NASCAR '98 cheats and cheat codes for Playstation

Unlock EA Sports car
Highlight Kenny Wallace's car at the car selection screen in
exhibition mode, then hold the X - button and press Up, Down.

Unlock Pinnacle Trading Cards car
Highlight Bobby Labonte's car at the car selection screen in
exhibition mode, then hold the X button and press Up, Down.

Unlock turbo mode option
Hold Circle and press Up, Left, Down, Right on the options screen.
Go to the unlocked new option and increase the game's frame rate.

Enable Paintball mode
Pause the game play and bring up the race statistics screen.
Then, hold L1 + L2 + R1 + R2 + Triangle buttons on your controller
until the sound of an engine is heard. Go back to the game and push
Triangle to shoot paintballs at the other cars.

Faster car settings:
Go to the car setup screen then make the following adjustments.
Set the tire pressure to the maximum.
Set the wedge to the minimum
Set the rear spoiler to the minimum
Set the gear ratios to the maximum