Long Tube Headers vs Short, What's Best for your Vette?
Any Corvette owner who attempts to modify their exhaust system will likely have heard of the debate on the merits of the long tube header as compared with the short tube header. Unlike an exhaust manifold, a header system is a series of runners that funnel the spent gas directly to the catalytic converter without mixing it beforehand. Because of this, the gases maintain velocity as they are channeled to the catalytic converter, resulting in a vacuum phenomena that is called "exhaust scavenging" which can help to draw spent fuel out of the engine more quickly.
Read on for a brief comparison between these two types of headers for a Corvette.
Long Tube Header Basics
Long tube headers take advantage of the periodic pulses of exhaust that come along with the process of exhaust scavenging in order to highlight the low-rpm torque. This is because the pulses tend to come less frequently when the engine is operating at a low rpm, allowing for a better match up with the time that it takes for the spent gases to flow through the long runner in a long tube header.
Short Tube Header Basics
Short tube headers take advantage of the fast pulses that occur at high rpm. This means that the short tube header helps to emphasize and strengthen the efficiency of the motor while it's operating at high rpm. However, short tube headers need to be a smaller diameter in order to maintain gas velocity for torque on the low end, meaning that the horsepower is limited compared to that of the long tube header.
Making a Selection
Obviously, there is no right answer. And judging from the CorvetteForum chatter, everyone seems to have an opinion. According to CorvetteForum user cdg200c5, long tube headers are generally preferable to short tube headers. Although long tube headers might be slightly more expensive and more difficult to install in a Corvette than short tube headers, the overall gain in power and the sound of the long tube headers operating is well worth it. Generally, other forum users agree. User peter pan suggests that long tube headers move the exhaust gas through to the catalytic converter more rapidly and efficiently, allowing the engine to operate at a high level across the board.
Other CorvetteForum members recommend short tube headers for a stock engine setup, and long tube headers for a specialized setup. There is also the concern that long tube headers are illegal in certain areas; Z06Electron mentions that long tube headers are likely to fail a visual inspection of your Corvette's exhaust system. Other users opt for short headers over the longer versions because they are easier to work around when you have to do maintenance under the car.
Ultimately, long tube headers provide an excellent high rpm advantage over short tube headers, though their cost, legal concerns and size may preclude some people from making use of these particular headers over shorter ones.