R/C Tech Forums - View Single Post - Losi Constant Velocity Drive (LCD) vs MIP CVD
Old 12-18-2005, 02:38 PM
  #59  
John Stranahan
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The foam durability depends a lot on the skill level of the driver. The tire fails when it chunks or loses a bit of foam. At this point the car does not handle as well although there is plenty of tread left. If you rarely crash in a race they hold up pretty well.

The rubber tires hold up very well. Takeoff CS 27 and 32 tires hold up exceptionally well. I am always glad when the temperature is right for CS 27s. 30 runs (battery packs) on a set. Sorex 32's are a bit better than CS 32 traction wise, but they wear out a bit quicker. Note that a rubber tire is fastest brand new in the first race. Don't waste this new rubber on practice. Only take 1 or two tryout laps. The number is the celsius temperature the tires are designed for. When you run mod the tires heat up more and may require a rating higher than the track temperature.

The Lipo battery that I purchased is a Scorpion with 3200 milliampere-hour (mA-h) of capacity. Some NiMH packs have higher capacity. Orion is coming out with a Lipo with 4800 mA-h of capacity. They probably had this cell designed as large as possible to fill the standard battery tray on the touring car. My Scorpion pack is smaller than the tray. I don't like the built in connectors of the Orion pack as they tend to get loose and can come unconnected in a race. I would rather have two solder terminals or two pigtail wires.

Some guys at Reflex which was an indoor asphalt track (high grip) were actually dumping a 3000 mA-h battery in 19 turn class in 5 minutes (well actually just Tommy). A Novak Sportsman brushless would probably give you about another minute if geared to the same performance as the fellows 19 turn (It would give me several more minutes as I gear a little lower) at Reflex. Outdoors with less traction more minutes still. The Orion Lipo would give you two more minutes above this Scorpion pack (again most guys would get a few minutes more), estimate is 9 minutes indoors maybe 10-12 outdoors on a dusty track. It is best, in my opinion, especially for a sportsman class, to time the race short enough so everyone finishes without dumping as this is a frustrating thing to happen to a car that is running pretty well..

A good thing about NiMH packs is you don't need too many. They get faster with each run on a day, so you can just get two. One is charging while the other is running. Some lag time in between for motor cooling and charging.
With a Lipo, it takes forever to charge, they are real expensive right now, They need to be run right after charging for the best voltage. You might need more than two for a pleasurable outing and also two chargers. There is a large decrease in Voltage after only 15 minutes delay from charge to run. Timing the charge during a race is going to be crucial so it peaks at the right time. A NiMH you just repeak if needed. Repeaking is not reccomended for a LiPo and is a very slow process as well. The Lipo characteristics, I have only learned recently after purchasing and testing one. I don't think running LiPos is going to be cost effective. From the construction and material costs they seem to me like they should be cheap to produce. Don't know why they want to charge us a billion dollars for them.
I plan to use my radio's timer to see how long this Scorpion Lipo will run a stock motor before performance falls off. Tomorrow. I'll have some data on a GTB 6.5 and the Lipo later on.

So here is the test plan TC3 stock untill I get back pretty good again. TC3 mod with brush motor and Lipo, TC3 with GTB 6.5 and LiPo, the Losi JRXS GTB 6.5 LiPo. This is going to take some time, but I will enjoy every minute on the track.

The photo is of my favorite wheel. Not so hard that it is brittle, not too soft, so it does not stay bent after a crash like a soft wheel. Looks great. CS tires also come premounted on this wheel, I believe. Could not find a supplier with a photo to verify this. Tires are CS 32's with nine runs. When you run CS tires its important to have a long lasting wheel or the wheel will break before the tire is worn out. I'm getting to the paint on the body. Goofed up the trimming of the sides of the first body. Note the 48 pitch gears for use outdoors.

I have since learned that Takeoff's come on Speedmind wheels. The closest one to this wheel is the mesh wheel. I hope it is equally durable.
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Last edited by John Stranahan; 01-04-2006 at 05:36 PM.
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