Articles

The Revolutionary Team Losi JRXS Type-R

Posted:  Monday, October 16, 2006
Copyright:© 2006 Horizon Hobby, Inc.

Team Losi has a long and storied history in on-road racing. From the first-ever ISTC IFMAR World Championship-winning car, the Street Weapon, multi-time National Champion XXX-S, and now the JRX-S, Team Losi knows how to get it done. The latest car to come from the Team Losi garage, the JRXS Type-R, is a refined race machine designed to be an all-out winner. From the earliest tests to its performances at prestigious events such as the 2006 Snowbirds, 2006 ROAR Nats, and the 2006 IIC, the JRXS Type-R definitely stands out in a sea of copycats.

Revised Layout

The most noticeable difference between the original JRX-S and the JRXS Type-R is the placement of the motor and the battery. The motor and battery pack are both still placed along the centerline of the chassis, keeping the polar moment of inertia as close to the centerline of the chassis as possible. However, the motor has been relocated rearward, just in front of the rear differential, and now the battery pack is shifted forward. There are several key reasons why these changes were made. By relocating the motor rearward, the JRXS Type-R has exceptional bite from the middle of the corner off, allowing you to get on the power sooner. Additionally, moving the battery in front of the motor reduces the weight transfer to the nose of the car under braking, preventing the JRXS Type-R from feeling loose or suffering from an over-steer characteristic.

In addition to the layout change, the upper and lower chassis plates have also undergone some revisions as well. The new upper and lower deck chassis configuration has a much lower CG than most other touring cars, which again adds to the JRXS Type-R’s stable yet nimble feel on-track. The upper deck has a slammed look to it, which was partially accomplished by relocating the steering bellcranks from underneath to on top of the upper deck. This change eliminates the need to provide clearance for the servo and bellcrank arms.

Four side braces tie the upper and lower decks together with eight total screws; one each to the top deck and one each that comes up through the battery tray and holds it in place. The four upper screws can be used as a tuning aid, as removing the screws that pass through the upper deck can allow the chassis to have more flex. On some surfaces, this increased flex can increase grip and improve the handling of the car. The upper deck connects to the front and rear aluminum bulkheads instead of screwing into a plastic piece. This eliminates the possibility of a screw stripping out a plastic bulkhead, as can happen on some other cars. Finally, the new rear aluminum bulkhead and motor mount design now allows racers to use clip-on heat sinks, fans, or other devices to help reduce motor temperatures.

Revised Drivetrain and Bulkheads

One of the most unique tuning features of the original JRX-S was the option of altering the height of the differentials. This feature returns on the JRXS Type-R, but with some subtle revisions. The height of the diffs is now infinitely adjustable thanks to the new clamping front and rear aluminum two-piece bulkheads. The differentials have also undergone some changes as well, as new diff outdrives and tubes have been designed for the Type-R. The new differential tubes have been lightened and strengthened to better withstand the abuse and torque put out by the latest generation of high-voltage batteries and low-turn motors. Adjusting the differential tension is easier too, as the new differential tubes make accessing the diff adjustment screw easier. Drivetrain efficiency has been further improved thanks to new drive belts. The front and rear belts feature a new, low-friction design for improved top speed and acceleration. The final drive ratio of the JRXS Type-R remains unchanged at 1.83:1

Team Losi raised some eyebrows when they first unveiled the patented LCD driveshaft in the JRX-S. The LCD returns on the Type-R, but they are now lengthened to accommodate the longer suspension arms. In terms of driveshafts, Team Losi has raised the bar even further with the JRXS Type-R by turning their “outside the box” thinking style to the rear driveshafts. The rear of the Type-R utilizes long-span RCD’s (reverse CVD’s) to minimize wear and make the driveline even more silky smooth. The RCD’s also keep the rear of the JRXS Type-R flatter in the corners along with improving on-power steering. The JRXS Type-R uses new metric axles, eliminating the need for racers to ream out their wheels before using them.

Updated Suspension

The original JRX-S was well known as a car that changed direction very well, thanks to its central weight placement. When the decision was made to develop a rear motor chassis, this was one of the key handling characteristics that engineers strived to maintain. Much of the development time has gone towards making the JRXS Type-R a car that works well on rubber or foams, asphalt or carpet. New, longer A-arms come as standard equipment and alter the roll characteristics. The A-arms are molded out of Team Losi’s exclusive EA3 composite for exceptional durability and minimal flexing. The new longer arms also feature the additional lower shock mounting that team members had first developed on the original JRX-S.

The front suspension of the JRXS Type-R has also been tweaked for the best possible performance. The front camber links utilize the all-new JR mounting position which was developed by the one and only Gil Losi, Jr. This type of upper camber link provides additional front stability on high bite surfaces by reducing slop and flex. The Type-R also includes aluminum suspension mounts that can be flipped to change the roll center. The new aluminum mounts also allow users to utilize the shorter A-arms of the original JRX-S by providing a more outboard hinge pin mounting point, providing you with yet another tuning option. Out of the box, the JRXS Type-R is configured for carpet racing on foam tires, but with a little tuning the JRXS Type-R can be easily dialed in for rubber or foam tires, asphalt or carpet.

Awesome Accessories


The JRXS Type-R is one of the most tunable and customizable chassis you can find. It features a ton of tuning options, including roll center changes, wheelbase, anti-squat, pro-dive, shock angles and more. The JRXS Type-R also features a ton of cool accessories and features too. The JRXS Type-R has been designed with the latest generation of Li-Po batteries in mind, such as the Team Orion Platinum Li-Po. With this in mind, the JRXS Type-R includes two new battery trays, one for sub-c batteries and one for Li-Po packs. Sedans are well known for over-taxing and over-heating motors which can cause your car to slow down or flatten out over the last few minutes of a race. There are clip-on heat sink fans out there, but often a solid hit can knock your fan or heat sink off the motor where it can get wrapped around an A-arm. The JRXS Type-R has one of the most unique cooling fan setups possible, with a total of three fans that can be bolted to the rear bulkheads themselves (1 to the can, 2 on the endbell). This is a much more secure and efficient setup than a heat sink mounted fan as well. Finally, you have two different options in how to connect your servo to your bellcranks. The first option is to use a steering arm that has a spring-loaded servo saver incorporated into it. The second option is to use the optional rigid link, which provides a direct connection from the servo to the bellcranks. This setup was designed with the expert racer in mind. If you find yourself hitting the boards frequently or use a nylon-gear servo, stick with the servo saver. For drivers that rarely need to be marshaled or crash, or that use high-quality metal geared servos, you may want to give the rigid link a try.

Designed With the Racer in Mind

Here at Team Losi, we’re racers too. We know that you don’t want to lay your hard-earned money out for something you won’t or can’t use. Many other racecars include wheels, tires, and bodies that never get used. Even though you’re never going to use these parts, you still pay for these items as the cost is figured into the price of the kit. The JRXS Type-R was designed from the ground up to be an all-out racecar, meaning that the choice of wheels, tires, and body is left up to you. By doing this, Team Losi was able to keep the cost down while still including some trick bonus items (aluminum suspension mounts, aluminum bulkheads, Li-Po tray, etc) making it an even better value. Add in the fact that since the Team Losi JRXS Type-R is made in the USA, finding replacement parts is as easy as heading to your local hobby dealer, and you should find exactly what you need right there on their shelves.

From the Mouths of the Racers

The Team Losi JRXS Type-R didn’t just happen on its own. Many people have spent time testing, developing, re-testing, and racing prototype cars in different stages of development. This extensive testing has led to the development and creation of the car you see here and on the track. Recently, some of the drivers who have been involved with the car sat down to share their feelings.

Todd Hodge:

I have been involved with the testing of the JRXS Type-R from the very beginning. We have worked very hard to learn as much as there is to learn about our centered weight platform. By having the motor in the rear of the car, it increased our rear traction while also providing better on-power steering. The longer arms make for a much smoother and stable car which gives the end user more consistency. The narrow diffs and longer dog bones also help the car hold a better set into the turn, increasing corner speed. Overall I am stoked that we finally have new aluminum bulkheads and suspension mounts. Now, there are no more worries of stripping bulkheads. I cannot wait to go race the production car throughout the 2007 racing season.

Mike Truhe:

The JRXS Type-R has been the best touring car I have driven, by far. It has the perfect balance of steering and traction for any level of grip you are racing on. I have been competing in The Reedy Touring Car Race of Champions for the last 4-years and, while I have always been close to winning, I had always come up a buck short. This year (2006), I was not only able get up towards the top; I was able to finally be on top of the podium— thanks to the Team Losi JRXS Type-R. My car was unbelievable to drive, even for an off-road guy who doesn’t dedicate a ton of time testing on-road cars. The Team Losi JRXS Type-R is just that easy to go fast and adapt to!

Andrew Grey:

The JRXS Type-R equals dialed! After a year of development, the Type-R is ready to tear up carpet and pulverize asphalt tracks around the world. Its versatile chassis makes adapting to any track conditions a breeze. The JRXS Type-R has the perfect balance of steering and consistent traction, making this dope ride unparalleled on tight high bite carpet tracks. With the motor and batteries being in the center of the car, the chassis response is lightning quick, making the car transition left-to-right on the drop of a dime. Maintenance on the JRXS Type-R is a snap: 4 screws and the diffs come out. The drivetrain is ultra efficient, so run time isn't an issue either. Ready to win? Then you’re ready for the JRXS Type-R!

Mike Dumas:

The JRXS Type-R was obviously designed to be the most efficient chassis on the market, not just drivetrain-wise but corner speed-wise as well. The Type-R is really nimble, thanks to the weight being down the center of the car. This in technological terms is called moment of inertia. With that being said, this is the only car produced like this at the moment. The car is more efficient and very easy to work on with this design. I have run other chassis, and the JRXS Type-R is one of the easiest cars not only to maintain, but also is very easy to drive fast. The JRXS Type-R changes direction unlike any other car out there. I am sure anyone who drives one should feel the same. Good luck to all, and remember have fun.

Kevin Hebert:

Since I started running the JRXS Type-R, my results have seriously improved. I qualified for the A-main at two National events in the last year; one being on carpet and the other on asphalt which means the Type-R is definitely good on both surfaces. What I like about the Type-R is that you can find a lot of steering and still have a car easy to drive. Another great thing about the JRXS Type-R is that the setup I run stays almost exactly the same from track to track, which makes life a lot easier.

Paul “Chicky” Ciccarello:

My JRXS Type-R is so awesome! It is really easy to drive fast and always has the traction and steering I need to get the car to the front of the pack. It is easy on motors, and I have more run time left with this car than my other competitors because the car is so efficient. I love the fact that you can take the motor out without having to remove the batteries. Also the new aluminum bulkheads allow the diffs to be removed from the top, making rebuilding them a snap. The JRXS Type-R will for sure be at the top for a long time.



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