Unwrapping the Mystery of Exhaust Wrap
There was a time when you only saw exhaust wrap on performance bikes. More and more, the process is becoming a moto-fashion statement. So what is the actual purpose of wrapping heat tape on exhaust headers and pipes? What are the benefits and possible down-sides? Here is the tale of the tape.
Exhaust heat wrap can be seen on cruisers, customs, rat-bikes, and sport-bikes. Aficionados say the wrap gives their bikes a retro, performance-specific look. The wrap does seem to accent most bobbers and rat choppers well. Wrapped headers on naked and half-faired sport bikes offer an aggressive industrial look. Maybe the best fit for the look is on retro café racers.
There was a time when heat wrap contained asbestos. Obviously, with what we know about that substance and its health risks, it is no longer used.
The most common material for the newer wraps is a dense fiberglass weave. The weave is durable, flameproof and insulative. It is also becoming more common to see wraps that are, in part, metallic weaves.
In addition to the base material of the weave, many wraps incorporate natural materials such as ground lava rock and ceramic.
The wrap is wound around the desired pipe much like wrapping a grip on a tennis racquet. The ends are affixed through various methods including heat resistant ties, clamps, and high-temp tape.
All of the benefits of exhaust wrap revolve around the material’s heat-controlling properties. The most obvious benefit is that fact that less radiant heat makes it to the rider’s legs or the bikes components and body-work. The wrap serves as a thermal blanket that directs more of the heat out of the exhaust outlet rather than the sides of the pipe.
Though external heat control is the primary benefit, there is also a potential performance benefit. Hotter exhaust gasses (as created by the insulation of the wrap) are less dense. Thus, the exhaust “scavenging” can be more effective. In effect, intake and exhaust gasses are pulled more quickly through the engine which increases performance.
Exhaust wrapping is not without its risks. First, the higher exhaust exit temperatures can lean out the fuel mixture of an engine – sometimes severely. An overly lean situation can lead to rapid engine failure. Thus, wrapped pipes may necessitate either re-jetting or a change in mapping depending on your bike’s fuel management system.
There is also a real risk of header and pipe damage due to excessive heat build-up. There are numerous reports of split and cracked exhausts that can be attributed to the use of exhaust wraps for motorcycles.
Exhaust Wrap Product Options
Heat Shield Lava Exhaust Wrap
Company’s Description: Made from crushed, melted, then fibered volcanic rock, our Lava motorcycle wrap has all the same benefits as motorcycle exhaust wrap with that trick carbon fiber look and improved durability.
Drag Specialties Heat Wrap
Company’s Description: Extreme heat (1,000 degrees F) fiberglass cloth for wrapping pipes or mufflers gives that "Old School" hot rod look to your bike as well as help keep the heat in and going out the back.
Moose Racing Exhaust Wrap