What to look for in a car?

Borrow your part's from a fast car..or modify a fast stock car...fast is fast. You can make a slow car faster but you can make a fast car faster.

Welcome MMD,

Speed with these cars comes down to a few simple things, really. You want nickel-plated axles...from the Faster than Ever cars, hence fte... or the Color Changer cars also have nickel coated axles. Personally, I like the original, 2005-06 fte cars.

Then, you want wheels that run true...in other words, they don't wobble. They don't have to be fte wheels, but ftes are a nice light wheel.

Next, you want weight. Since this is gravity racing, you want your car to be right on the weight limit for the race.

And lastly, your vehicle should be as long as possible. The longer a vehicle is, the longer it is on the hill, getting that push from gravity. This is also why I've been setting length restictions on my races...to keep them close.

So, that's about it...oh, and you'll want to use dry graphite on your axles. That's about all there really is to it...finding speed from there is all in the tiny details.

I agree with all the above, ... if you google pinewood derby speed secrets.... it all transfers to these smaller cars

You also learn as you go, with each build you have the chance to discover a niche...a little tweak that may pay off with more speed. Also, you hone your modifying abilities with each build...but sometimes you just build a dud even following modifying techniques to the letter. I feel like I'm better now than when I started about a year ago...I was a purist and had never drilled the rivets...I also had boxes of mediocre and slow cars lying around. So, if you want some raw material to practice the craft on...PM your address and I'll send you a dozen cars to start your own boneyard.

Here's a video that explains the physics of gravity racing...kind of a fun video too. It uses Pinewood Derby as the example but same stuff applies here.

As the others said, weight is a big key, so look for cars with a metal chassis AND a metal body. Or make a car that has a metal top and a metal bottom. Most of the cars on the pegs come as one or the other...at least the $1 variety. The top shelf $3+ cars are usually metal/metal but I never bother (they also usually have rubber wheels). But it's more fun to make a car with what you need. BTW, avoid the rubber wheels.

In general, if a car has a plastic body it will have a metal chassis, and vice versa. Remember, since we're building cars here, you don't need a matched set of body and chassis. Sure, it'll help but I've been plenty fast cars that take chassis from one casting and a body from another.