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Project: The Ultimate LST2 Race Truck

8/6/2007 by Gary Katzer

Copyright:© 2007 Horizon Hobby, Inc.

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In this article...

Page 2: Chassis
Page 6: Getting the Power Down
(continued from previous page)
Shot of the mounted Losi King Pins

We used Losi’s Super King-Pin tires combined with Losi 2-stage inserts. This combination really hooked up well on our test track.

90% of your overall setup and performance is directly related to the tires that are bolted onto your truck. Racier tires will help provide more grip on racetracks. For this truck, I installed a set of Losi Super King Pin tires on 420-sized wheels. I did swap out the foam inserts included with the tires in favor of Losi’s 2-Stage tire inserts instead. Depending on the rules for your particular track, you might have the option of running truggy tires. If different tires are an option, you’ll definitely want to experiment with Losi’s XTT Truggy Tires from the Team Losi Racing 8IGHT-T. To install the 8IGHT-T wheels, you’ll need to swap out the 23mm wheel hexes with 17mm units. You can use the hexes from the 8IGHT and 8IGHT-T kits to accomplish this. The XTT tires are narrower and feature a shorter sidewall than traditional monster truck tires, which also translates into a lighter weight tire with less rotating mass.


Rear shot of the Ultimate Race LST2

This is a view the competition needs to familiarize themselves with.

Tuning Your Differentials

One of the most outstanding features of the LST2 is the drivetrain system. Taking cues from 1/8-scale buggies, the LST2 features sealed front and rear differentials that can be tuned by using different viscosity oils. Generally speaking, you’ll wind up using thicker oil in the front differential than what you’ll use in the rear. By filling the front diff with thicker oil, the front end of your truck will be desensitized and steering will be taken away. Using a thinner viscosity oil in front will allow the spider gears inside the differential to turn with less resistance, in turn providing you with more steering. The exact same principles are true in the rear differential; thinner oil in the rear differential will aid in providing more rear grip, while thicker oil will tighten up the diff action and reduce your rear grip.

To increase the strength and durability of this truck, I swapped out the stock steel steering rods for titanium ones. Titanium turnbuckles add strength to your steering, while the larger hex on the turnbuckle makes toe changes easier. Speaking of titanium, titanium nitride coated gears have improved wear characteristics while adding some flair with their gold tint.

Subtle Tweaks

Along with making broad changes to your truck, there are subtle refinements that, when combined, help smooth out the performance of your handling and make your truck more consistent. I installed the LST2 rear wing kit on this particular truck for several reasons. A wing will add rear downforce to your truck in comparison to the stock spoiler. Beyond the additional downforce provided by the wing, the side plates and vertical fins add straight-line stability too.

The final tweak to the truck was something added at the last minute. The stock brakes work well, but I felt there was some room for improvement here too. I removed the stock steel brake pads and replaced them with the High-Performance Brake Pad Set. These pads are the same size and dimension as the stock units but are made of a more abrasive material. The new brake pad material should help “whoa” the truck down in less space than the stock units.