When it comes to high-performance exhaust systems, adversity can face racers at the most inopportune times. We asked our contacts about some of the most common challenges they’ve come across, and the advice they’d offer to help resolve these issues beforehand.
“Most recently, sound levels have been a problem area for many racers,” said Vince Roman of Burns Stainless, Costa Mesa, California. “As homes are built closer and closer to race tracks, muffler rules are being imposed. Unfortunately, since the conditions at tracks vary by local issues, the rules are not uniform and can cause racers confusion. Best thing for racers to do is investigate the sound restrictions at the various tracks that they race,” he said, adding Burns Stainless staffs experts that can help develop a strategy to meet track requirements and improve performance.
Gary Donahoe of Coast Fabrication in Huntington Beach, California, explained, “It is important to have a full understanding of all regulations prior to designing the exhaust system. It is very important to make certain there is sufficient room to accommodate whatever muffling devices are needed.”
Glenn Myers of Coleman Machine in Menominee, Michigan, told us racers should consider how a muffler is mounted when they need to meet a maximum decibel rule.
“In some applications where it’s legal, it may be necessary to dump the exhaust down under the rear of the car in front of the axle and away from where the decibel reading is taken,” he said. “This will drastically reduce the decibel reading by spreading the exhaust out across the flat surface of the track. If it is required to run the exhaust out the side of the car, it is recommended that the exhaust pipe also be directed downward toward the ground as much as possible to help break up decibels.”
Myers further stressed the importance of securely mounting the muffler. “The parts must be securely clamped or bolted in place,” he said. “The exhaust system is subject to high vibrations and severe temperature changes, which can cause the clamps and brackets to loosen. All clamps, brackets and bolting flanges must be checked for tightness before each race. If the exhaust system comes loose during a long race, the driver may be subject to deadly carbon monoxide poisoning and not realize it until it’s too late.”
Ground clearance is yet another potential trouble spot for racers’ exhaust systems, said Jehan Tetango of Holley Performance Products, Bowling Green, Kentucky, adding that Holley’s Hooker Blackheart products feature a high-tuck design and provide ample ground clearance.
Leakage, especially on fuel-injected vehicles, can present problems as well, according to Chris Hill of SPD, Rancho Cordova, California. “You need to be able to get things sealed up. There are times where you can’t use slip-on everything—every collector slipping on. Sometimes you have to weld everything up and still plan for it that way, especially when you get around O2s and things like that; you can’t have leakage going on,” Hill said. “We spend a lot of time trying to make sure that even when we’re using slip collectors, the tube finishes at the bottom of the seat and the slip joint on the collectors are all the same. We spend a lot of time on details.”
Finally, David Borla of Borla Performance in Oxnard, California, summed up what he considered to be a fundamental challenge for the category—namely, informing racers that they can indeed be both quiet and fast by utilizing the right exhaust systems. “We’ve really been able to dispel the myth that you have to slow yourself down to be quiet,” he said.