Volvo loses best WTCC result with Bjork excluded from Slovakia Ring

Bjork finished the first race in seventh in his manufacturer-backed S60 Polestar, then equalled Volvo's best finish in the modern era of the WTCC with fourth in the second, having completed a last-corner overtake on Honda's Norbert Michelisz.

But a post-race two inspection found that the metal in his engine's air restrictor had expanded significantly to deem it non-compliant with the regulations, with Bjork's car consequently struck from both race results.

Article 334 of the WTCC's TC1 technical regulations states: "The maximum internal diameter of the restrictor is 36mm, maintained for a minimum distance of 3mm measured downstream of a plane perpendicular to the rotational axis situated at a maximum of 50mm upstream of a plane passing through the most upstream extremities of the wheel blades.

"This diameter must be complied with, regardless of the temperature conditions."

Team-mate Fredrik Ekblom's car passed scrutineering and as a result moved up to ninth in the opening race classification, and eighth in the main race.

Polestar did not appeal the decision to excluded Bjork's S60.

"The temperature of the engine and air restrictor was considerably higher when measured after the second race in Slovakia compared to during the race," said Polestar's head of engine development Mattias Evensson.

"This means that there was no performance gain in the races, only the fact that we have not been able to test the expansion of the metal at these extreme temperatures that are only reached when stopping the car in parc ferme."

Bjork's exclusion is Polestar's third from WTCC sessions in the opening two rounds of the championship this year.

At Paul Ricard, Bjork qualified sixth only to have his times removed after his car failed a ride height test, while Ekblom was excluded from Slovakia Ring qualifying after he missed a weight control.