Ask Doug Thorley – Short vs. Long Tube Headers
We have been having an email conversation with Jamie Joyce, who manages Automotive R & D for Doug Thorley headers. In our previous post we got some interesting background information on the differences between Doug Thorley headers and a stock Toyota Tundra exhaust manifold. This time, we’ll get a chance to hear some of Jamie’s answers regarding the thorny issue of short tube headers versus long tube headers in the pickup truck world.
We started out by mentioning to Jamie that both the short and long tube header options offered by Doug Thorley appeared to offer a similar increase in low-end torque, with only a slight advantage going to the long tube units. This seemed to go against the conventional wisdom in the truck performance world that short tube headers can actually rob an engine of low rpm torque, especially in comparison to stock manifold designs.
Jamie told us that historically, most shorty header designs were only capable of offering horsepower and torque improvements from mid-range rpm’s onward. However, the Doug Thorley short tube headers were designed in a tri-y configuration that works to maintain a constant power increase throughout the entire power band. This was a special concern when the headers were being designed given that the Tundra is heavier than most of the vehicles that the company typically builds headers for.
Jamie also said that the decision to build a tri-y design stemmed from the reality that most Tundra drivers are going to be using their extra power in a practical application, rather than heading out to the race track where top end speed is at a premium.
Despite Jamie’s assurances that there were minimal performance differences between short tube and long tube headers, we did ask him whether drivers who were most concerned about maximum towing and hauling capacity – areas where low-end torque is especially important – should stick with a long tube design. He told us that he would recommend long tubes specifically in these cases because the units produced by Doug Thorley have shown a larger power increase right around the 3,000 rpm mark, which is where most tow rigs could use an extra boost.
Do Headers Help Gas Mileage?
Our last question for Jamie was regarding fuel economy improvements associated with a header install. We didn’t expect him to give us an exact mpg number – driving style plays such a large role in this type of performance calculation – but he was able to tell us that typically Thorley customers report improvements in the one to three mile per gallon range. He also said that given this efficiency increase, if you can keep your foot out of it then a set of headers from his company will pay for themselves in about a year through fuel savings alone.
It’s always great to be able to pick the brain of an exhaust expert like Jamie, and we really appreciate the time he took out of his busy schedule to answer our header questions. You will notice that we made sure to inquire about the benefits of short versus long tube headers in a Tundra application. This is a somewhat touchy topic amongst many in the Tundra community. Jamie himself appears to favor a long-tube approach for the Tundra, especially looking at how he answered our questions about towing and daily use.
That being said, he is quick to point out that the dyno data indicates that both the short and long-tube options provided by Doug Thorley outflow the stock factory units. The short versus long-tube debate it would seem is far from over – perhaps we can present a more in-depth investigation of the pros and cons of each design for the Tundra in the future.
Filed Under: Toyota Tundra Accessories