The Frissbee KR3 started as a Lola T330 and featured a 5-litre Chevrolet V8 engine. It was first used by Horst Kroll's self-run Horst Kroll Racing team at the opening round of the 1984 Can-Am season, held at Mosport;^[2] he finished in fourth place.^[3] At Dallas, he finished eighth, and fifth of the full Can-Am entries,^[4] before finishing second at Brainerd,^[5] fifth at Lime Rock,^[6] second at Road Atlanta,^[7] and fourth at Trois-Rivières.^[8] The next round of the season was held again at Mosport; he went one better than the first race of the season and took the KR3 to third place.^[9] He finished the season with eighth at Sears Point,^[10] fourth at Riverside,^[11] and eighth in the final round of the season, held at Green Valley.^[12] Kroll finished the season in third place, with 119 points; 37 behind Jim Crawford, and 31 ahead of Kim Campbell.^[13]

Kroll used the KR3 again in 1985 and started the season with a win at Mosport.^[14] The next two rounds, both held at Lime Rock, were less successful; Kroll finished tenth overall, and fifth of the full Can-Am cars in the first race,^[15] before taking fourth overall, and second in class, in the second race, held two months later.^[16] The fourth race of the season was held again at Mosport; Kroll returned to the podium, taking second place.^[17] The penultimate race of the season was held at St. Louis International Raceway, where Kroll again finished second.^[18] He finished the season by finishing eleventh overall, and sixth in class, at the St. Petersburg Grand Prix.^[19] Kroll finished second in the Driver's championship, with 71 points; ten behind Rick Miaskiewicz in a similar Frissbee GR3 and 19 ahead of Lou Sell in a 2-litre March 832.^[20]

For 1986, the Can-Am series saw a partial split; a new Canadian American Thundercars Championship (CAT) was formed, and four races were shared between the two, with a fifth race being held as part of the latter series.^[21] Kroll started the 1986 season in the same way he had started the 1985 season; by winning the opening race at Mosport in his Frissbee KR3.^[22] Kroll followed this with fourth overall, second in the O2L class at Summit Point,^[23] and a pair of second places, at St. Louis and Mosport.^[24][25] As a result, Kroll won the Can-Am championship, with 64 points; 11 points more than his closest rival, Bill Tempero, who drove a March 84C.^[21] Kroll finished the CAT season with sixth place at Hallett,^[26] having taken tenth in the first race,^[27] and fourth in the second.^[28] This was enough to also secure him the CAT title, beating Tempero by ten points.^[21]

In 1987, the Can-Am series folded, and the CAT series took over.^[29] Kroll continued to use the KR3, but retired after four laps from the first race of the season, held at Willow Springs,^[30] before finishing third at the second race;^[31] this was enough to secure a seventh place at the meeting.^[32] He then took third at Hallett and Milwaukee,^[33][34] before finishing fourth at Sanair.^[35] Kroll finished the season by taking eighth at both Pueblo and Phoenix;^[36][37] his 65 points were enough for him to take third in the Driver's championship once again.^[29] He finished 27 points behind Al Lamb in a similar Frissbee GR2, and three ahead of Buddy Lazier in a March 85C.^[29] The CAT series was replaced by the American Indycar Series in 1988,^[29] and the KR3 was not used again.^[38]