Review: MCD Race Runner V4

The world of large-scale racing took a giant leap forward when the HPI Baja hit the scene. It was fun, fast, durable and able to run almost an hour on a tank of 2-stroke fuel! When track owners took notice, dedicated 1/5th scale tracks began popping up around the country complete with wide lanes, sweeping corners and huge jumps. Large-scale was here and in a big way.

During this time, MCD has released a few of their large-scale 4wd vehicles, however none have really penetrated the US market. That is, until the Race Runner V4 appeared. MCD has combined 1/8th scale looks with an excellent suspension and drivetrain to create what appears to be the next generation of big-scale offroad. In my opinion, it was only a matter of time.

THE FACTS
WHO MAKES IT MCD
WHO IT’S FOR Intermediate to Advanced Racer
HOW FAST 42mph
HOW MUCH $1299
BUILD TYPE RTR
VEHICLE TYPE 1/5-Scale Gas Buggy

WHAT YOU NEED TO KNOW
– You can purchase the RRV4 from Large Scale RC as either a roller or a full RRR (Race-Ready Ride). If you purchase it as a RRR, the boys at Large Scale will do all the grunt work for you, letting you pull it from the box and go! If you decide on the roller, there are a ton of different directions you can go to create a very unique version.

– The MCD RRV4 includes a front and rear fluid-filled differential. These can be tuned by adding different weight fluids. The center differential is actually a solid-drive gear. To help squeeze every ounce of performance from the Race Runner, MCD offers an optional center fluid-filled differential.

– Transferring all this power to the wheels requires some stout drive axles, so MCD has included a set of their thick 7mm CVD’s up front. An equally impressive set of 7mm dogbones drive the rear wheels.

– The steering system on the MCD is unique in that you can use one or two servos. The steering setup has two steering arms, each equipped with a heavy duty servo saver. Each can be individually adjusted and include a heavy duty servo saver spring.

– To protect all the internals, a heavy duty aluminum roll cage runs from each differential case to a chassis-mounted ‘hoop’ just behind the engine. This cage not only helps protect your expensive investment (most likely the engine), it also helps reduce front-to-rear chassis flex.

– The body and wing give the Race Runner a very racey look. The body sits nice and tight to the chassis and keeps out quite a bit of goobers that could crud up the driveline. Scoops on each side can be cut out to help with airflow, as can the front and side windows. The adjustable rear wing is a big ol’ hunk of thick plastic, but is high enough over the top of the body to actually make it functional.

– When choosing a pipe, do some research as there is not a whole lot of room under the bodywork.

DESIGN ANALYSIS
• The engine is mounted in the center of the chassis for perfect side-to-side balance. While you’d think this would block any rear drive axle, the engine is mounted just high enough for the rear driveshaft to pass under it.

• This brings us to the next interesting feature; the fuel tank. To compensate for the centrally located engine, a large fuel tank extends the width of the chassis. The rear driveshaft runs through a hole molded into the tank, allowing rear drive.

• The gear reduction unit (or, I guess, a sort of transmission) is mounted to the right side of the engine. Remove the cover and you will see the clock-like gears. Swap these out to change your gear ratio.

• The block tires are mounted to a set of rigid plastic wheels. MCD has engineered the RRV4 to use the same size wheel hex as the HPI Baja; however, the overall height of the MCD tire is closer to the overall height of the 5T than the 5B. But this still gives you some additional tire options.

• The radio tray mounts in front of the engine and gives you the option of using one or two steering servos. The throttle/brake servo is mounted just behind the steering servos. MCD also gives you the option to run large-scale or 1/10-scale servos. A sealed receiver box is located to the left of the chassis.

• Holy plastic Batman! Yes, the MCD is almost entirely plastic, but it’s some BEEFY plastic! Ridges, ribs and standoffs abound, but it all interlocks into a pretty rigid platform. There are only a few aluminum braces in the key areas for maximum strength

ITEMS NEEDED
– 6V receiver pack
– Engine
– Servos (2 or 3)
– Exhaust Pipe
– 2 Channel radio system
– Battery charger
– Fuel

ITEMS USED
+ HPI Hump Battery Pack
+ Bartolone Racing Modified 30cc Engine
+ Hitec 5755MG (x2–Steering), Hitec 5745MG (Throttle)
+ GBE Custom MCD End-Bleed Pipe
+ Outerwears Air Filter Cover
+ Airtronics M11x
+ LRP Pulsar Competition 3
+ 91 Octane with Motul 2-Stroke Oil

TOOLS INCLUDED
+ Wheel wrench

TOOLS NEEDED
– Screwdriver (Philips)

SPECS &TUNING OPTIONS
MCD Race Runner V4
DIMENSIONS
LENGTH: 32.2 in. (817.8mm)
WIDTH: 18 in. (457.2mm)
WHEELBASE: 9.25 in. (234.9mm)

SUSPENSION
• Shock position—3 holes on towers, 4 on suspension arms
• Caster—inner tower clips
• Camber (F&R)—spacers behind the mounting rod
• Droop—screws in the arms
• Roll—multiple camber rod locations front and rear
• Ackerman—2 positions
• Toe— front turnbuckles
• Wheelbase—rear hubs can be spaced

DRIVETRAIN
• Diff stiffness—grease or silicone diff fluids

MAINTENANCE AND TUNING TIPS
• After initial testing, I noticed the side-exit pipe was very close to the fuel tank and body. As a precaution I lined the underside of the body with heat-resistant tape, as well as the corner of the tank.

• To keep the MCD running in tip-top shape, I would suggest checking the air filter after every run to make sure it’s not gunked up. Outerwears sells a filter cover that does a fantastic job of keeping the filter clean.

• After each run it’s not a bad idea to check the screws to make sure none of them have vibrated out of position. In fact, a little dab of thread-locking compound will help keep them in place.

• CHECK YOUR RECEIVER PACK! Make sure you keep it charged or you’ll end up with a 25lb paperweight!

PERFORMANCE
Test Conditions: Semi-smooth dry track

STEERING Neutral
I thought for sure that, because of its size and weight, the RRV4 would push like a dump truck around the track. I was surprised when I found that it could carve a corner like a slot car. Of course, strapping in two beastly Hitec 5755MG servos certainly helped! I could put the Race Runner anywhere on the track I wanted and it turned in well, constantly swooping in on other unsuspecting 1/5-scale cars.

ACCELERATION Excellent
Big power and 4WD always equate to excellent acceleration, and the MCD didn’t disappoint. From a standstill, it was awesome to see all four tires throwing a huge roost. Out of the corners, it was unmatched by anything else on the track. Mating the Bartolone Modified 30cc Race Engine to GBE’s custom pipe (production pipe coming soon) provided enough power to easily challenge a cheetah.

BRAKING Good
The MCD’s dual-disc braking system worked great, slowing the RR down with ease. When I pushed the MCD to its limits, I did notice some brake fade, probably caused by the fact that the braking system is so close to the engine. Keep your pace fast and steady and you shouldn’t have any issues with slowing down.

SUSPENSION Excellent
Watching the RRV4 traverse the track was like watching a 1/8-scale buggy… it doesn’t necessarily look really fast around the track, it just is! The stock suspension soaked up every bump and dip the track had to offer. Tap the brakes going into a corner and the rear end would break loose… grab some throttle and you were well on your way down the straight. The short wheelbase did buck the RR a little in the washboard section, but that’s an acceptable ‘problem’ when it’s so good everywhere else.

JUMPING Excellent
Jumping is usually my favorite part of testing, as it shows the vehicles ability to jump, land and any type of control issues in the air. Luckily for me, the test track had a fast sweeper into a huge tabletop jump on the back straight. On a good run, most 1/5-scalers were landing just over the crest of the tabletop. The MCD, however, wanted to make a statement. With the massive Bartolone power and 4WD, I sent the RRV4 flying over the tabletop, easily landing five feet past the bottom of the landing! This got the attention of everyone in the pits so, of course, it was time to show off. Launching off the face of the jump, the MCD did display a bit of a nose-up attitude but, as with most 4WD vehicles, I was able to bring the nose down by hitting the brakes. This gives the MCD a huge advantage over the 2WD buggies.

DURABILITY Excellent
You’d think that with a ton of horsepower, 4WD and big jumps; this would be the recipe for disaster. I’m happy to say that other than a front bumper tweaking out of position I had a very uneventful day in the durability department. The drivetrain held up great, and the gearbox cover did its job by keeping all the rocks and debris out of the side gears. Shocks were still smooth and the suspension arms continued to have free movement. The wing standoffs were a surprise; I thought for sure they’d break right away after the first crash. Even the stock tires held up to my punishing, full-throttle track-attack.

PROS & CONS
+ Beefy 4WD drivetrain can handle a TON of power
+ Accepts dual servos for excellent steering
+ Lots of tuning options
+ Centralized fuel tank helps weight distribution
+ Enclosed gears keep dirt out of drivetrain
+ Stock tires actually hook up rather well

– Have to take the body all the way off to refuel
– Some engines need to be modified to clear the driveshaft

THE LAST WORD
The MCD Race Runner V4 is by far one of the best 4WD 1/5-scale vehicles out there. It’s fast, durable, handles great, jumps even better and, if you’re a current large-scale junkie looking for something new, will accept most of your current 1/5-scale running gear (except maybe your pipe). In stock form it will keep up with any big-scale vehicle on the track; tweak the suspension a bit and you should be able to leave them behind.

LINKS
MCD, distributed by Large Scale RC, www.largescalerc.com, (219) 253-8356
Hitec, www.hitecrcd.com, (858) 748-6948
HPI, www.hpiracing.com, (949) 753-1099
LRP, distributed by Team Associated, www.teamassociated.com, (949) 544-7500
Bartolone Racing, bartoloneracing@yahoo.com (714) 767-7223
GBE, www.gberacing.com, info@gberacing.com
Outerwears, www.outerwears.com, (800) 967-3450
Airtronics, www.airtronics.net
Flying Blind Design, www.flyingblinddesign.com