The difference between asphalt and dirt car

[77v8stock]

Im always hearing folks talking about new cars coming to the dirt track that were previously asphalt cars. What is the significant difference in the set up of the two? What mods need to be made to an asphalt car to run it on dirt? I would think the setup would be similar but just dont know. Any information is appreciated.

Thanks
77ministock

[TROUBLE]

An asphalt car is set up to use the chassis to force the tires to handle and grip the track. Such as a soft spring - big bar set up. The platform is very rigid and is not very forgiving. The main thing that people think of when they say paved track car is that it has spring adjusters built into the chassis and even a track bar that is adjustable.

Where as a dirt track car - usually the track rules say no jack screws and nothing adjustable. In a dirt car you use a stiff spring and shocks to make the chassis handle. Most people take the sway bars out and want the chassis to sway in the turns. Some chassis designers actually want chassis flex in a dirt track car. In a dirt track car - you want to go into the turns as hard as you can and make the tires slide and grip the track and sling you out of the turns.

If you did that on a paved track you would either wreck or else abuse the tires so bad that you wouldn't make it more than a few laps before they would blow out.

Paved track tires are hard because they have to be to stand up to the abuse of a 3100 lbs car and all the g force and side loading that the tires have to take lap after lap.

Dirt track cars have very soft tires, the rubber in the tires actuall try to grip the dirt / clay on the track. The sidewalls in the tires have much more flex than does the paved track tires.

[jworacing]

And you don't need to wash an asphalt care as much!