March 2008 - Performance Zone
HELP ME HELP YOU
By Performance Specialist Bruce C. Mallinson
When you purchase a used fleet truck that is not equipped with a turbo boost gauge and a pyrometer gauge, it’s almost impossible for us at Pittsburgh Power to diagnose a low power problem or a fuel mileage problem over the phone. Often, to make matters worse, these trucks have a single stack with a stock muffler which has been clogged for the past 200,000 miles. Because of the low power, the truck gets poor fuel mileage, so you call us or another diesel engine shop and start complaining about your truck. Here are some things you should know before you pick up the phone and make that call.
We need information from you to properly advise you. Without knowing what the turbo boost gauge reads at wide-open throttle, how many pounds of boost you’re using when cruising along the level and the exhaust gas temperature (EGT) readings, we can’t even come close to guessing what your problem is. Many times, you have already spent good money chasing the wrong problem, but you need to take the time and money to install a turbo boost gauge and a pyrometer gauge. These two simple gauges will tell you (and us) what is going on with your engine. Low power always means low fuel mileage – and that’s a quick way to go broke.
So, why are the turbo boost and pyrometer (EGT) gauges so important? Turbo boost is directly related to horsepower: The higher the boost, the greater the horsepower (assuming that the turbo is properly matched to the engine). It takes fuel to make boost and the engine must have enough boost to keep the exhaust gas temperature at 1300-1400 degrees on the hot side of an electronic engine, and 1000-1100 degrees on the cold side. If the turbo boost on a stock engine is low and the exhaust gas temperature is also low, then you have a fuel problem. In this scenario, the engine is not getting enough fuel, so we look for fuel-related problems. If the turbo boost is low and the exhaust gas temperatures are high, we now know there is a turbo boost problem but that the fuel system side of the engine is okay.
As you can see, by knowing what these two gauges are reading we can eliminate half of all the possible problems over the phone. Without the gauges and their readings, it’s just a crap shoot. The next time you think about going to your local dealer to check out your problems, consider this: they are going to hook their laptop to it and tell you that everything is within “spec” – but your truck still doesn’t run well and your fuel mileage is terrible. Well, the money you just spent to be told “it’s within spec” is about what you would have spent to install the two gauges in your truck. Worst of all, the dealership will install the latest and greatest settings into your ECM which will cause you to lose another half mpg and about 50 horsepower!
A turbo boost gauge and the installation kit to install it costs about $58 and the pyrometer gauge and installation kit is about $179. Both of these gauges are easy to install, even if you’re not mechanically inclined. I will even loan you the tools and show you where to hook the gauges to the engine. Heck, I’ll even loan you a piece of my parking lot if you don’t want to pay the two or three hours of labor to install the gauges! You should install them yourself. In fact, you should do most of the work on your truck. You will have a much better appreciation of your truck and you will understand it more when you work on it yourself.
Don’t just be a steering wheel holder. If you want to be an owner operator, get into it! Purchase some manuals and read up on your engine and drivetrain. You may not be able to rebuild the engine or transmission, but you will be able to speak more intelligently about them to service managers and mechanics. And speaking of your engine, when you call us with questions, you should know which engine you have – be prepared to tell us if it is a DD3 or DD4 Detroit, what the CPL number is (if you have a Cummins), or the first three digits of your engine’s serial number (if it’s a Cat). If you want us to diagnose your low power and low fuel mileage problem over the phone, we are going to need to know these sorts of things.
Here is a story for the owner operators out there who like to procrastinate. Randy Lange of Iowa is the proud owner of a 2003 Peterbilt with a Bridge MBN Caterpillar engine. When we first started talking, his “Bridge” Cat was low on power and fuel mileage. To help correct the problem, Randy purchased a Pittsburgh Power Performance Computer and then we built him a performance ECM to “un-bridge” his Cat Bridge engine. He then installed the FASS Fuel System to remove the air from his fuel and then replaced his stock mufflers with straight pipes. Randy’s expenditures totaled about $6,000 for the performance parts, but this year he will save 30 cents per mile. He runs about 700 miles per day and his savings this year will be about $50,000 in fuel. How about that for a pay raise? Fifty grand more in his pocket and his truck flies! If Randy had squeezed his nickels until the buffalo squealed, he would be out $50,000 this year, and now he loves his Cat-powered Peterbilt. If you would like to talk to Randy, his phone number is (712) 229-7654 – give him a call, he loves to talk about his truck!
Remember, being cheap with your truck will cost you thousands of dollars more in the end. And the longer you wait the more money you will waste! When you buy a cheap, used fleet truck, don’t expect it to perform like a tricked-out Peterbilt or Kenworth with a big engine. Unless you are willing to spend a little bit of money to improve it, your truck will never satisfy your need for performance and efficiency. If you have any performance-related comments or questions, please call me at Pittsburgh Power in Saxonburg, PA at (724) 360-4080 or send me an e-mail to bruce@pittsburghpower.com.