May 2004 - Performance Zone
May 2004 - Performance Zone
Did you ever think about the word “Passion”. In the trucking industry, we use manly words such as torque, horsepower, large car and hammer lane. But passion, that word rarely comes to our mind. Now let’s think about the meaning of passion. Passion is powerful - nothing was ever achieved without it, and nothing can take its place. No matter what you face in life, if your passion is great enough, you will find the strength to succeed. Without passion, life has no meaning. So put your heart, mind and soul into even your smallest acts. This is the essence of passion.
Now it’s time to talk about the 60 Series Detroit. Last month, Clyde Smith from Texas called me to talk about his poor fuel mileage from his 430 horsepower 60 Series Detroit in a Volvo. Clyde is 62 years old, has been driving trucks his entire life, and does not speed. His average speed is 60 to 62 mph. After asking him several questions we learned that his turbo boost would max out at 29 psi. He also told us that his pyrometer would only register 600 degrees on the cold side of the turbo, which is 300 degrees less than on the hot side. With just these numbers, we were able to determine that his turbo was too small and produced too much boost. Knowing that a 430 horsepower engine only requires about 25 psi of boost also helped us to determine that the turbo was too small. With a small turbo, the other problem is excessive back pressure in the exhaust manifold. And there is one more problem: the Volvo is equipped with one single stack. With one muffler, the exhaust pressure after the turbo to the muffler will be high, and not allow the engine to properly breathe.
Let’s face it, if you restrict the fuel flow, air intake or exhaust, the engine can’t perform as it was designed to. The engine has got to breathe to run free and obtain good fuel mileage.
So Clyde was able to get a load to Pittsburgh and came to our shop. We installed our test gauges and went for a ride up the hills on Rt. 28 along the Allegheny River. The gauges proved that our initial thoughts were correct - too much back pressure in the exhaust manifold and pipe. So now we had two restrictions hurting the performance and fuel mileage of the Detroit. Keep in mind that this 60 Series had been checked out by numerous Detroit shops and had been given a clean bill of health - many times.
Well, at 29 psi of turbo boost, there was 35 psi of back pressure in the exhaust manifold. What this was telling us is that the exhaust can’t get out of the exhaust manifold because the turbine housing of the turbo is too small. This is typical of quick response turbos. If this truck only did city delivery and never made it to the interstates, the turbo would be okay. Small turbos give you quick response and quick acceleration between traffic lights, but they are also hard on drive tires and drive shafts. But Clyde travels the open road and his driving style requires a larger turbo to reduce back pressure.
Not only is the back pressure too high in the exhaust manifold, the pressure in the exhaust pipe is 34 inches of water column. This is measured with a mono meter, the same instrument we use to measure blow by coming from the engine. What’s causing this problem? The muffler is too restrictive. So we removed his stock muffler and installed a straight through Donaldson muffler (see photo) and the back pressure dropped to 11 inches of water column. That is a 66% reduction in back pressure after the turbo just by installing a muffler that was designed for performance and is California legal. The truck now has a deep, throaty sound.
The turbo we had on order did not come in while Clyde was at our shop so we were not able to decrease the back pressure in the exhaust manifold. So now he will have to get another load back to Pittsburgh to get the turbo installed.
With the straight through muffler, Clyde’s Volvo has gained half of a gear on the hills and his fuel mileage has improved 1/10 mpg. Not bad for a $145.00 muffler. Please keep in mind that the turbo will make the biggest difference in fuel mileage, and the Pittsburgh Power Performance Computer he’s planning on installing will also improve the fuel mileage of this 60 Series Detroit. We will keep you informed on the progress of this project.
Yes, the Detroit Diesels now have their opportunity to perform with the other engines on the highway. Pittsburgh Power Performance Computers will add an additional 175 horsepower at the turn of the dial. The dial has 7 power settings and each setting will allow the engine to produce 25 more horsepower. You can increase your engine’s horsepower and torque as you are pulling the hill. We also have bigger injectors and turbos.
Take care and put some passion back into your career and driving! If you have any comments or questions, feel free to contact me at (724) 274-4080 or visit www.dieselinjection.net today.
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2004 10-4 Magazine and Tenfourmagazine.com
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