It's a "Vacation" for a whole new generation when Christina Applegate and Ed Helms hit the highway in a brand-new, Griswold family road-trip adventure.

And even though there are cameos from Clark (Chevy Chase) and Ellen (Beverly D'Angelo), who were the stars of the original "National Lampoon's Vacation," this movie isn't a remake or a sequel. In the 2015 film,  the Griswold family is comprised of now grown-up son Rusty (Ed Helms), his wife Debby (Applegate) and their two sons, James (Skyler Gisondo) and Kevin (Steele Stebbins).

Although in the new one, Rusty is determined to revisit one of his favorite vacation memories -- the Walley World theme park from the 1983 film.

What wasn't funny for the former "Married With Children" star Applegate was the scene where her family gets stuck, hanging upside down, on a roller coaster. It was way more strenuous that she suspected it was going to be when she read the description in the script.

"Hanging upside down is not something I ever need to do again. I thought that lights out were going to happen to me. I know it’s not dangerous, but it was not good for me. I didn't enjoy that," says Applegate, who is seven years out from her breast cancer diagnosis and feeling "good."

While the majority of "Vacation" was shot in and around Atlanta, when it came time for the Griswolds to go white water rafting, the action took place at a facility in South Carolina.

"They had guys in wetsuits and rescue gear all down the thing because if you did fall out of the boat, you were gone, and you could drown," Applegate says. "So there was an element of fear for me there, and when we were in that boat and the water would come and push it down, you really felt...I mean, a couple times I almost fell out."

As an only child raised by a single mom, Applegate didn't take family road trips. "We didn't really do stuff like that, my mom and me. We struggled a lot, but we did go to Tijuana once in a car. That’s it. That’s all I got for you. We went to Tijuana."

Applegate also got a big chuckle out of working with her movie sons Gisondo and Stebbins. "They made me laugh really hard. So any time we were doing scenes with them, they tickled me," she says. The adds, "I’m a child of the ‘70s. You know what I mean? I was saying worse stuff when I was five than they were saying in this movie."

New Line Cinema's "Vacation," written and directed by Jonathan Goldstein & John Francis Daley based on characters created by John Hughes, opens in theaters on Wednesday, July 29.