What Does Your Exhaust Say About You? How to read Mid America Motorworks IAC Exhaust Rating Chart

Decibel - 1. The decibel (dB) is a logarithmic unit used to express the ratio between two values of a physical quantity, often power or intensity. 2. The decibel (dB) is used to measure sound level, but it is also widely used in electronics, signals and communication. The dB is a logarithmic way of describing a ratio. The ratio may be power, sound pressure, voltage or intensity, or several other things.

Decoding The IAC Exhaust Rating Chart

What is an IAC Chart?

In 2006 the variety of replacement Corvette exhaust systems available to shoppers had grown well beyond a simple choice. Enthusiasts had to look past the visible tip design, size, and finish treatment. The sound of the exhaust had become the most critical consideration. In order to graphically quantify the sound level of this variety of products, the IAC Exhaust Rating Chart was born.

What does IAC stand for?

IAC is an acronym for the 3 points of engine operation the comparison would encompass: Idle, Acceleration and Cruise

Who created the IAC chart?

The IAC Chart is a trademarked system developed by the experts at Mid America Motorworks. Our Research and Development team created the chart based on years of experience installing exhaust and listening to the tones during the typical driving experience.

How do you read the IAC chart?

Mid America Motorworks IAC Chart is based on a comparison of the sound volume level of the original stock Corvette exhaust of a particular model. Each point of engine operation is rated on a scale of 1 to 3 for sound intensity.

What do the numbers mean?

A rating of 1 is slightly louder than stock. A rating of 2 is noticeably louder than stock. A rating of 3 is aggressively loud.

How do I find the exhaust I want using the IAC chart?

One of the defining characteristics of most Corvette owners is an independent spirit with unique individual expectations. The IAC Chart speaks only to the sound level element of the selection process. Use the evaluation to zero in toward the sound level that you feel would best suit your personality and driving habits. Hint: the loudest exhaust may not be the best choice for a car that is used for long distance touring, etc.

How accurate is the IAC chart?

The nature of such a scale has an element of personal judgment involved. We utilize a simple db meter in a controlled environment to establish a scientific baseline. Then Mike and a panel of other owners among our staff team up to score each variation based on personal tastes. Decisions are made factoring in more than 40 years of customer comments, owner feedback and general discussion.