We’re four installments in, and the Grassroots Motorsports Club Spec Mustang has finally hit the track at a Tire Rack SCCA Time Attack Challenge weekend.

Let’s back up.

In a multi-part video series, Grassroots Motorsports is following along as GRM’s Video Editor Chris Tropea, under the watchful eye of GRM’s Tech Editor JG Pasterjak, preps an S197 Ford Mustang for SCCA’s Club Spec class, with the ultimate goal of making it to the Oct. 23-25, 2026, Tire Rack SCCA Time Attack National Championship at Eagles Canyon in Decatur, TX, and (hopefully) claiming a spot on the podium.

Club Spec is SCCA’s build once, compete everywhere series of classes, where one set of rules span SCCA Autocross and Time Attack, allowing someone to own a car that’s not only drivable on the street, but also competitive in class. Club Spec currently has classes for the NC MX-5s and early S197 Mustang GTs, with 718 Porsche Caymans and Boxters on the way in 2027.

GRM’s video series began with an introduction, then jumped into interior mods followed by a differential install. With much of the build complete, part four in the series takes the car to Carolina Motorsports Park (CMP) for the June edition of the Tire Rack SCCA Time Attack Challenge, where Tropea co-drove with Pasterjak. This was Tropea’s first time at CMP and his first time lapping a racetrack for a time; Pasterjak, meanwhile, hadn’t been to this particular track for 20 years. Needless to say, there was a learning curve.

There were also lessons when it came to the car. They resolved a fueling issue early on, and also discovered the car’s cooling system could use some beefing up.

How did the car and drivers do? Check out the video to find out.

Image courtesy Grassroots Motorsports YouTube Channel