Kaufmann stresses that durability problems with exhaust systems might be solved by using oxygen acetylene welding. "It disperses the heat over a wider area, so when you go through heat cycling, you're not going to have as many points in the exhaust system that electronic welding a lot of time creates; places that don't take the cycling well and cause fractures," says Kaufmann.
"Most of the fractures you see in exhaust systems on race cars are right at weld points. The reason for that is the particular part where the weld is located got so hot and was dispersed over such a small area with an electronic weld that it becomes almost like a stress riser, only it's basically a thermokenetic hot spot. It's not necessarily bad engineering for them to consider using oxygen acetylene for welding their exhaust system because of the tremendous heat cycles that race cars go through."
Often overlooked, according to Kaufmann, is an exhaust's support system. "You really can't over-support it," he says. A system lacking adequate support will often develop fractures, leading to leaks that might reach the driver's compartment and potentially to loss of power.
Since an exhaust system is closer to the ground than any part of a stock car, other than the tires, clearance issues sometimes arise. But Kaufmann says flat tubing may help alleviate potential problems. "Just make sure you do the mathematics to see that the square tubing ends up being the same amount of area as the round tubing," he says.
Perhaps the key underlying concept to maximizing the performance of your exhaust system is simply to give it proper respect.
"The lesson I can tell people is you can't overanalyze any single part, and you can't do too much as far as maintenance," says Kaufmann. "An exhaust system should be right in the nuts and bolts check from race to race."