Toy cars have small wheels that need to travel in a straight line to gain sufficient speed to ascend and jump from a ramp. Long cardboard tubes like those that once held wrapping or butcher paper work well to keep smaller toy cars on a straight line of descent. Larger cars should be guided by tracks made by connecting rectangular pieces of cardboard wide enough for the wheelbase and 1 inch of upturned sidewall on either side. Use masking tape to connect your speed track to the floor and a raised surface like a chair or table. Test your track by placing a toy car at the beginning and releasing it. Observe the angle where the end of the track meets the floor and how it affects the way the car leaves the track. Adjust the angle to be less severe if it is causing cars to go off course.
Connect a cardboard ramp to the end of your speed tunnel for a super jump. Ramp pieces should be made using semi-rigid corrugated cardboard. Cut a piece of cardboard into a rectangle that is 10 inches long and twice as wide as the wheelbase of your car. Cut a notch in one end of the ramp piece that is the width of your descent ramp and bend down the flap that was created. Connect the two pieces at this juncture with masking tape to ensure a smooth transition. Tape straws lengthwise on both ascending edges of the ramp to guide cars to the edge. Use multiple stacked straws for cars with larger wheels. Set the open end of the ramp up on a stable, slightly raised surface like a couple hardback books. Secure the ramp's edge with tape and attempt your first run by releasing a car at the beginning of the speed track.
Now that the essential components of your toy car ramp are assembled, it is time to produce the best possible jump. Make adjustments to the angle of your descent track to produce more speed on jumps. Mark the distances of your jumps with small pieces of masking tape. Now try raising the angle of your ramp by placing additional hardback books under the edge. Do this one book at a time, again marking the changes in jump distance with tape. Write the number of hardback books used on that jump onto each piece of tape before placing them on the floor where the car first makes contact with the ground. Continue adding books until you find an optimum angle of rise for your ramp to produce maximum jump distance.