Honda Shadow Aero 750

Mods and How-to's

Before you Mess with your Bike’s Exhaust

Submitted by Bama

The engine is a machine to make the bike perform in a certain manner. It is made up of various parts that all interact with each other. The sound of an engine is the way it is for a reason and it is not an accessory or a fashion statement.

If you want the bike to be a little louder then poke holes through the baffles. Anything beyond that will definitely affect the rest of the engine in an adverse way, offsetting the balance of the entire fuel/air/exhaust systems.

Freeflowing pipes can create an impressive amount of power increase as long as the rest of the systems are changed to match. If you change the exhaust you will need to change the intake side of the engine to maintain the proper amount of engine pressures. It’s like a triangle diagram. Three major components go into the selection of exhaust that eventually determine the volume and tone.

Volume of air, volume of fuel and volume of exhaust. The proper ratio will produce a certain amount of exhaust pressure. Too little back pressure and the valves tend to burn up. Too much back pressure and the whole engine gets constipated from fuel. The fuel gets into the oil system diluting its efficiency and the pistons/valves develop heavy carbon deposits that rob power.

Too much air and not enough fuel causes a lean condition. This can also be caused by opening up the exhaust. The lean condition is the one that burns valve edges and holes into the tops of pistons. Too little air makes for a rich condition. The same can happen by stopping up the exhaust pipes.

Screwing around with this stuff for the sake of a few decibels to sound cool isn’t really a good idea. Loud bikes are not impressive. Performance bikes that just happen to be loud are very impressive. They also run impressive.

Here’s your solution: Dump that big trashcan exhaust and buy a nice new set of aftermarket duals or a tunable 2 into 1 exhaust system. Buy yourself a Thunder Mfg. Hurricane or Tornado breather. Add a stage 2 or stage 3 Dynojet jet kit. Advance the timing 4 degrees by slotting the sensor plate. Go riding. Do all the mods at once.

The bike will have the exact volume you want and also have the tone that sounds great. The bike will actually have better mileage per tank, run better, accelerate better and be as good as it can be without any detrimental loss of engine life.

A good sounding engine is comprised of two qualities: volume and tone. A nice tone sounds good at any volume, quiet or loud enough to set off car alarms. A shitty sounding tone sounds even worse when it’s louder. Volume does NOT make the bike sound better, just louder. A crappy running bike is still a crappy running bike no matter how great it sounds in the bike night parking lot. Decide who it is you want to impress, then make the decision.

This website and it's contents are not affiliated with with Honda Motor Company, or any other group or organization. Performing the modifications listed within the website is done at your own risk. Developed and hosted by McLauthlin Technologies, LLC. Send questions, comments, or additions to