Exhaust Dynamics

Exhaust Dynamics



Are you frustrated having to choose between quality sound and power? The answer you and countless others have been looking for has been answered with the introduction of Thunder Monster baffles.

The latest innovations from Big City Thunder are our patented and trademarked exhaust enhancing baffles that deliver not only a deeper sound but also improved performance over a standard baffle or unbaffled pipes. While standard baffles deal somewhat with the issues of exhaust flow, back pressure, sonic and thermal pulses, etc. they generally return less than desirable results, particularly in the area of sound. While removing or cutting the baffles in length may seem to produce more sound it is usually not a deep, crisp, sound but a higher, blatty, brassy sound. Also when baffles are removed or cut down the midrange performance and torque can suffer. Cutting the baffles can also create a throttle hesitation which is a symptom of fuel standoff. Trying to compensate by tuning the carburetor /mapping the fuel injection, or adding more cubic inches will not remedy these issues.

Our original Thunder Monster baffles are designed to deal with the sonic and thermal pulses, deliver the correct amount of back pressure, and act as a superior anti reversion device. They also create a deep, clear, hot rod, throaty rumble. Our new QQ Thunder Monster baffles deliver a slightly quieter more subtle sound than our Original Thunder Monster baffles with a deeper, throatier tone.

Our Original Thunder Monster baffles are designed to fit exhaust pipes with an inside diameter of 1 5/8", 1 3/4", 1 7/8", 2", or 2 1/8" that have removable baffles, straight pipes
with no baffles, and Screamin' Eagle II Slip Fit Mufflers with removable baffles that measure 2 7/8" diameter x 11 ¼" in length. We also offer our patented 1 5/8" Thunder Monster baffles for head pipe installations for gutted mufflers or mufflers with a removable baffle.

Our new QQ Thunder Monster baffles are available for pipes with an inside diameter of 1 5/8", 1 3/4", 1 7/8", 2" and 2 1/8". Additionally we now have Thunder Monster baffles for certain Screamin' Eagle Street Performance Mufflers. For Bagger applications your Screamin Eagle Street Performance baffle should measure 3 3/8" diameter by approx 26 1/4" in length. For Softail applications (with minor modifications these will fit Sportster and Dyna applications as well) your Screamin' Eagle Street Performance baffle should measure 3 1/8" diameter by approx 17 3/4" in length. (Please visit our Products & Fit page for more information.)

In most applications Big City Thunder products install in minutes, provided your pipes have existing holes in the proper location. Drilling a new hole takes a little longer.

Our products are designed, tested and produced with uncompromising quality to provide superb sound and wicked midrange power in a bolt-in product. Independent dyno tests resulted in 12 HP and 14 ft. lbs more torque than a straight pipe with no baffle. We're talking torque power, not talk power! When tests were run replacing standard baffles with no other modifications, there was an increase in power and the sound quality was substantial. In addition to more power and torque, Big City Thunder products normally eliminate throttle hesitation associated with baffle removal and reduced the RPM drop when shifting gears. If you have cut your baffles and are not pleased with the results, our Original Thunder Monster baffles will deliver a clearer, crisper and deeper, hot rod sound with improved performance. Our new QQ Thunder Monster baffles are designed to deliver improved performance as well as a more subtle deeper tone to the exhaust note.

More good news. Big City Thunder Exhaust Products are available for both American and Metric bikes and certain automotive applications. This is an opportunity to get serious sound and power at affordable prices. PLEASE NOTE: Before contacting us, please measure all of the following:

  1. The outside diameter of your pipes with any tip or end cap removed (Do Not measure the heat shields).
  2. The inside diameter of your pipes
  3. The outside diameter of your baffles, if you have one

Please be sure to provide that information in your e-mail or when you call.

Our Mission

Big City Thunder is dedicated to providing precision engineered American made products of uncompromising quality to the motorcycle industry.

To remain the world leader in value and performance.

Customer satisfaction is the passion driving our success.