RACE READY – We Drive the Reigning 4WD World Champion Team Associated B74.2D

Team Associated is no stranger to winning world championships, with an unmatched 32 titles under its belt. This tradition continued this past summer with factory pilot Davide Ongaro at the wheel, piloting Associated’s latest version of their 1/10-scale 4WD, the B74.2D. Since its introduction several years ago, the B74 has gone through changes, upgrades and enhancements to culminate in the current world champion iteration. The B74.2D focuses on light weight and tuneability with lighter gearboxes, all-new 13mm shocks, gullwing-style front arms, and with a lot more features under the hood. Let’s take a closer look at what makes a world championship-winning buggy.   

Performance Oriented Chassis
Constructed of a 2mm-thick 7075 aluminum plate, the B74.2D’s chassis is built for performance as well as convenience. Bolted down the center of the chassis are two plastic chassis braces that are reinforced with top plates where you can run all screws on top and bottom, or play around with omitting some screws to experiment with torsional chassis flex.

The battery bay is now using a rubber O-ring style strap to hold the battery in. Plastic inserts are included to allow you to move the battery fore or aft and change the weight bias. A plastic tray is used where the speed control mounts and is bolted down the centerline of the chassis. This minimizes binding to the chassis flex as well as making it easy to remove the ESC when doing general maintenance.

Adjustable Drivetrain
At first glance, the B74.2D’s drivetrain seems like a normal affair like all other buggies, but it’s the attention to detail that counts. While the three fluid-filled differentials use steel gears and outdrives, material is kept to a minimum to keep everything lightweight for lower rotating mass. They are housed in all-new lightweight molded gearboxes front and rear.

While the front uses two different included gearboxes to change the diff heights, the rear uses outdrive inserts that change the height of the diff to suit running on dirt with higher ride heights or carpet with lower ride heights. The center diff gets mounted onto aluminum bulkheads (which are normally aftermarket options), with one doubling as a motor mount.

It also has a bolt-on spur gear design that allows you to change between the included 72- or 78-tooth spur gears without having to take apart the whole differential. CVA driveshafts are used throughout with a new 66mm-length rear set included to promote smoother power delivery and stability.

NEW 13mm BIG-BORE ALUMINUM THREADED SHOCKS
Shocks are the heart of a suspension, and the B74.2D got a new set to take on the world. The shock bodies are beautifully machined aluminum pieces that are threaded to allow quick ride height changes via turning the blue aluminum spring collar. Housed inside are machined and precisely shaped shock pistons that are mated to titanium nitride coated 3mm shock shafts for buttery smooth action against the X-wing type O-rings.

Up front you’ll find new gullwing type suspension arms with matching shock tower designed to lower the center gravity and minimize any unwanted chassis roll. To increase durability and lower the chance of breakage, updated 3.5mm turnbuckles are used on the upper camber links and steering linkages.

TEST GEAR
Not only does Team Associated produce world-class cars, but world-class electronics too with their in-house brand, Reedy. This made it easy picking gear without having to shop the vast amounts of RC gear out there. Of course, a world champion car deserves top-shelf electronics, and I started with Reedy’s Blackbox 610R speed controller. With motor and battery wires already installed, it made cutting wires to length and soldering them a breeze.

The 13.5 4WD buggy class is one of the hottest classes around, and a motor with monster horsepower and torque is a must to be successful. For the motor, I dropped in Reedy’s newest SP5 13.5, which has already been proven to be a force in this highly contested stock class.
These motors of course are hungry for some wattage, and Reedy has an answer for this with their Zappers line of LiPo batteries. I chose the Zappers 4800mAh 90C 7.6 LiPo shorty battery. All during testing, this feisty battery showed excellent numbers on my iCharger with internal resistance numbers in the 1.3s to 1.4s, and it definitely manifested on the track with crisp acceleration and more than enough torque to clear any jump on the track.

Steering duties were handled by a Reedy RT200A low-profile titanium gear servo. Although this servo is labeled Hi-Torque it’s no slouch on speed, outputting a transit time of 0.085 seconds at 7.4 volts, giving instant response in the most demanding sections of the track that require fast steering action in tight, instant switchbacks.

Tires are 80 percent of a car’s handling and I used JConcepts throughout all my testing. For outdoor dirt I used Double Dees and for indoor clay I used pre-mounted Smoothie slicks.

BEHIND THE WHEEL
When it came down to testing, Southern California has many tracks within an hour’s drive of me. Close by are The Dirt Raceway 1/10-scale outdoor track in Perris, California, and the SDRC Raceway indoor clay track in Miramar. I could feel the box-stock setup was on the soft side and was probably designed to make the car easy to drive. A good match for this, I felt, would be an outdoor, loose-dirt environment with medium to low grip.

It was a slow practice day at The Dirt Raceway, and with the track freshly groomed by none other than Joey “Dirt” Christensen himself I was ready to put the B74.2D through its paces. For testing on outdoor dirt, I chose JConcepts blue compound Double Dees, and with all batteries fully charged I went out for a shakedown run.

Right off the bat I noticed the powerful Reedy 13.5-turn motor had way too much punch coming on power out of corners, which was easily corrected by turning down the torque halfway on the Reedy Blackbox 610 speed controller using a ESC Tuner Box.

With that done, power delivery was a lot smoother and allowed the tires to bite and get max traction. With the stock setup and running with a 20mm ride height, the suspension action was silky smooth in the bumpier sections of the track, inspiring confidence at the wheel and prompting me to push harder. After running a few batteries and familiarizing myself with the handling characteristics of the buggy and the track layout, the B74.2D was easily up to pace with other 13.5 4WD buggies also practicing that day.

RACE DAY SETUP
Overall, it took very little effort to make the B74.2D competitive. I carried this forward momentum to SDRC Raceway to do some indoor clay track testing. Wednesdays are their race nights and I arrived right when the track opened at 2 p.m. With five hours until racing started, I strapped on some silver compound JConcepts Smoothies slicks. With the box-stock setup still on the car, I charged up the battery, sauced the tires and hit the track.

Having already had a handful of race days on the current layout running both the Expert 17.5 2WD Buggy and 4WD 13.5 Buggy classes, I had a direct reference for comparison. It only took a few laps for the tires to break in. With the track already being higher grip, the B74.2D had a ton of traction, and although the performance was good, the soft setup made handling too sluggish in all corners.

Stiffening up the overall setup was the plan and I started by swapping out the included front Yellow 4.3-lb springs and rear Blue 2.2-lb springs in favor of Yellow 2.3-lb rear springs and Red 4.6-lb front springs.

I left the stock shock pistons in place and 30wt oil in the rear, but went to thicker 40wt oil in the front to match the stiffer spring. It produced an immediately noticeable change on the track as the suspension woke up on the grippy surface. With almost on-road car-like handling, the B74.2D made short work of almost every corner on the track, and jumping performance was exceptional, getting airborne perfectly level and making it easy to point the nose up or down with throttle and brake inputs.

Landings were plush, even with the 16mm ride height I had set, and without any hint of bottoming out. Getting on the power was immediate and I remained in total control after landing. After a handful of runs I managed to shave a couple seconds off my lap times—but in true racer fashion, I wanted to go faster.

After a quick walk around the pits I found Associated fast guy Matthew Gonzales, and after some quick notes I had some homework: changing suspension pills, diff oils and roll center positions. The changes I ended up making were moving inner camber link positions in the rear to the innermost holes and all the way down, and the front to the inner holes and all the way up. On the front link I also swapped the stock 2mm outside washer to a 1mm washer. The only change I made on diff oils was going thicker in the front from 10K weight to 15K.

For the hinge pin pill swap, in the A-block I fitted 1mm upper/inner pill with the B-block getting 1mm lower/inner. In the C-block I put in the 0.5 upper/inner pill, and on the D-block I stayed with the stock center pill. On the track the changes were positively in the right direction, adding extra stability and, more importantly, what I was looking for: mid-turn cornering speed that allowed me to get down into the lower 17-second lap times.

READY TO RACE
So how did racing go? Qualifying was super-clean with near crash-less runs that scored me 4th position on the A-Main grid. The Main saw some more of the same. Some crashes happened in front of me early in the race, and avoiding them put me in the lead and I never looked back. The B74.2D performed perfectly and allowed me to put it exactly where I wanted it. In the end I was able to open up an 8-second lead to easily take the overall win.

Team Associated B74.2D Team Kit
Vehicle Specs

P/N: 90037
Street Price: $529
URL: associatedelectronics.com

Height (as tested): 3.5 in. (90.2mm)
Length (as tested): 15.55 in. (395mm)
Width (as tested): 10.0 in. (254mm)
Wheelbase (as tested): 11.3 in. (289mm)
Weight: 3 lbs., 12 oz (1724g)

Scale: 1/10
Chassis: 7075 aluminum
Shocks: 13mm large-bore aluminum, adjustable, oil-filled
Suspension: Independent, front and rear
Front & Rear Differentials: Fluid-filled, steel bevels
Center Differential: Fluid-filled, plastic spur
Front & Rear Driveshafts: Steel CVA
Center Driveshafts: Steel universal
Bearings: Rubber-shielded ball

ADDITIONAL PARTS (Not Included)
Reedy Blackbox 610R Competition ESC (P/N 27016)
Reedy Sonic 540-SP5 13.5T Brushless Motor (P/N 27481)
Reedy Zappers LiPo 4800mAh 90C 7.6V LP Shorty (P/N 27396)
Reedy RT2007A Low-Profile Titanium Gear Brushless Hi-Torque HV Servo (P/N 27155)
Reedy Blackbox PROgrammer 2 (P/N 27027)
Reedy HV 30mm Aluminum Motor Fan (P/N 27457)
JConcepts Double Dees V2 2.2” Rear Buggy Tires (P/N JCO3159-02)
JConcepts Double Dees V2 2.2” 4WD 1/10 Front Buggy Tires (P/N JCO3161-02)
JConcepts Smoothie 2 2.2” Pre-Mounted Rear Buggy Tires (P/N JCO4017-2691)
JConcepts Smoothie 2 2.2” Pre-Mounted 4WD Front Tires (P/N JCO4019-2691)
Futaba 4PM Plus 4-Channel 2.4GHz T-FHSS Radio System (P/N FUT01004416-3)

FINAL WORD
After assembling, driving and racing the B74.2D, it’s easy to see why it’s a winner out of the box, not to mention a world champion. Throughout testing, the awesome buggy gives you exactly what you input at the controls, making it easy to drive at an ultra-fast pace. You can clearly feel every adjustment you make on the B74.2D, one change at a time, allowing you to get up to speed quickly on race day. In the hands of a pro, we witnessed the B74.2D win the biggest title in the world, and in the hands of an Average Joe this very capable buggy will excel and will grow with your skills. If you’re shopping for a 1/10-scale 4WD buggy, I suggest you take a serious look at the Team Associated B74.2D.

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Text and Images by Joel Navarro