Traditionally, Big-Block Modifieds have raced with three-link, torsion-bar rear suspensions. Recently, many teams started moving toward using coil springs in the rear. Car owner Ted Barcomb, of Rochester, New York, thought about taking it one step further. The Dirt Late Models and Modifieds commonly found outside of the Northeast use four-bar rear suspensions. Could that be the next step in the evolution of Big-Block Modifieds?
What’s Old is New Again
Barcomb’s idea is not new. Troyer Race Cars offered a four-bar rear suspension during the late 1990s to early 2000s. “The four-bar setup fell out of favor because it was finicky and hard to drive,” said Barcomb. “We really didn’t know what we were doing.”
These days the dirt racing world has learned more about the cars they race. This is thanks to pull-down rigs, data acquisition, Spring Smasher and Gale Force machines, and other setup equipment that helps measure the car’s setup in its dynamic state — the attitude it’s in when on the track, as opposed to its static state when it sits in the shop. With this information, setups have become more precise. The team hoped the level of precision now available could match what the four-bar installation requires.
“That’s why Big-Blocks have run the three-link, torsion-bar setup — it gives you a big sweet spot,” said TJT Motorsports/Protrac Racing Shocks’ Todd Thompson, who serves as the team’s shock specialist. “With the four-bar setup, we are on the knife’s edge.”
Barcomb felt Troyer’s latest chassis, the TD4, also provided a good opportunity to try the four-bar setup. “The TD4 was designed for side-bite and turning,” said Barcomb. “Years ago, the four-link setups were always tight, and I felt like this chassis would alleviate that condition.”
Why It Has Potential
“The biggest thing is the capacity for more rear steer,” said Thompson. “The standard chassis everybody built for years was a three-link suspension, with the option to have a spring rod on the right rear to let the rearend move forward on that side. A Late Model always moved the left rear forward.”
“In a Late Model, it is tied to the droop of the left rear. As the Late Model enters the corner, the left rear extends, and the wheelbase gets shorter on the left side, which helps to turn the car. The Big-Blocks did the exact opposite with the right rear moving.”
Thompson said they had reasons for doing that with the Big-Block Modifieds. “The spring rod on the right rear was the major adjustment,” said Thompson. “How much rate you had preloaded into it determined on how tight or loose the cars were. Plus, the torsion-bar setup didn’t want much rear steer.”
Coil springs also changed how the suspensions worked. “There is a lot more movement in a rearend with a coil-spring setup, and they are more like a Late Model now,” Thompson said.
Converting a Mod to a Late Model
In 2018, Barcomb debuted the setup with driver Rob Bellinger, 30, of Cicero, New York. It didn’t go smoothly, at first.
“What limited us last year was how the Panhard bar was built and the rearend mounted,” Thompson said. “I took a grinder and a Sawzall and got it close to what it needed, to move freely. Wehrs Machine & Racing Products, a manufacturer of Panhard bars (aka J-bars), took what we had done and machined us parts this year. We still had problems ripping the pinion mount. There is a lot of force on that compared to a Late Model. A Big-Block runs a lot of rear weight percentage and high roll centers.”
Bellinger had to get used to how the four-bar setup drove on the track. “It feels like how a Late Model looks,” said Bellinger. “The way it stands itself up off the left rear — it feels like it has quite a bit of drive.”
This made it advantageous in certain conditions — and not so much in others. “It was definitely better when the track had blown off — when it was dry, slippery,” Bellinger said. “It would react a little too quick, on the throttle and on the brake, when it was heavy.”
Unlike a Late Model, rules mandate one-piece front axles on the Big-Block Modifieds. This provides a challenge.
“Our biggest problem is that [the four-bar setup] overpowered the front end,” Bellinger said. “We’re still on a [one-piece] front axle, where a Late Model has an independent front suspension.”
Thompson also struggled working with the front end. “We tried Late Model front shock combinations on the Big-Block,” Thompson said. “It didn’t work.”
Another difference between a Late Model and Modified relates to the lack of bodywork upfront. “We don’t have a big, flat nose catching a lot of air,” Bellinger said. “Our car compared to a Late Model, between the way [the front suspensions are] designed and the way the bodies are, they’re definitely lacking front grip.”
Nevertheless, despite running a limited schedule, Bellinger raced the four-bar car to victory lane in June at New York’s Brewerton Speedway. “We were good with it quite a few times,” Bellinger said. “We were just not overly consistent. There is something there to make our cars better. It’s hard to figure it out because we don’t race that much. We ran maybe 20 times this year with the Big-Block.”
Super DIRT Week, held last week at New York’s Oswego Speedway, epitomized how the team has done with the four-bar experiment. They missed on their initial setup, qualified poorly, and found themselves in the last-chance qualifier. However, then they shined.
“We started 10th in the last-chance qualifier, and had to get to fourth to make the show,” said Barcomb. “Rob had the lead by lap 12 and won it. It was such a relief — to not only get into the show but to have that good of a car. We felt we had a good chance for a strong run on Sunday.”
However, in the 200-lap feature, their hopes came to a crashing halt in the second half of the race, when Bellinger tried to avoid a wreck and wound up totaling the car.
Next year, Barcomb said he plans to scale back his schedule. With even fewer races on the agenda, he anticipates returning to a more conventional setup. However, his efforts may not have been for naught. It has created interest in the four-bar suspension, and others may pick up where Barcomb left off.