Famicom Grand Prix F1 Race/Time trial overview

Time trial mode
Time trial mode is a chance for you to race on an empty track by yourself, and see just how well you can perform on six different tracks. Each track has a particular feature which it emphasizes. There are no rules, and you're free to take the track any way you like.

Before you begin, you can choose from the following settings:
 * Players: Between one and four players can race against the clock, with each player's final time results appearing at the end for comparison. Each player races alone, one at a time, using the first-player control pad.
 * Laps: You may opt to race around the track any where from one to nine times. Each player must complete the specified number of laps before a player's turn is considered over and the next player may race.
 * Circuit: Players may choose from among six different tracks to race on. None of these tracks are featured in the Grand Prix portion of the game, but they contain similar features.
 * Turbo: If you choose to race with a Non-Turbo car, you will drive the equivalent of a Non-Turbo 1000 PS Engine car. If you choose to race with a Turbo car, you will drive the equivalent of a Turbo 1200 PS Engine car. (see the Secret Code section below).

Secret Code
To select the specific car that you would like to drive, go to the time trial settings menu (pictured above), pick up the controller plugged into the second-player port, and press. This will bring up a screen showing one of the 24 cars. You can cycle through the cars by pressing or  on the first-player control pad, and press  to select a car. When you select one, note whether it is a Turbo or Non-Turbo engine. In order to use the desired car, you Turbo setting must match the choice of your selection.