Duratrax certainly hit a home run when they released the 835 and 835E 1/8-scale buggies, these offer near race worthy performance at a budget price. While the buggies perform well against other similarly priced models, I often wondered if this buggy could make it out on the track against these purely race-bred vehicles. I figure with some chassis and suspension upgrades along with some proper race gear, the 835E will be able to hold its own against other vehicles you are likely to find on the track. The reason this Duratrax is a great gateway into club racing is that it is suitable for sportsman/ beginner races and then as the user gets used to what they like/dislike about this
particular model they can upgrade it as they see fit. I put together a list of upgrades specifically geared for racing, but feel free to pick and choose what is right for yours.
Words: Mark Ronge
Photos: Edwin Rodriguez
THE GOODS SUSPENSION/STEERING
The Duratrax 835e is a pretty competent buggy out of the box, but needs some parts in order to compete with higher end race ready rigs. One of the most important parts of racing is dialing in your setup, so the first order of business was to install front and rear CNC machined shock towers. These shock towers have different shock mounting positions than the stock units which are more geared for racing setups (five shock positions are drilled for the upper shock position). The stock spring setup is pretty stiff, the yellow medium set was added to the front and rear dampers which will help soak up the rough bumps easier. Because the buggy’s wheels are very exposed, one wrong
hit and the suspension arm’s hingepins can rip right out. Thankfully, Duratrax makes machined aluminum hingepin carriers for the front and rear of the 835 platform. After installing these, I no longer worry about any future hingepin issues.
When I race buggies I like to set up my buggy to have as much steering as possible, even at the expense of some stability. With that in mind I chose the two degree rear toe setup using the Duratrax machined rear suspension mount. A three degree set is also available which will allow for some added stability during turning. With racing, consistency is essential, which is why I wanted to revisit the front steering and started with replacing the steering
knuckles with the Duratrax machined aluminum ones. These provide increased durability over the stock metal cast knuckles. For smoother, less sloppy steering action the plastic hubs were tossed for the machined set as well. This
has the added benefit of some extra durability as well and because racing setups require frequent maintenance, the hubs will not need to be replaced as wear is a nonissue going forward. The rear hub carriers were replaced as well, purely for durability reasons.
To handle steering duty, I used a Futaba S9352HV servo. This servo is absolutely insane. It is more precise than the stock one and it more than handles my need for quick, snappy steering. Even though it doesn’t seem like a lot, the extra transit time is often very critical at high levels of racing. I also like that you can put an unregulated 7.4V of power through in order to gain extra performance from this unit.
ELECTRONICS
The stock Duratrax brushless setup is no doubt an awesome combo, but racers generally prefer sensored setups. The main reason behind this is that they offer an unmatched level of precise control at lower throttle settings. With such powerful brushless motors propelling 1/8-scale vehicles to the finish line, nothing is worse than a light pull of the trigger resulting in a delay in power or a surge in torque, both of which can happen with sensorless setups. I didn’t want to blowout my budget, so the Hobbywing Xerun 150A sensored ESC was definitely perfect and up to the task. This speed control can handle almost any 1/8-scale brushless motor (both sensored and sensorless) and it even has a cool feature in which the ESC will switch to sensorless mode on the fly to keep you on the track to finish the race if the sensor cable breaks or is detached in any way. It can handle 2-6 cell LiPos and has different throttle profiles and
timing adjustments that you would expect to see on race-quality ESCs. The motor I chose for this ESC is a sensored Hobbywing Xerun 4274.
This 1800Kv motor is decent midrange forracing buggies, and since I am using a 4-cellLiPo, runtimes will remain excellent and I willhave enough power and acceleration for thestraightaways to keep up with the nitros. The4-cell LiPo is a Trakpower 14.8V 5600mAhpack, which offers up to 60C of continuous discharge which is way more than adequate for the 150 amp speed control which remains. It will remain cool during long races, leading to more cycles during the lifetime of the pack.
A transmitter is the direct link between a vehicle and the racer and for this reason many upgrade the radio system in RTRs immediately. There is nothing wrong with the transmitter that comes with the 835 for bashing and backyard racing purposes, but for racing an upgrade is definitely needed. I like to use my Futaba 4PLS for racing duty, it has plenty of high-end features at a mid-range price. The radio system is rock solid and has never shown any signs of interference. It also features cool telemetry data and the lap counter is great for practice sessions.
FINSHING TOUCHES
Fitting with the racing theme, I got excited when I saw Duratrax makes a front brace out of graphite which looks way cooler than the regular unit and in theory, should add some rigidity to the overall structure. Most high end racing kits have a similar part, and after installing it I really started to see the potential in the 835. I remember when I first started racing I had issues with flexing in the chassis which led to all sorts of driveline issues, so I was very happy to install the Duratrax aluminum chassis brace over the stock plastic unit to eliminate any chance of excess flex while racing. After it’s all said and done the only thing that was missing is the most important factor in race vehicles, the tires. Because I want to try this buggy out on a variety of tracks, I couldn’t go wrong with a basic bar type tread. The Duratrax premounted Persuader tires come on dish wheels and the medium tread compound is a great balance of longevity and grip. These come at a very reasonable price as well. Finally, I set aside the RTR body and had a clear Duratrax body painted up by Kustom RC Graphics with a sweet racing paint scheme.
PARTS USED
DURATRAX
• 1/8 835E Brushless 4WD RTR (DTXD78**, $399.99)
• Machined Hub Front Carrier 7075 Aluminum (DTXC7976, $44.99)
• Machined Hub Rear 7075 Aluminum Gray (DTXC7977, $41.99)
• Machined Knuckle Arm 7075 Aluminum Fr (DTXC8180, $41.99)
• Shock Tower Racing Front 7075 Alum Gray (DTXC9298, $33.99)
• Shock Tower Racing Rear 7075 Aluminum (DTXC9299, $33.99)
• F/R Upper Suspension Mount 7075 Aluminum 835 (DTXC9328, $15.49) 2X
• F/R Lower Suspension Mount 7075 Aluminum 835 (DTXC9334, $15.49)
• R/R Lower Susp Mount 7075 Aluminum 2Deg 835 (DTXC9335, $15.49)
• Shock Spring Front Medium Yellow 835E (2) (DTXC8942, $2.69)
• Shock Spring Rear Medium Yellow 835E (2) (DTXC8943, $2.69)
• Chassis Brace Aluminum Gray 7075 Rear 835 (DTXC6636, $19.99)
• Front Brace Graphite 835 (DTXC6640, $12.99)
• Duratrax Persuader Tires (DTXC3651, $24.99)
TRAKPOWER
• 14.8V 5600mAh 83Wh LiPo Pack 60C (TKPC0450, $159.99)
FUTABA
• 4PLS 4-Channel S-FHSS Telemetry System + R304SB Receiver (FUTK1410, $249.99)
• 9352HV Servo (S9352HV, $129.99)
HOBBYWING
• Xerun 150A 1/8 Competition Sensored Brushless ESC (81020196, $99.99)
• XERUN-4274SD-1800Kv Motor (90060031, $106.99)
• XERUN-4274SD-1800Kv Sensored Brushless Motor (90060031, $107.99)
PERFORMANCE
The first thing I wanted to test was the low speed responsiveness because I now run the Hobbywing sensored power setup. I lightly pulled the trigger on the Futaba 4PLS and was happy to see the buggy crawl away at slow speeds. Any cogging or jerkiness from the system has been eliminated thanks to this sensored system. With the stock gearing, low
end power was more than anyone would need on any track and the top end was impressive, suitable for medium sized straightaways. This is also partially due to the Trakpower LiPo which remained cool during my testing and
never skipped a beat with its impressive 60C discharge rating. Luckily all my local tracks do not have super long straights so this is the perfect setup. Otherwise a quick pinion swap should sort things out. The Hobbywing ESC
has many tuning capabilities, all I wanted to add was some light drag brake and I was happy with the other settings. The Futaba radio system is flawless. I had more range than I could ever need and the Duratrax seemed to be more responsive to my inputs as well. Part of this is definitely due to the upgraded Futaba 9352HV servo which mates well with the Futaba radio gear.
All this extra power and control is worthless without a proper set of tires and I was impressed with the Duratrax Persuader tires. They were quite grippy, even in the unwatered sections of the track and after a bunch of runs they did not show excess signs of wear. This was crucial in the hairpin sections as I am running the above mentioned twodegree rear toe with a decently aggressive front toe so I needed all the grip I could get to avoid excess wheelspin. In these tight sections I noticed how much more responsive the buggy was than when it was in stock trim. It wanted to dive right into the corners and responded to the smallest inputs even throughout a turn. I also appreciated how
consistent my inputs were, sometimes with the stock plastic components when you turn in certain sections of the track you may get different outcomes, but with all of the CNC aluminum in the steering and suspension components this was virtually eliminated. I also gained a bit of control thanks to the lighter springs which did not impact jumping in any way. This upgraded 835 still jumps great, just like the stock version, and with the added tuning options the new shock towers gave me I could dial it in even more.
It only took one battery pack before I was laying down consistent lap times and ready for race day. After practicing, I inspected the vehicle and there was no damage as expected and that definitely gives me confidence that it can handle a full day of racing with no issues.
WRAP UP
When I first hit the track I was very happy with the results of all the upgrades that have been installed. It didn’t feel like a whole new buggy, more like a refined 835, which was awesome. It was way more consistent, which is the most important thing when running club races. Often I am not the fastest guy on the track, but laying down many laps without making mistakes has allowed me to finish ahead of the “faster” racers. The extra weight from the aluminum components did not seem to impact handling at all, and the extra tuning options (shock tower positions) and spring
change really allowed me to dial in the Duratrax to the way I like it. I absolutely love the Hobbywing sensored motor combination. The low end control is essential on smaller, more technical tracks and it still has enough power to blow by nitros on large straightaways. Also, the Futaba radio gear and servo paired with the Duratrax upgrades made for the quick, snappy steering I like on my 1/8-scale racers. The best part of this project? When people at the track ask me what I am running and I can proudly say it’s a Duratrax!
LINKS
Duratrax, distributed exclusively by Great Planes Model Distributors, duratrax.com (800) 682-8948
Futaba, distributed exclusively by Hobbico, futaba-rc.com (800) 682-8948
Hobbywing Technology Co., Ltd., hobbywing.com
TrakPower, distributed by Great Planes ModelDistributors, bestrc.com (217) 398-8970
Kustom RC Graphics, www.kustomrcgraphics.net
