Kenny tricked Spenny into believing that Kenny's mother, Tzafi, was dead. This was done to make Spenny go to a fake funeral miles away from the race track. When Spenny found out it was fake, he lost his mind and went totally bonkers.
It could be argued Spenny also cheated early on at the whiteboard, while making the rules. Kenny said, "no touching" and Spenny agreed he never wanted to touch Kenny. Kenny then stood in front of the whiteboard and Kenny touched him to move him, resulting in Kenny telling him he just lost. Spenny in his classic angry voice yelled, "during the race or before the race" then said, "I don't even know what I'm saying". It could be argued that Spenny cheated and lost the competition right there when he touched Kenny.
6th Nov 2006 / Season 3 Episode 04
Kenny tricked Spenny into believing that Kenny's mother was dead, so that Spenny would go to a fake funeral miles away from the race track. Spenny managed to drive back to the track and still beat Kenny.
Perhaps as revenge for being lied to about Tzafi's death and bringing food that he was yelled at by calling not kosher, in the Better Jew episode, Spenny makes Kenny do something very un jewish