You can see this act on TV'S WHACKED OUT SPORTS. The stunt is the DOOMS DAY CHAIR, performed at the OSWEGO SPEEDWAY
Watch as Captain Explosion kneeling in the DOOMS DAY CHAIR explodes the chair into little pieces. An explosive charge was placed about 18 inches from his head which was ignited.
The explosion can be seen in the (above) two pictures with a massive cloud of smoke from the exploding DOOMS DAY CHAIR.
The track safety crew helps Captain Explosion come to after the blast.