The fastest I've ever gone with a TC3 is probably 65mph at the Indianapolis Velodrome. Any motor can make a car go fast with a long enough straight and tall enough gears. I probably could go 60+ with a 2S 5000 mah lipo and a 10.5 motor.
Here are some suggestions.
Check out the Car Action World's Fastest RC Car Challenge! forum here (http://forums.radiocontrolzone.com/f...play.php?f=342
- The high speed shouldn't be an issue for the diffs, but I would suggest putting in the white gears (TC3/4/NTC3) as they are designed to be more durable.
- If you are using a carbon fiber drive shaft, make sure that nothing can rub against the shaft. At extremely high RPM the shaft WILL WOBBLE!
You will want to pay special attention the the servo mount that is closest to the drive shaft. I would suggest mounting the servo like is recommended in a FT TC4 by removing one of the servo mounting tabs. Please refer to page 15 of the FT TC4 manual found here (http://aedownloads.com/downloads/man...4ft_manual.pdf
- Another option is an aluminum drive shaft. However, even the aluminum shaft can wobble/bend at extremely high RPM if it is out of balance. DO NOT
rev the motor up with the car off the ground.
- The best option for the drive shaft is a titanium drive shaft. Niftech used to make them, but I believe that they may be out of business.
- If you are going to be using a tub chassis TC3, you may need to dremel the chassis webbing that sits underneath the pinion gear to allow for clearance.
- Look for the smallest spur gears that you can find to help overcome the 2.5 internal gear ratio on the TC3. With the popularity of brushless at this time, you should be able to find small spurs from Robinson Racing or PRS. They both should have 64 pitch spurs around 72 teeth. Buy a few extra just in case.
- As far as motor/battery, I really can't recommend anything. When I ran my TC3 on the Indy Velodrome, I was geared to make run time with a 10t motor/3300 batteries. I believe I averaged over 60mph on a 4 minute run on a track with a 1000ft runline. If you want to figure out your potential top speed, check out this calculator on Team Associated website here (http://www.teamassociated.com/racerh.../JavaMath.html
). If you need to figure out the RPM of a Novak brushless motor, check out their chart here (http://www.teamnovak.com/products/br...spec_chart.htm
). Remember that potential RPM and usable RPM are different. Using conservative numbers, a TC3 geared at 72 spur/60 pinion with a motor turning 41000 RPM, you should be able to reach 101mph. That is assuming you have enough room to get the car up to speed.
- I would also recommend using a receiver battery. When running such high RPM, the draw on the battery can cause a dip in voltage and put the receiver into failsafe. By running an external battery for the receiver you should avoid losing contact with the car. At a minimum, you will want to set your failsafe on your receiver in the event that you do lose contact with the car to hit full brakes so that the car doesn't becomes an un-manned missile.
- You should at a minimum use belted touring car tires to prevent ballooning at high speed. Different manufacturers make belted slicks. A better option is to use capped touring car tires. BSR can make capped tires - here is a link to their website (http://johnsbsrracing.com/
- Look for a very stable body without too much downforce. The typical TC body will have too much overal downforce and just slow you down. Too much front downforce will give the car oversteer at high speeds. I'd suggest a high speed Velo Nascar body. I believe McAllister Racing (http://www.mcallisterracing.com/racing/
) makes one. You will want to add a wing to the rear of the car with LARGE side dams to help the car be more stable.
- Lastly for every 5mph over 50mph, expect to spend money. Not only do you have to have your car setup well, at those speeds you are beginning to fight wind resistance.