While we’ve had a fantastic time bashing the ECX 4WD Circuit at the local park, it does come with brushed power that isn’t very fast. Like most people, we are always longing for more speed, therefore we decided to do a few modifications to see what it would take to break the speed limit. Hit the READ MORE to see what we did to get some serious speed out of the 4wd Circuit, and watch the video.
1. The stock tires aren’t bad for normal driving, but at high speeds they tend to balloon and make the truck hard to drive. We ordered up 2 pairs of Jaco Foam Tires to make our truck easier to drive and to give it better traction on paved surfaces. We also applied some Pro-Line tire glue to the outside wall of both front tires. This takes away some steering and makes the Circuit even easier to drive when at full tilt. Price – roughly $80.
2. The front end of the truck tended to lift when going really fast so we took the pre-load spacers from the front shocks and popped them on the rear. This really stiffened up the rear suspension and kept the truck from trying to wheelie over backwards. Price – Free!
3. After changing the pre-load spacers, we noticed the rear was under-damped (too bouncy). We poured out the stock oil, put in Associated 40 weight, and the rear shocks performed much better during speed runs. Price – $3.
4. Many overpowered speed run machines want to wheelie out when pinned wide open. We grabbed an old Traxxas Slash chassis and cut out a strip of plastic. We then removed the stock rear bumper on the Circuit and mounted the strip in its place to act like a wheelie bar. Price – Free!
5. The stock pinion has 12 teeth, we geared up and popped on a Castle MOD1 15 Tooth unit. Yes, this gears the Circuit to the moon, carefully monitor motor temps any time you run with high speed gearing. You’ll also need to run this Robinson Reducer Sleeve to make it work. Price – $12.
6. While there was not room to drop the front of the body any lower to the chassis, we did lower the rear body mount one hole. Price – Free!
7. To go really fast, you need really big power. We dropped in a Castle Creations Max Pro ESC with 7700kV Motor and a Dynamite 3S LiPo battery. This is a crazy fast set-up not recommended for new drivers or for those with a weak stomach. Price – CC brushless system $195, Dynamite 3S LiPo $120.
8. We turned the travel down for steering on the transmitter. This also makes the 4WD Circuit easier to drive at high speeds. While doing speed runs you don’t need a lot of steering and the last thing you want is to steer abruptly and flip your truck. Price – Free!
How fast did we go? Our trusty radar gun clocked the 4WD Circuit at 71 mph. Not too shabby for some minor mods, very little time, and not spending a truckload of cash. Perhaps the bigger news was that it was relatively easy to drive at that speed. We were able to make pass after pass without flipping over backwards or crashing.
Check out a quick video here:
Want more information on the ECX 4WD Circuit? Simply Click Here to visit the 4wd Circuit page on the official ECX website.
Up for reading some more “how-to” articles? If so, check out This Link on BigSquidRC.