The next part of our “dirt education” will be focusing on dirt modifieds. If you are familiar with dirt racing, than you probably know what there are two common forms of dirt modifieds that exist in the sport. Again, like most forms of dirt racing, it all depends on your region. In this article, I will be breaking down both forms of dirt modifieds.

In this article, you will find

  • Define Dirt Modified
  • Two types of Dirt Modifieds
  • UMP/IMCA Style
    • Specifications
  • Northeast Dirt Modifieds
    • Specifications
  • Popular Dirt Modified Series
  • Major Dirt Modified Races

Helpful Links

Hey Google, Define Dirt Modified

A dirt modified is a race car specifically designed to run on dirt ovals. They are considered as an open-wheel style car because the front wheels are exposed. The rear axel and tires are mostly covered by fenders. If there was an open-wheel hybrid, this would be the car.

Types of Dirt Modifieds

When you examine the two common types of dirt modifieds, you would think that there is no way these cars share the same name. The most popular form of dirt modified racing is UMP/IMCA style cars. UMP and IMCA are just the sanctioning bodies, but that is what these cars are typically identified as. The other type of dirt modifieds are “Northeast” dirt modifieds. They get their name because they primarily exist in Northern Canada, New York, New Jersey and Delaware.

UMP/IMCA Style Dirt Modifieds

Photo via Nick Hoffman

UMP (United Midwestern Promoters) is one of the most popular sanctioning bodies for this style of dirt modified racing. Hence the name, these cars are very popular in the midwest and southern regions of the United States. The other sanctioning body, IMCA (International Motor Contest Association), has been supporting dirt modified racing since 1979.

The difference between the two sanctioning bodies is minimal, as the two have some different rule packages, but make it possible to run a dirt modified under both series with some minor changes to the car.

UMP/IMCA Specifications

While engine types and series rules can change the specifications, some common things you will find on these dirt modifieds include:

  • Any American made push-rod type engine will be permitted as long as the rear of the engine bell housing flange is mounted at least 72”-inches forward from the center of the rear axle.
  • Common Engines are 400-410 cubic inch Chevy small blocks that can produce 655-700 HP.
  • Aluminum blocks are not permitted with the exception of the CTC525 aluminum block
  • Fuel injection systems or electric fuel pumps will not be permitted
  • The maximum body width at the body’s widest part will be 72 inches. The minimum of width at the body’s narrowest part will be 53 inches. The top of the doors may have a maximum width of 67 inches. The bottom of the doors may have a maximum width of 68 inches. On the left side, the rear of the door may flare out six (6 inches) for tire clearance.
  • Car weight is 2400LBS with the driver inside

– DIRTcar UMP Modified Rules

Northeast Dirt Modifieds

Rick Sweeten Images

The “beasts of the Northeast” is what you might hear an announcer say when commentating a northeast dirt modified race. A Northeast dirt modified is also commonly referred to as a “big block” modified, even if the car does not have a big block under the hood. These cars historically have been run with a big block engine, but have migrated over to the small block and crate racing over the years.

A Super DIRTcar Big Block Modified will look something like this:

  • 467 max cubic inch big block engine
  • Produces over 800HP
  • Weighs 2500LBS with the driver in the car
  • The body width, when measured at any point along the body line from front-to-back will be a maximum of 68”-inches and a minimum of 64”-inches
  • The side door panel(s) will be a maximum of 86” inches and a minimum of 60”-inches in front of the centerline of the rear axle when measured along the top plane. The door(s), front door extensions and

– Super DIRTCAR Series

The Northeast Dirt Modifieds have the largest and most powerful engine in all of dirt racing. However, because of the weight of the car, they do not reach speeds that you will see in sprint car racing. These cars produce a lot more power than necessary sometimes, especially when they are running on slicked over surfaces.

Tracks in New York, Delaware and New Jersey offer Northeast style dirt modified racing with both 358 spec engines and 602 crate engines. These cars will often weigh about 2350lbs with the driver. In some series, teams are allowed to compete against the big blocks with a 358 spec small block engine. Depending on track conditions, the weight break can provide a competitive advantage over the big blocks.

Popular Dirt Modified Series

UMP/IMCA Style

Northeast Dirt Modifieds

Major Dirt Modified Races

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Published by Steve Thornton

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