Image: The MINT 400

It’s not every day that you find a vehicle that made as many moves forward for off-road racing as Mickey Thompson’s Challenger IV. Now nearly 40 years after it was originally built, we take a look at this magnificent ride for this week’s Vintage Monday.

Image: Autosport Forum

Built in 1977 by the late Mickey Thompson (the racer and mechanical genius who started Mickey Thompson Performance Tires and Wheels) and his then crew chief John House, the Challenger IV brought forth a new strategy in off-road racing, first debuting at the 1978 Mexicali 300.

Instead of using VW-powered buggies, which was the popular choice in the 70s, Thompson opted to build a buggy powered by a front-mounted Chevrolet V8 and much greater wheel travel than the competition. This is how the Challenger IV was born.

The first step to implementing this new racing configuration was getting the monster engine right. For his rig, Thompson used a 700hp V8 and to help stabilize the car at high speeds with all that weight up front, he fitted it with a huge rear wing.

Next was the increased wheel travel, of which Thompson achieved 15 inches of wheel travel in the front and 18 inches of wheel travel in the rear, nearly double that of his rivals at the time.

Giving the Challenger IV its incredible wheel travel was an A-arm front suspension complete with custom Thompson-made dual gas shocks fitted with cooling fins and additional floating torsion bars.

In the rear, the incredible wheel travel was engineered thanks to a live axle, matched up with dual coilovers and Thompson’s custom-built 41-inch long shocks.

Image: Bruce Parrish/ Off Road Action

Though the high-horsepower/increased wheel travel idea was a great one, and certainly impacted the off-road racing scene since, the Challenger IV was not an immediate threat to fellow competitor’s buggies.

This is because Thompson had a hard time not going full throttle and, though he would lead most of the races he entered with the Challenger IV, Thompson would eventually tear up the equipment on the rig to the point where it couldn’t complete the race.

Still, Thompson proved that big engines matched with custom suspension systems could be the way of the future and of winning races. Now days, you would be hard-pressed to find very many competitive off-road rigs fitted with anything smaller than a V8 or not featuring long travel multiple shock systems.

The Challenger IV was raced from 1977 through the 1980 MINT 400, after which Thompson introduced his next-generation race rig, called the Challenger V, to the off-road community.

Mickey Thompson racing the Challenger IV during the 1978 Mexicali 300. Image: Roger Caddell/ Off Road Action

Still in Thompson’s possession when he and his wife were murdered at their Bradbury, California home in March of 1988, the Challenger IV was passed down to Thompson’s daughter, who kept it in her shop in Oregon for over 20 years.

Just recently, a man named Rory Ward purchased the Challenger IV and has been working to restore the vintage racer ever since. In its current form, the Challenger IV features a 383ci SBC, a two-speed Power Glide transmission, retro shocks built by King, and a magnesium Dana 60 rearend built by Sandy Cone.

A truly innovative off-road race rig for its time, Mickey Thompson’s Challenger IV will forever be known for the strides it helped make in the off-road racing world. Now under Ward’s care, we hope to see the rig once again tackle some of the country’s toughest races and hold a lead like it once did back when Thompson was behind the wheel.