Anyone here into ZipZaps?

I'm getting into an amateur mini RC car racing league. The only cars authorized are the radioshack ZipZap series, and nearly everyone (including me) is buying the SE model. So my question is, does anyone here know how to hot rod these suckers? I've already figured out how to run the controller/charging unit with five AA NiMH cells instead of four AAAs, which is the stock setup. This should provide the same voltage with better charging capacity and quality. Plus I already have a complete NiMH charging setup and batteries, and I don't care to buy AAAs. I guess the car itself runs with a single internal NiMH cell, I think it's around 900mah. I don't have the car yet, it's still in the mail; but I can provide more details when I'm able to rip it apart.

RC forums have been less than helpful; the boards relevant to mini RC cars tend to be populated by teenagers, so that's why I'm posting here. I also ordered the different selection of motors and gear sets, but I'm looking for ideas to improve power train efficiency, resulting in longer/stronger runtimes. I want to dominate because I love to race.

I played around with knock-off BitCharGs last year, including some fiddling with the electronics. I don't know how much of this info transfers to ZipZaps.

Be careful when you open it up. The steering wires are fragile and impossible to repair.

The stock battery may be NiCd or NiMH. If it's NiCd, you can get a "free" capacity increase by dropping in a direct NiMH replacement. Increasing the battery voltage greatly increases available torque and max RPM. This is to the point where a car loaded with 2 or 3 standard batteries can drive quickly over carpet and do jumps and loop-de-loops. Someone found a battery size where 3 would replace the stock battery with a little coaxing. A little less than 1/3 runtime, a tiny bit more weight, and crazy power. A side effect of increasing voltage at the battery is that the steering "strength" is increased, so you can run multiple steering springs and make the car less susceptible to terrain.

The stock transistors for switching the motor in both real BitCharGs and knock-offs have a relatively high Ron. Swapping these with power MOSFETs reduces the Ron and voltage drop across the transistor, leaving more voltage for the motor. This mod greatly increases the available power, though not as much as tripling Vbatt.

I have 4 digiq cars and 2 tanks

a modded zipzap se hits around 3.4 mph (stock 2.5 mph)

digiq go 4 mph and they are smaller(almost 5 mph with digi propo controller)

http://www.the-gadgeteer.com/digiq-microir-car-review.html

zipzaps look a lot nicer more like real car models.

External fuel tanks work wonders...

Way to go Jarhead! it figures.

NewBie,

ROTFLMAO /ubbthreads/images/graemlins/crackup.gif Looks like my old hotrod.

I had one of the RS cars last year. I tweaked it a little then put a chrome body on it and my GF snagged it (damn, anything shiny). Haven't seen it since.

How did you tweak your RS, Lunal Tic? A "RS" is a ZipZap brand car, right?

Hi Edison,

I didn't do anything fancy. They (Radio Shack)had a kit with a bunch of gears, motors, tires and such. Plus I has some parts from another car. I mixed and matched till got something fast but controllable. A big problem is traction just like my old hotrod. I thought about finding some sponge tires but like I said the car kinda disappeared. /ubbthreads/images/graemlins/ohgeez.gif

Good luck,
LT

Guys,
Ages ago my brother was a fan of slot cars. I remember tales of motor rewinding and balancing.

Take some of the wire out of the motor and it will go faster. It will also draw more current. In life you get nothing for free.

Later dudes