Building the Ultimate Pro4 Truck!
The Short Course craze has done everything but slow down the last couple months. In fact, a whole new breed of SC trucks are becoming available in the form of 4WD. I had a great time driving the RTR version of the Jammin SCRT10 (see the full review in the December 2010 issue) but knew that this truck was begging for a few upgrades, some softer kicks and the addition of some really big power!
Baseline Setup
Beating…er, I mean testing the RTR version of this truck let me focus on what parts could use a little attention. While the truck handled and jumped pretty good in stock form, there is always room for improvement over the RTR equipment. This also allowed me to swap out the hard stock tires and anemic powerplant.
Electronics
Always the fun part of any build-up, I pulled the RTR electronics out and dropped in some race-level units. The stock servo was replaced with a Hot Bodies DSJ-2ST High-Speed. Not only is this servo fast, but it’s 222oz of torque should easily turn the SCRT10’s powered front wheels. To replace the huge 12T 550 motor and ESC, I loaded up the SCRT10 with Team Novak’s new Havoc Pro SC/Ballistic 550 Short Course System. This system was designed specifically for the new 4WD SC trucks coming out and is a direct replacement for the RTR equipment. To power all that heavy duty hardware, MaxAmps was kind enough to supply one of their new hard-cased 5250mAh 60C LiPo packs. You can order this pack with a different selection of plugs and balance ports for use with whatever charger you might have. And finally, to control all of this monster-power, I installed my trusty Airtronics receiver to grab the signal from my M11X.
Chassis & Suspension
The stock SCRT10 is a pretty stout truck. That being said, I left the stock chassis alone and went straight for the suspension. I gave Steve over at Team STRC a call and he hooked me up with all his killer aluminum parts for the SCRT10. These did add a little extra weight to the truck, but they did stiffen up the chassis quite a bit and make the SCRT10 pretty much bulletproof. On the front I installed a gunmetal STRC aluminum shock tower, steering knuckles, caster blocks and wheel hexes. To tighten up the steering, I used STRC’s complete aluminum steering set (with servo saver) and carbon fiber upper brace. In the rear of the SCRT10, a gunmetal STRC aluminum shock tower and hub carriers were installed. Front and rear gunmetal STRC aluminum braces finish off the chassis upgrades. Finally, Hong Nor aluminum threaded shock bodies were installed to help soak up the bumps. While all of these are not necessary to build a super-durable truck, they do look good and really help keep the SCRT10 in the reliability department. Plus, STRC’s fit and finish on the parts is second to none and really compliment the entire build.
Drivetrain
While running the SCRT10 in stock form, I didn’t really feel like the drivetrain was in need of any real upgrades. I did, however, pull the differentials out of the truck (yes, all 3) and fill them with a good, silicone-based diff fluid. I used 3000wt fluid in the front and middle differential and 2000wt in the rear differential. Once sealed, be sure to replace in the same direction you took them out. I’m not admitting that I did it wrong, I’m just saying … pay attention.
Body, Wheels & Tires
The body, wheels and tires are always the part that attracts the most attention (unless you’re kicking up HUGE roosts, which this truck was doing also!). For the rollers, I bolted on a set of JConcepts Tense wheels wrapped in AKA’s Wishbone tires. I love the look of the Tense wheels with the separate center ‘chrome’ piece. The look really sets the wheel apart from anything else out there. On a suggestion from a friend I gave the soft compound Wishbones a go. I decided to stick with the stock body mainly because I already had another clear one sitting in front of me. I had my local painter-extraordinaire Jaws, from Jaw Designs, throw down a coat of liquid goodness. As usual, he didn’t disappoint.
The Drive
As you might expect, strapping in more power and giving the truck more traction can only result in a bigger smile. As I set the SCRT10 down for the first time, I slowly rolled away from the edge of the track…ok, I’m lying … who ‘slowly rolls away from the edge of the track’ when they drop in this kind of race-level equipment??? Ya, me either. I pinned the throttle right off the bat and watched the SCRT10 rip down the straight. Acceleration out of the corners was fast and controlled thanks to the AKA Wishbones. This truck was now like my Nikon camera…basically Point and Shoot! It still had a little bit of a nose-down attitude over the jumps, but blipping the throttle as you left the face of the jump cured that. I think a little more tuning is in order to get it to jump consistently level, but that’s for another day. I had way too much fun kicking up dirt and flying high over the jumps!
Final Thoughts
The main reason for tweaking on the SCRT10 was to turn it into a solid race performer. In most cases, a well-built truck, decent power and some race-level tires are all that’s needed to get you to the winners circle. In MY case, however, I figured overkill was probably just right. My electronics package was a good fit for the SCRT10. The MaxAmps pack provides the Novak Havoc system with a ton or rip-roaring power, and the Hot Bodies servo can keep the front wheels in line without a sweat. The AKA Wishbones have an incredible amount of grip and can turn a mild 4WD offroader into a serious track terror. And finally, what can I say about the STRC aluminum parts other than they pretty much eliminate the high-wear plastic parts and give the SCRT10 a very solid feel. Oh, and they look great too! I’m pretty confident that when I attend the next race with my SCRT10, I’m going to have a truck that can make its way to the winners circle. However, I might need some upgrade parts to keep up with it!
Parts Used
Hong Nor
www.hongnor-racing.com–
• Front Threaded Shock Set, OFN40880
• Rear Threaded Shock Set, OFN40882
Team STRC
www.teamstrc.com–
• Aluminum Steering Bellcrank Set, STJ40834GM
• Aluminum Caster Blocks, STJ40839GM
• Aluminum Lock-Pin Style Hex Adapters, STJ40840GM
• Aluminum Steering Knuckles, STJ40841GM
• Aluminum Rear Hub Carriers, STJ40843GM
• Aluminum Center Bulkhead, STJ40844GM
• Aluminum HD Rear Shock Tower, STJ40870RGM
• Aluminum Front Chassis Brace, STJ40947GM
• Aluminum HD Front “Tall” Shock Tower, STJ40948GM
• Aluminum Rear Chassis Brace, STJ40949GM
• Carbon Fiber Upper Steering Plate, STJ40995C
AKA
www.raceaka.com–
• 1:10 Wishbone SC Soft Tires, 13001S
JConcepts
www.jconcepts.net–
• Tense 4×4 Front/Rear Wheel, 3324
Hot Bodies
www.hotbodiesonline.com–
• DSJ-2ST High-Speed Servo, 67992
Novak
www.teamnovak.com-
• Havoc Pro SC / Ballistic 550 Short Course System, 3115
Max Amps
www.maxamps.com–
• Hard Case LiPo 5250HC 2S 60C
Airtronics
www.airtronics.net-
• M11X, AIR90480
Jaw Designs
www.jawdesigns.com-
Gallery
