing from the transmission.

I mentioned the two-speed assembly a moment ago, and many Traxxas veterans should be familiar with this item. While the part differs slightly from the one used on the T-Maxx, the pawl-style shifting mechanisms are very similar. A single 2mm grub screw is used to adjust the tension on a spring that controls the exact shifting point. This allows you to further tailor the performance of the truck, in addition to the gearing options that are available. A hole is provided in the transmission housing, allowing you to quickly and easily adjust the shift point without the need to remove the transmission from the truck.

At the rear of the transmission, you’ll find the metric-pitch spur gear. The stock gear has 38-teeth and mates with the stock 15-tooth clutch bell. The spur gear mounts onto a slipper clutch assembly that uses pads instead of friction pegs. The semi-metallic slipper pad setup used on the Revo provides you with an increased control over the friction setting, although the method used to set the slipper differs from peg-based setups. The Revo’s slipper should never be over tightened, as indicated by the warning sticker affixed to the transmission.

The slipper setup found on the Revo offers one other substantial benefit. The spur gear can be removed without altering the slipper clutch setting. The slipper clutch is an item that is often overlooked in its importance, but Traxxas has ensured that the Revo’s slipper clutch is as advanced as the rest of the truck.

A truck as advanced as the Revo needs a top quality braking system to slow it down as quickly as it can accelerate. With that in mind, Traxxas made sure it didn’t disappoint. First and foremost is the braking linkage. Without the linkage, there would be nothing to activate the braking assembly. The linkage is connected to the transmission with a hex-head screw, making it easy to separate it from the transmission if the need arises. A plastic knob threads onto the linkage rod, allowing you to easily alter the braking tensions to account for traction conditions or brake pad wear.

The brakes use a pair of semi-metallic slipper pads to clamp down on a stainless steel cross-drilled brake disk. This setup provides a vast amount of clamping force without demonstrating any noticeable brake fade. Speaking from my previous experiences with this setup, you can easily dial-in enough braking force to flip the Revo up on its front wheels if you aren’t careful. The Revo has plenty of stopping power. On top of that, the transmission housing has slight changes to accommodate the optional Traxxas Rear Brake kit (part #5417), as well, which should be used in conjunction with the optional Traxxas Center Differential. I’ll cover these items in more detail during part two of this review.

Up at the front of the transmission, you’ll find the OptiDrive’s sensor. The wire’s plug is color coded to indicate the correct slot it should be plugged into on the OptiDrive unit. The sensor monitors a gear with a set of teeth around its circumference. If it senses the gear is moving, it knows that the vehicle is in motion, and therefore prevents the vehicle from being shifted into reverse. You can see this is working on the OptiDrive unit, as the blue light will be blinking as the transmission’s gears are spinning.

With the electronic OptiDrive system installed on the Revo 3.3, Traxxas eliminated the need for a clutch-based reverse. The result is a smooth delivery of power and very little rotating mass associated with reverse inside the transmission.

While the OptiDrive has the primary purpose of preventing you from accidentally shifting the truck into forward or reverse while moving in the opposite direction, it provides a few other benefits as well. When you run the truck in reverse, it limits the amount of power sent from the engine to the transmission. This prevents unnecessary wear and tear on the transmission, helping you to maintain control while backing the vehicle up. It also provides several failsafe-like functions. If battery voltage drops to an unsafe level, the OptiDrive will return the engine to an idle state and apply the brakes to prevent a runaway scenario. The same will happen if there is frequency interference or if the signal from the radio is no longer present..

The actual shifting action is handled by a Traxxas 2060 mini-sized servo. This servo moves a linkage rod that connects to a spring-loaded lever. The far end of this lever connects to the shifting fork that exits the front of the transmission, and moves the fork in or out of the transmission as necessary.

One of the goals when the Revo was designed was to allow easy access to the differentials. Since the Revo features sealed differential units that are meant to be used with differential oil, easy access is important for tuning purposes. For this reason, Traxxas designed the whole front and rear bulkhead assemblies with the ability to be separated from the rest of the truck. Once the assembly is removed, the axles can be detached from the differential, and the differential can be lifted out of the top of the assembly. From that point, you can easily change the diff oil weight to suit your driving style or conditions.

The differential housing is split into front and rear halves, which are held together by hex head hardware just like the rest of the truck. To avoid the differentials from being installed incorrectly, the case is marked with an indication of which end should be facing up once it’s installed.

The ring and pinion gears are straight cut and ride on a full set of ball bearings. The pinion gear’s shaft passes through a pair of 6x12x4mm bearings, while the differential spins inside two bearings that are slightly different sizes. The side of the differential with the ring gear uses an 8x16x5mm bearing, while the opposite side uses a 10x15x4mm bearing. The end result is a differential that spins very smoothly with virtually no rolling resistance. Hardened steel hex-head hardware holds the ring gear solidly against the differential cup.

Inside the differential you’ll find a four-gear setup that’s very capable of handling the power sent through the Revo’s drivetrain. A rubber seal is used between the ring gear and differential cup to seal the unit, while silicone x-rings are used to seal the differential’s output shafts.

Earlier I mentioned the larger axles and the multi-spline approach used by Traxxas. The driveshafts get this treatment as well. The result is a strong plastic slider solution that rivals CVD style assemblies. E-clips hold the universal joint together, and when they are removed the joint is easily disassembled. With the 2.5R version of the Revo, the front driveshaft was shorter than the rear; however, the Revo 3.3 sports the same length driveshaft at both the front and the rear of the truck.

While the rolling rubber is still the same, the Revo 3.3 uses a different set of wheels than the 2.5R version does. This time around the Talon tires are pre-glued onto a set of Split-Spoke mirror-chrome wheels. The wheels still use the lipped mounting channel that was found on the Revo nearly two years ago, and they definitely provide a very positive and solid hold on the tire. The offset of the different wheels is the same, and the Talon tires will suit most bashers perfectly, offering a good balance of wear and traction. Racers will probably decide to upgrade to a tire that suits their track the best. One good option for racers is the Traxxas Response tires (part #5471), which are sold separately.

Now we come to the heart of the Revo 3.3, and the part many potential owners will likely be the most interested in. That is the 3.3cc, .20 cubic inch, powerplant. Traxxas customers have been asking for more power. With the TRX 3.3, Traxxas provides exactly what its customers have been seeking, and all this in an engine that will drop into the same spot the as the TRX 2.5. This makes it the largest drop-in replacement engine available for the Revo, while still using all of the factory hardware.

The Traxxas TRX 3.3 engine uses an oversized aluminum head that is finished in blue-anodizing just like the TRX 2.5R. Super large cutouts in the sides allow you to easily reach the screws that secure the engine to the engine mount. This engine head also uses a protective plastic ring just as the TRX 2.5 does, although a set of five screws lock the ring onto the head so it doesn’t pop off while driving, jumping, or crashing!

The overall construction of the engine is very similar to the TRX 2.5, so, if you’ve had any experience with the main powerplant offered by Traxxas, you’ll be in familiar territory. But, make no mistake. The engine is bigger. To distinguish it from the TRX 2.5, Traxxas has emblazoned TRX 3.3 on the side of the block, right alongside the engine block’s cooling fins.

One of the nicest features of the new TRX 3.3 engine is that it maintains compatibility with the EZ-Start electric starting system. This means that the pullstart from the TRX 2.5 will fit, as well, should you decide to go that route. The EZ-Start system is one of the best options available for beginners in the nitro genre. Not only does it provide an easy way to start your Traxxas truck, but it can also diagnose common starting problems. This is a big benefit for novices, and even some lazy veterans!

The TRX 3.3 makes use of the composite carburetor that was first used on the TRX 2.5. This carburetor provides several benefits over standard aluminum carburetors, especially in the fact that it avoids heat affecting the incoming fuel. When incoming air and fuel is not heated by the carburetor, it provides a much more precise mixture throughout the engine’s temperature range. The composite Traxxas carburetor allows for a very fine range of adjustments. While this provides for precise control over the fuel and air mixture, it’s often a struggling point for some hobbyists. Therefore, I should point out that all adjustments made should be small. I’d recommend using no more than 1/12 of a turn at a time when leaning the engine. Then run the truck to allow the new tune to settle itself before attempting to make further adjustments.

The various internal components of the TRX 3.3 should look very familiar to anyone who has taken apart their TRX 2.5. They’re just sized larger for the .20 ci mill. I am glad to see this, as the TRX 2.5 was simply a groundbreaking engine when it was released, and it is still one of the best small block engines on the market. For them to base the TRX 3.3 upon this, shows how well designed the TRX 2.5 was to begin with. All of the parts are precision-made, and the piston and sleeve feature true ABC construction for long life and excellent power characteristics.

I’ll admit that I was a little curious as to how the sizes of the TRX 2.5 and TRX 3.3’s piston and sleeves would compare. So, I dug through my various RC bins until I came across an engine I’d torn down and had never reassembled. Then I threw them side by side for a quick comparison. The bigger TRX 3.3 engine parts I placed on the left of the TRX 2.5 parts were much larger indeed, making the extra displacement very easy to see. I then placed the TRX 2.5 piston inside of the sleeve of the TRX 3.3, making the size difference between the two engines even more obvious!

One final note about the new TRX 3.3 powerplant is that it maintains mounting compatibility with all of the TRX 2.5 header and pipe combos you may have come to love. While you should take care to choose a pipe that suits your needs, it’s nice to know that a healthy selection exists for the engine upon its introduction. Given that the engine comes equipped with the same pipe and header used by the TRX 2.5, I’d imagine the right choice might help the engine breathe a little easier and provide you any extra power boost you may desire. If you’re looking for a replacement pipe, the Resonator pipes offered by Traxxas are definitely a good place to start.

There are a few items you’ll need to complete before you fire your truck up for the first time. First, watch the DVD, and read through the manual. Don’t make the mistake of thinking the DVD is a substitute for the manual, either, as the manual covers the truck much more completely than the DVD. The DVD is merely an accompaniment to the manual. The better you understand your truck and the details that keep it running, the better your overall experience will be.

The first item I tackled on the Revo 3.3 was the receiver antenna. I ran the antenna wire through my fingers to straighten it out, and then threaded it through the supplied tube. If you find this difficult, sprinkle a little baby powder on the antenna wire, it’ll help tremendously. Then I pushed the tube into its resting place on the receiver box.

I also used the supplied antenna cap to protect the antenna wire where it passes out the top of the tube. Traxxas also supplies you with a small open end tubing section as well. This helps to keep the excess wire from dangling loose. You could also use a small section of spare fuel line.

The onboard electronics will need a source of power, and the Revo comes factory-equipped with an 1100Mah receiver pack. The charging plug found on the bottom front of the receiver box makes the charging process very easy. You simply plug the Traxxas TRX Power Charger directly into the plug on the underside of the truck, and you’ll have a fully charged receiver pack in about an hour. If you pick up a spare receiver pack, you can use the TRX Power Charger to charge it outside of the truck as well.

A few other battery-related items need to be addressed in addition to the receiver pack. The first of these is the radio. It takes a total of eight AA batteries, and I recommend you use a set of fresh cells. They’ll last longer, and give you a much better range of operation. You’ll also need a standard 6-cell flat pack with a standard connector. Remember that the Traxxas TRX Power Charger will not only charge a 5-cell receiver pack, but it will also charge a 7.2V 6-cell EZ-Start battery pack. The manual covers the information regarding charging the different Mah capacities, and how to use the charger with them.

Depending upon the climate, you may want to cut a hole in the windshield of the truck to help provide airflow to the engine. I’ve found that I get the best results by using a body hole reamer to make a pilot hole. Then I follow up with a pair of curved lexan scissors to make a nice round circle. Last of all, you should pay close attention when you install the body onto the Revo. While there is ample room between the engine head and the body, ensure that the wire isn’t caught between them. Also make sure that the starter wire is tucked into place under the head protector, as this provides the most protection to the wire should the truck roll over.

The time had arrived for me to fire up my Revo 3.3 and run it for the first time. Despite the fact that I had performed the Traxxas break-in procedure numerous times, I still read through it one more time to refresh my memory. Then I set off to the local high school parking lot.

The ambient temperature was mid 70’s, and the sun was shining brightly as I prepared the Revo for its maiden run. Prior to leaving the house I charged up a 6-cell battery pack, as well as the receiver pack, and installed fresh AA batteries in the TQ-3 radio. I was ready for some action.

I fueled the truck up with 33% Top Fuel, and then switched on the radio and receiver. Then, using the EZ-Start, I attempted to fire the Traxxas 3.3, and a few seconds later was greeted with a raspy roar of a two-stroke nitro idling a little richly. I applied the throttle and started to run the truck down the parking lot, as instructed, for the first tank of the break-in process.

About and hour and fifteen minutes later, the break-in process was complete and the Revo 3.3 was ready to hit the local track. During the process, it was easy to tell how powerful the engine was going to be. However, I knew that the process shouldn’t be rushed and that I should follow the break-in process to the letter. It’s hard to do, though, when every thought in your mind seems destined around nailing the throttle to see exactly what the truck has to offer. Good things come to those that wait, and I knew that having a well broken-in engine at the track was much more important than rushing the break-in process.

After breaking-in the Revo, I immediately headed to my home track, Monkey Bottom Raceway. The large layout, and jumps, put the truck to the test. The long and wide front straightaway would also give the wide-ratio gearset of the truck a little room to stretch its legs. While I wouldn’t have any timing equipment on hand for the practice session, I did have good knowledge of the track. Typical good lap times are in the 41-42 second range, and every now and then I’ve managed to turn in some times under the 40 second mark, although not as consistently as I’d like.

I pulled out all of my equipment and soon had the truck running again. I had the track to myself, so I took a few laps and then tuned for on-track performance. Next, I ran through several tanks until the engine truly came to life, which was around the tenth tank. The conditions were dry and dusty, much more so than I’d normally experience under race day conditions. I was curious how well I could push the Revo 3.3 around the track in its "straight out of the box" configuration. I didn’t even touch the preload settings, but took it straight from the box, to break-in, and then to the track. This is the setup I used throughout my testing, and what is captured throughout the video and pictures. My only exception to this rule was to alter the transmission’s shift point later on in the session.

I spent my first few tanks getting used to the feel of a stock Revo again. It had been quite some time since I had driven a 100% stock truck, and I was surprised at how well it handled in this form. The feeling was very plush, and the truck leaned considerably in the corners. This helped keep the stock Talon tires stuck to the ground, even in the dry conditions. The Revo 3.3 did an excellent job of planting the tires in the corners.

Soon, after finishing up a few tanks, the engine seemed to be loosened-up and operating at its full potential. I started pushing it around the track a little faster with each pass. Even with the increased speeds, the stock Talon tires performed well. I could tell that they were being pushed to their limits, but they continued to impress me with their ability to stick to the track.

After racing around the track several times, I pulled the truck back in and made a quick change to the shifting mechanism. Even on the fairly long straightaway, the shifting occurred a little too late. I wanted to hit second about a third of the way down the front stretch and give second gear a little more time to wind out. I backed off of the shifting adjustment about an 1/8 of a turn. Once back out on the track, this one small change suited the truck much better. My speeds down the straightaway picked up considerably with the truck getting close to the 45mph range before I had to back off the throttle.

After making the shifting change, the turn at the end of the straightaway was the only turn with which the stock tires seemed to encounter any major difficulty. It was easy to carry too much speed into the corner and feel as if I were at the edge of control. This made it tough to reliably clear the double, as I am normally used to at the track. If I managed to hang on through the corner, I could successfully pull off the double. However, more often than not, I didn’t feel as if I had proper control of the truck as I hit the first jump and merely singled over both of them.

Singling the jumps wasn’t such a bad route, though, as it has proven itself to be a very conservative route to take. Even when racing, I have been know to single the jumps when I simply want to turn a consistent lap and avoid making a mistake, giving up a nice lead. The Revo 3.3 made this even easier, as the raw power from the .20 inch engine could reach deep down and provide plenty of low end grunt between the jumps, resulting in very little time lost.

One of my favorite sections of the track was recently built over the off-season. This section replaced a tabletop alongside the front stretch, which had previously stood as my favorite section of the track. This new section features a large triple, which is a great deal of fun for the buggy guys, while still being spaced out well for the monster truck crowd.

My normal approach for this section is to double the first two jumps, and then single the last one. I start off by hitting the opening jump around ? throttle, as this puts me in a perfect position to bring the front end down and run down the backside of the second jump keeping my speed up throughout the section. Then I quickly pop over the second jump and head around the right-hand turn to the rest of the track.

The Revo 3.3 was really suited for my driving style through this section of the track. The longer chassis seems to like to nose-down slightly by default, since I wasn’t hitting the jump wide open, which made it really easy to setup for a run down the backside. When that was combined with the better feel and control I had in the turn leading up to the jump, I felt more comfortable through this section of the track than I ever had before. The extended chassis just changed the dynamics of this section of the track completely from what I was used to, and this was on the stock tires!

The longer wheelbase also helped me throughout the rhythm section of the track. It kept the truck much more composed as the wheels cut through the small bumps leading up to the last tabletop on the track. Then, as I cut through the turn and headed up the jump before the tabletop, I could carry plenty of speed which allowed me to land on top of the tabletop and then run down the backside.

Throughout the other sections of the track the Revo 3.3 performed just as well and was just as stable. I felt as if I were in excellent control as I rounded the corners and hit the other jumps throughout the track. I was in awe at how well the truck handled the track in its box-stock form. I spent the entire afternoon running the truck in this configuration. My next outing brought me back to the track again, with the truck in a modified form using the optional center differential and rear brake kit. However, this first outing had me pleased from the moment I first started the truck and pulled out onto the track.

Revo fans are definitely not going to be disappointed with the release of the Revo 3.3. Obviously, the biggest change is the new .20 cubic inch powerplant, but there’s much more here than simply an engine change. The extended chassis makes a world of difference in the stability of the truck, and the transmission and chassis are fully compatible with the optional rear brake kit. Then with items such as the included engine brace, wide-ratio transmission gears, and P2 rockers, there’s a little something here to make everyone happy!

The Revo has definitely been the dominant monster truck at the track, in the production and small block classes. With the new changes, it’ll be pushed that much further ahead of the competition, and increase the ability of the truck to be pushed even faster around off-road tracks throughout the country and the world. All other trucks should stand up and take notice. The bar was set high before, but Traxxas has inched it upwards and the monster truck scene will once again never be the same!