TORRINGTON – Valley Motor Sports held its second Thunder in the Valley mud races this past weekend and despite the new competition, the truck teching remained the same.
Michael Cearns has been the authority when it comes to what class a truck goes in for three years. He is the tech guy, testing each truck to determine what class that truck can compete in, for all of the races held in Torrington.
During mud drags, there are five classes, while there are four classes for mud bogs. During the mud drags, the major deciding factor between classes in how big a motor is and how much of a vacuum it creates. In mud bogs, the tire size is one of the main factors separating the classes.
“We don’t want somebody that’s got a big motor, that thinks they need to run in the stock class,” Cearns said about classes tightening the competition. “That’s just not fair, so that’s why there are all the rules.”
The lowest class during mud drags is stock, where the truck needs to be able to be driven on the street every day. The sportsman class is similar to the stock class, but no license plate or registration is needed for the truck. There is also an engine size limit (less than 400-cubic-inches) and a vacuum regulation (17 inches of engine manifold vacuum at 1,000 RPMs for 30 seconds).

The engine size limit (468 CI) and vacuum rule (13 inches) are adjusted for the super stock class. Also in the super stock class, everything needs to be corporate matching, which means the main components of the truck must all come from the same company (i.e. Chevrolet or Dodge). The corporate matching rule carries into the pro-stock class, but there is no testing done on the trucks in that class.
The top class, the pro-mods, has limited restrictions. According to Cearns, “anything goes.” No trucks in the pro-mod class can have blowers or nitrous and everything needs to be naturally aspirated.
Cearns checks each truck in the pits before that truck is allowed on the track. He has the final say with which class a truck goes into.
“I just stick to the vacuum numbers and everything and what it tells me to do,” Cearns said. “Most people don’t argue about it. If I say that’s where they’re going to go, then that’s where they’re going.”
Although it is not possible to race down in class, it is an option to race in a class higher than the one you qualify for in order to get more racing in. Cearns said that it is uncommon for a racer to change classes during the middle of the race season, but during the offseason, some competitors alter their trucks and race in a different class starting with the new season.
For the mud bogs, tire size is a major check off. In the stock class, tires up to 34 inches are allowed. The sportsman class allows tires 34-38.5 inches, while the modified class allows tires 39.5 inches and above. The open class accepts any tires.
Although Valley Motor Sports’ rules are set, they do not match rules from around the region. Cearns said that Colorado and Western Wyoming, for example, each have their own set of rules they abide by, and those rules do not match the local rules.
In a sport that often involves weekend road trips around the area, Cearns said matching rules across the board would help involvement because people from the other regions would know exactly where they stand in local competition. He sees a change the rules in the future to allow level competition.
The local action this past weekend was the second of four mud races that Valley Motor Sports will host this summer. They return to the dirt Aug. 5 and again Aug. 19-20.