Automotive Exhaust Analysis

Cars are becoming increasingly complicated to meet new emissions and fuel economy standards!  As a result, increasing performance and customizing cars is now more complicated than in years past.  Notably, when a new model with new features is introduced, the aftermarket requires time to adapt and produce suitable products.  In this project, we extensively analyzed the entire exhaust system and vehicle to solve problems created by the installation of an aftermarket exhaust that was marketed as "Drone free" for the same model of car.  Thorough investigation revealed that the companies R&D car was a manual transmission, rather than an automatic, which our customer had.  The automatic transmission equipped car has different gear ratios than the manual transmission version, putting the engine at a different RPM and load, under which conditions a "Drone free" exhaust developed for the same engine, but with a manual transmission, simply did not work.  We discovered excruciatingly high noise levels during low RPM low load driving conditions when cylinder deactivation was active, and the V8 was firing on only 6 cylinders.  

Utilizing the laws of physics and readily available audio analysis apps and equipment, we were successful in reducing the "drone" by over 60%!!!  This allowed the customer to retain the exhaust and increased performance and sound that he wanted, without the annoyance and hearing loss associated with resonant frequencies of various car parts matching the frequency generated in the exhaust system.  The application of dynamat, a sound deadening material that also adds weight to the car, was successfully minimized by designing j-pipes in the correct length that the soundwaves would travel down the pipe and bounce back at the right time and speed to cancel other sound waves and alter the resonant frequency of the exhaust system.