Project: HPI Vorza Build

This RTR Now Stands For Ready-To-Rule!

HPI released the Vorza Flux RTR as an out-of-the-box, ready to go 4WD 1/8 e-buggy. Using the World Championship winning Hot Bodies D8 to set the groundwork, the Vorza definitely has the bloodlines of a true race car. Some people, however, snub their noses at its RTR designation. Ready-To-Run can’t mean competitive race car, can it? We’ll see, as I build up a competition-ready Vorza. I will be using a modified version of Atsushi Hara’s World’s winning D8 setup. Yes, I did say I will be tweaking on the World Champions setup. I’m crazy like that.

Baseline Setup
To see if my Factory upgrades would turn my RTR into a competition-level buggy, I needed to have a baseline to compare to. I set off to Pegasus Hobbies (in Ontario, California) to put in some laps and get a feel for the way the Vorza handles in stock form. Baseline testing was with a completely stock car including tires, electronics, gearing and setup. The Vorza felt pretty good around the track…it was really fast (even on a 2-cell LiPo), had decent steering and jumped well, but felt a little numb (for my driving) in any type of hairpin or chicane. The stock tires also felt like they were really grasping for grip on the dry track. After a couple battery packs, I pulled the Vorza off, packed up and headed to the house for a complete vehicle teardown and rebuild.

Electronics
I decided to keep the ridiculously fast 2200Kv Flux motor and Blur electronic speed control. This system has tire-shredding power and is proven to be very reliable. To add a little umph, I mated this system with a 5200mAh 50C Thunder Power Pro Race 4S LiPo. While this sounds a bit overkill (and it surely was), I feel you can really never have enough power! To improve the steering, HPI supplied one of their SF-32TT Digital competition servos. This performance servo features a full titanium gear train, purple heat-sinked case and a whopping 333oz of torque. I also replaced the stock plastic unit with a Hot Bodies Aluminum Steering Servo Horn. To control the Vorza, I hooked up HPI’s new Spread Spectrum DSSS 2.4GHZ Radio system. This new system features crystal-less operation, a built-in fail-safe, dual rate, servo reversing and a low battery warning. While this system is not yet available as a stand-alone unit, I did find out that HPI will be releasing it in the near future.

Chassis & Suspension
How do you improve upon World Championship winning suspension setup? I’m not sure you can, but you can make it look good! First off, I’m certainly no Atsushi Hara, and I’m man enough to admit to that. But I do like to go as fast and attempt to make the same jumps as him. However, with all this power, I’m pretty sure I’m going to crash about 100 times more over a race weekend than he will! Luckily for all of us (even though I’m thinking it was planned this way), a ton of the Hot Bodies D8 hop-up parts bolt right on to the HPI Vorza. HB Aluminum Front Spindles and Lightweight Kingpin Bushings were installed to save a little weight out near the front wheels. A set of HB Lightweight Sway Bar Holders were also installed on all four corners, as well as a set of HB Lightweight Shock Stand Offs. To round out the front, a set of HB Lightweight Steering Posts were bolted on. Even though you can’t really see them, alone these steering posts save quite a bit of weight. On the rear of the Vorza, a new HB High Mount Aluminum Shock Tower was installed along with a set of 112mm Big Bore Shocks. By installing these longer shocks (in conjunction with the tower), you add more droop in the rear of the car. This option helps stabilize the Vorza on slicker tracks.

Drivetrain
The stock drivetrain is surprisingly reliable with all the abuse the Flux system dishes out, so durability wasn’t really an issue. Instead I decided to lighten up the drivetrain to make the most of the Flux power. Each differential was disassembled and rebuilt using a Hot Bodies Lightweight 43 Tooth Spiral Bevel Gear and Lightweight Outdrives. Using Hara’s setup, 3000wt fluid was added to the front diff and 1000wt added to the rear diff. In addition to the 4000wt fluid added to the center diff, a HB Lightweight 48 Tooth Spur Gear was installed in place of the heavier stock unit. Running down the spine of the Vorza,I added a HPI DCJ Center Driveshaft to the front and WCE Center Driveshaft to the rear. These shafts help transfer the power more efficiently to the front and rear differentials. To finish off the drivetrain upgrades, Hot Bodies Lightweight Wheel Hex Hubs were installed behind each wheel.

Body, Wheels & Tires
The stock body already comes ready to go with some killer graphics. To keep things somewhat simple, I pulled out my trusty heat gun and carefully removed the stock stickers, making sure to not leave behind any residue. Once completed, a fresh set of Xplosion 1/8 Buggy graphics from XXX Main were laid down on the stock silver body. I set aside the stock tires in favor of a set of Hot Bodies Megabite Tires in the Red Compound. These tires were stuffed with a set of HB’s Pro Molded Inner Foam (also in the Red Compound) and glued to a set of HB Yellow Wheels. A matching Yellow 1/8 wing, from the Hot Bodies Lightning series, was stickered up and bolted on.

The Drive
Another test session was scheduled for a sunny weekday afternoon back at Pegasus Hobbies. Someone, however, didn’t mention this to the stormy weather that decided to roll in. I arrived at Pegasus to find a damp track with some pockets of thick mud. My first thought was to reschedule, but I just figured “Hey, it’ll be ok…I’ll just stay away from those areas”. I should have rescheduled.

Once back on the damp part of the track, the Championship-winning suspension setup and soft Megabite tires turned this reliable RTR into a fast-lap hero. The acceleration was brutal, thanks to the Flux/Thunder Power combo. This combo also allowed me to turn double jumps into triple jumps, and while not necessarily faster, was way more fun! Steering was much better, too, and the Vorza felt more nimble through the chicane section on the track. One noticeable area was how stable the Vorza felt. The addition of the High Mount Rear Shock Tower and 112mm Big Bore Shocks really planted the rear of the car. I feel this is one of the best upgrades you can bolt on!

Final Thoughts
The objective of this build was to turn a Ready-To-Run vehicle into a competition-level race car. Hara’s setup alone would probably get you on the right track, but for that additional advantage, you can’t beat a lightweight car. If you were to weigh all the lightweight parts individually, you’d feel like you won’t save that much weight. But if you weigh all of them as a group, you’ll certainly notice a significant difference. Lighter weight translates to a faster, more efficient car, and I can definitely say that the Vorza felt quicker off the line, faster down the straight and better in the turns than the stock car. I think the best part about this type of build is that you can upgrade as your budget allows, gradually building your race-ready ride. This not only transforms your RTR to a lighter weight vehicle, but also gives the feel (and looks) of a full Factory Ride.

Parts Used
HPI
hpiracing.com–
• 2.4GHz DSSS Radio System,
• SF-32TT Digital Competition Servo, #102490
• DCJ Center Driveshaft, #67217
• WCE Center Driveshaft, #67178

Hot Bodies
hotbodiesonline.com–
• Aluminum Steering Servo Horn, 67169
• Aluminum Front Spindle Set, #67216
• Lightweight Steering Posts, #67195
• Lightweight Shock Stand Offs, #67202
• Lightweight King Pin Bushings, #67201
• Lightweight Sway Bar Holders, #67207
• High Mount Rear Shock Tower, #67210
• Big Bore Shock Set, 112mm, #67298
• Lightweight Diff Axle Shaft, #67211
• Lightweight Wheel Hex Hub, #67196
• Lightweight Spur Gear 48 Tooth, #67190
• Lightweight 43 Tooth Spiral Bevel Gear, #67191
• Lightweight Out Drives, #67197
• Megabite Tires, Red Compound, #67758
• Pro Molded Inner Foam, Red Compound, #67773
• 1/8 Deck Wing, #HBC8051

Thunder Power
thunderpowerrc.com–
• 5200mAh 50C Pro 4-Cell/4S 14.8V, TP5200-4SPR50

XXX Main
xxxmain.com–
• Xplosion 1/8 Buggy Red, W003R

Pegasus Hobbies
pegasushobbies.com–
(909) 982-6507

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