Episode 4 of Motorheads kicks off with a charming scene where young Logan patiently instructs young Christian on the art of driving. As Christian blossoms into a seasoned pro, Logan takes pride in leading him to the junkyard to reclaim the legendary UNB10. Flashing forward to the present, Logan enthusiastically joins the group's brainstorming session aimed at revitalizing the UNB10.
Shifting scenes to school, Noah eagerly shows Harris an online video featuring his incredible shredding skills at the takeover. Initially believing it to be a testament to his prowess, Noah soon realizes it's merely a cruel joke at his expense. In auto shop class, excitement builds as new laptops arrive, and Curtis, bold but nervous, attempts to invite Cate out after class, only to be politely declined.
Undeterred, Curtis and Zac skip class and embark on an adventure to Pittsburgh. Meanwhile, Sam continues her exploration of Ironwood, revisiting familiar landmarks. At the skate house, she bumps into Darren, who mistakenly assumes their encounter marks their first date at the rink. Together, they embark on a nostalgic stroll around the town, reflecting on the changes that have shaped their hometown.
Elsewhere, Curtis finds himself in a pickle when his motorcycle engine stalls. Desperate, he calls on Ray for assistance, who sends Mike to rescue them and whisk them away to a street race organized among Ray's friends. At the lunchtable, Cate accepts Kiara's invitation to join her, Noah, Harris, and Alicia. Noah's car, having picked up odd noises after a race with Zac, catches everyone's attention. Cate offers her expertise, but Noah hesitates, doubting the suitability of Logan's seemingly outdated garage for his high-tech car. Kiara, however, insists, and Noah is left astounded by Cate's profound knowledge of automobiles. Despite his initial reluctance, Cate persists, offering to diagnose and repair the car at Logan's garage.
Meanwhile, Zac and Curtis immerse themselves in the street race, meeting more of Ray's influential friends. Nicknamed the "mayor" for orchestrating such events, Ray forms a bond with Zac and vows to help him hone his racing skills further.
Back at Ironwood, Harris finds himself ensnared in a cyberbullying nightmare, triggered by a video of his shredding exploits. During lunch, his eyes fall upon the perpetrator who uploaded the derogatory clip online, prompting Harris to challenge him to a race. Throughout the race, Harris and his adversary remain neck and neck, their skills evenly matched. As they approach a narrow bridge where only one car can pass, the rival realizes Harris isn't slowing down, threatening imminent collision. Sensing impending doom, he decides to yield, averting a potential disaster.
Elsewhere, Sam and Darren's tour progresses, now finding them engaging in a game of pool at a club. Darren draws parallels between their current circumstances and their high school days, reminiscing that he was the underdog akin to Zac. Harboring a secret admiration for Sam, despite her relationship with Christian, Darren reveals the rationale behind his bet with Christian. His conviction that Christian was unworthy of Sam led him to wager that if he won the race, Christian would relinquish Sam to someone more deserving.
Cate pitches an idea to Logan for upgrading the garage, seeking to revolutionize their venture. Meanwhile, Ray chauffeurs Zac and Curtis to his chop shop, with Zac seemingly seduced by the prospect of Ray mentoring him in racing. Curtis, however, cautions Zac against becoming too close to Ray, reminding him that if he wishes to pursue racing seriously, he has Logan, who has already groomed Christian into a champion.
Harris and Alicia share an intimate conversation, where Alicia expresses her feeling of insignificance to him. Harris opens up about contemplating steering off the bridge during the race, merely to feel alive, a notion he abandoned upon winning. Alicia ponders what might have transpired if Harris had lost, a question he cannot answer but reassures her that he wouldn't have taken such a drastic step if she were with him. Thus, Alicia holds immense value to him, even when he doubts his own worth.
Zac approaches Logan for racing lessons, but to his disappointment, Logan declines. As Sam and Darren conclude their tour, Logan visits Marcel, offering to escort him to school until his car is repaired. Returning to the garage, Curtis and Cate confess their mutual affection, with Cate sharing her ordeal of Noah's insult. Curtis confronts Noah, issuing a stern warning never to disrespect her again.
The episode concludes with Zac, rejected by Logan, seeking assistance from Ray.
